Peripheral blood smear: indications, technique and interpretation | Clinique Omicron<\/title>\n<meta name=\"description\" content=\"The peripheral blood smear is a morphological examination of blood cells. Indications, abnormalities of red, white and platelet cells, and interpretation in Quebec.\">\n<meta name=\"keywords\" content=\"frottis sanguin p\u00e9riph\u00e9rique, frottis sanguin interpr\u00e9tation, frottis sanguin anomalies, frottis sanguin an\u00e9mie, frottis sanguin leuc\u00e9mie, frottis sanguin schizocytes, morphologie sanguine, examen sanguin p\u00e9riph\u00e9rique\">\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=Cinzel:wght@600&family=Poppins:wght@400;500;600;700&display=swap\" rel=\"stylesheet\">\n<style>\n.co-wrap * { font-family: 'Poppins', sans-serif; box-sizing: border-box; }\n.co-wrap { max-width: 1100px; margin: 0 auto; padding: 30px 0 60px; }\n.co-label { font-family: 'Cinzel', serif; font-size: 14px; font-weight: bold; letter-spacing: 1px; text-transform: uppercase; color: #4D6577; margin-bottom: 14px; display: block; }\n.co-wrap h1 { font-size: 32px; font-weight: 500; color: #323C52; margin: 0 0 22px; line-height: 1.2; }\n.co-intro { font-size: 16px; line-height: 1.75; color: #4D6577; margin-bottom: 36px; padding-bottom: 32px; border-bottom: 1px solid rgba(77,101,119,.2); }\n.co-wrap h2 { font-size: 20px; font-weight: 600; color: #323C52; margin: 32px 0 12px; }\n.co-wrap p { font-size: 15px; color: #4D6577; line-height: 1.7; margin-bottom: 14px; }\n.co-list { list-style: none; padding: 0; margin: 12px 0 24px; }\n.co-list li { font-size: 15px; color: #4D6577; padding: 10px 14px 10px 38px; margin-bottom: 8px; border-radius: 6px; position: relative; background: rgba(77,101,119,.06); border-left: 3px solid #4D6577; }\n.co-list li::before { content: \"\u2713\"; position: absolute; left: 12px; font-weight: 700; color: #4D6577; }\n.co-table { width: 100%; border-collapse: collapse; margin: 14px 0 22px; font-size: 14px; border-radius: 8px; overflow: hidden; table-layout: fixed; }\n.co-table thead tr { background: #323C52; color: #fff; }\n.co-table thead th { padding: 11px 16px; text-align: left; font-weight: 600; font-size: 13px; }\n.co-table tbody tr:nth-child(even) { background: rgba(77,101,119,.06); }\n.co-table tbody tr:nth-child(odd) { background: #fff; }\n.co-table td { padding: 10px 16px; color: #4D6577; border-bottom: 1px solid rgba(77,101,119,.12); font-size: 14px; vertical-align: top; }\n.co-table td:first-child { font-weight: 600; color: #323C52; }\n.co-infobox { display: flex; gap: 12px; background: rgba(77,101,119,.06); border-radius: 8px; border-left: 4px solid #4D6577; padding: 14px 18px; margin: 18px 0 28px; font-size: 14px; color: #4D6577; line-height: 1.65; }\n.co-infobox .ico { font-size: 18px; flex-shrink: 0; }\n.co-urgence { background: #fff8f8; border-left: 5px solid #c0392b; border-radius: 6px; padding: 20px 26px; margin: 24px 0 32px; }\n.co-urgence .co-urgence-titre { font-size: 13px; font-weight: 700; color: #c0392b; letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 10px; }\n.co-urgence p { color: #5a2020; font-size: 14px; margin: 0 0 10px; line-height: 1.7; }\n.co-urgence p:last-child { margin-bottom: 0; }\n.co-disclaimer { font-size: 13px; color: #8a9aaa; font-style: italic; border-top: 1px solid rgba(77,101,119,.15); padding-top: 24px; margin-top: 40px; line-height: 1.6; }\n<\/style>\n<\/head>\n<body>\n<div class=\"co-wrap\">\n <span class=\"co-label\">Laboratory Medicine & Hematology & Family Medicine<\/span>\n <h1>Peripheral blood smear<\/h1>\n\n <div class=\"co-intro\">\n The peripheral blood smear - also known as blood morphology or peripheral blood examination - is the microscopic study of circulating blood cells on a thin layer of blood smeared on a glass slide, stained with May-Gr\u00fcnwald-Giemsa (MGG) or Wright-Giemsa. It's one of the most informative and inexpensive laboratory tests in hematology - simultaneously assessing the morphology of red blood cells (erythrocytes), white blood cells (leukocytes) and platelets (thrombocytes), providing irreplaceable qualitative information that modern hematology machines can't fully reproduce. While the automated blood count (CBC) accurately measures quantitative parameters (hemoglobin + GMV + MCHT + WBC count with automated differential + platelets), it is the smear taken and read by an experienced hematologist or medical technologist that identifies subtle morphological abnormalities pointing to specific diagnoses: schizocytes (thrombotic microangiopathy - TTP + HUS); sickle cells (sickle-cell anemia); Howell-Jolly bodies (asplenia); circulating blasts (acute leukemia); S\u00e9zary cells (cutaneous lymphoma); intraerythrocytic Plasmodium (malaria). The peripheral blood smear is prescribed as a complement to the CBC when the latter shows unexplained abnormalities, alarms on the automaton, or as part of the work-up of a known or suspected hematological pathology. In Quebec, it is performed in hospital hematology laboratories and accredited private laboratories, on medical prescription.\n <\/div>\n\n <h2>Indications, technique and reading<\/h2>\n <ul class=\"co-list\">\n <li><strong>Clinical indications for peripheral blood smears :<\/strong> formal indications (smear test systematically recommended): unexplained anemia (Hb <100 g\/L in women + <120 g\/L in men), especially if microcytic or macrocytic + CBC abnormality with alarm on automaton (blasts + atypical cells + foreign bodies) + pancytopenia (affecting all three lineages) + severe isolated thrombocytopenia (30 G\/L) or leukopenia (185 g\/L male + >165 g\/L female) ; follow-up indications (smear useful for monitoring): follow-up of known hematological malignancies (leukemias + lymphomas + myelomas) + evaluation of response to treatment (chemotherapy + radiotherapy + biotherapies) + post-splenectomy monitoring + follow-up of constitutional hemolytic anemias (sickle cell anemia + thalassemia + hereditary spherocytosis) + post-transfusion monitoring of hemolytic patients.<\/li>\n <li><strong>Production techniques and reading zones :<\/strong> sampling: EDTA tube (purple cap - calcium-chelating anticoagulant) - smear ideally taken within one hour of sampling (rapid morphological degradation of leukocytes + changes in erythrocyte shape if delayed) - if delay unavoidable: store at +4\u00b0C for up to 24 hours; spreading technique: deposit of a drop of blood (2-4 \u00b5L) at one end of the slide + regular spreading with a second slide at 30-45\u00b0 \u2192 uniform thin layer 3-4 cm long + decreasing thickness from head to tail - air drying + automated (laboratory) or manual MGG staining; microscopic reading zones: thick zone (head of smear): cells superimposed - not readable - not interpretable; body zone (monolayer): optimal reading zone - cells well spread out + no superimposition + preserved morphology - systematic reading with \u00d7 10 then \u00d7 40 then \u00d7 100 objective (immersion oil) - differential leukocyte count (100 leukocytes minimum) + evaluation of erythrocyte and platelet morphology; tail zone (reading head): stretched and distorted cells - frequent artifacts (false schizocytes + acanthocytes) - not to be interpreted apart from the search for blasts and parasites; May-Gr\u00fcnwald-Giemsa (MGG) staining: erythrocytes \u2192 salmon-pink; mononuclear leukocytes \u2192 violet\/blue nuclei + blue-grey cytoplasm; granulocytes \u2192 specific granulations (neutrophils: pink-purple granulations + eosinophils: bright orange granulations + basophils: dark purple granulations)<\/li>\n <li><strong>Parameters systematically evaluated on the smear :<\/strong> erythrocytes : size (normocytes + microcytes + macrocytes) + shape (poikilocytosis - sickle cells + schizocytes + acanthocytes + echinocytes + elliptocytes + spherocytes + stomatocytes + targets) + staining (normochromia + hypochromia + polychromasia = polychromatophilic reticulocytes) + inclusions (Howell-Jolly bodies + basophilic granulations + Heinz bodies = denatured hemoglobin + intraerythrocytic Plasmodium) + roll formation (erythrocyte rolls = high fibrinogen + myeloma) ; leukocytes : manual differential (100 cells : neutrophil polynuclears + eosinophils + basophils + monocytes + lymphocytes + others) + nuclei morphology (neutrophil hypersegmentation = B12\/folate deficiency + D\u00f6hle bodies + toxic granulations = severe infection + blasts = leukemia + S\u00e9zary cells = lymphoma) + presence of immature cells (myeloma); platelets: estimated count (normal: 8-20 platelets per field \u00d7 10 = approx. \u00d7 15,000\/mm\u00b3 per visible platelet) + morphology (macro-platelets + micro-platelets + platelet aggregates = false EDTA-dependent thrombocytopenia) + granularity<\/li>\n <\/ul>\n\n <h2>Morphological abnormalities and their clinical interpretation<\/h2>\n <table class=\"co-table\">\n <colgroup><col style=\"width:200px;\"><col style=\"width:42%;\"><col><\/colgroup>\n <thead>\n <tr><th>Morphological abnormality<\/th><th>Description and microscopic appearance<\/th><th>Main etiologies and clinical orientation<\/th><\/tr>\n <\/thead>\n <tbody>\n <tr>\n <td>Morphological abnormalities of erythrocytes - microcytosis and hypochromia<br><small style=\"font-weight:400;color:#7a8fa0;\">VGM <80 fL - TCMH <27 pg<\/small><\/td>\n <td>Microcytes: small erythrocytes (diameter <6 \u00b5m) - GMV 1\/3 of erythrocyte diameter - MCHT <27 pg); appearance on smear depending on etiology: martial deficiency: microcytes + hypochromia + anisocytosis (size variation - high IDR) + mild poikilocytosis + rare target cells - progressive appearance according to severity of deficiency - at very advanced stage: ovalocytes + hypochromic elliptocytes; thalassemia minor (thalassemic trait \u03b1 or \u03b2): marked microcytosis + hypochromia + target cells (codeocytes - flat discs with dense central zone surrounded by a pale halo = corona hemoglobin) + hypochromic erythrocytes + anisocytosis + poikilocytosis - normal or slightly increased IDR (contrast with martial deficiency where IDR is elevated); inflammatory anemia (chronic disease): moderate microcytosis (VGM rarely <70 fL) + normo or slight hypochromia - morphological appearance often not very specific + martial workup (high ferritin + low CST) guides the diagnosis; lead intoxication (lead poisoning): microcytes + hypochromia + intraerythrocytic punctate basophilic granulations (basophilic stippling - precipitation of ribosomes) + anisocytosis - in children exposed to lead paint + in adults in industrial environments.<\/td>\n <td>Diagnostic approach to microcytosis on smear: martial workup (ferritin + serum iron + CST + TIBC) + hemoglobin electrophoresis (if thalassemia suspected - high HbA2 profile >3.5 % in \u03b2-thalassemia minor) + CRP (inflammation) + reticulocytes; martial deficiency (most common cause of hypochromic microcytosis): ferritin <30 \u00b5g\/L + CST 50 years or male or digestive symptoms) + malabsorption (celiac disease - serology) + inadequate intakes; thalassemia minor: CBC with normal IDR + very low VGM for Hb (Mentzer VGM\/GR ratio 13 \u2192 martial deficiency) + Hb electrophoresis - no iron treatment if pure thalassemia (risk of iron overload) - genetic counseling if pregnancy desired (risk of thalassemia major if both parents are carriers)<\/td>\n <\/tr>\n <tr>\n <td>Macrocytosis and macrocytic morphological abnormalities<br><small style=\"font-weight:400;color:#7a8fa0;\">VGM >100 fL - megaloblastosis + others<\/small><\/td>\n <td>Macrocytes: large erythrocytes (diameter >8.5 \u00b5m) - GMV >100 fL; megaloblastic macrocytosis (vitamin B12 or folate deficiency - antifolate drugs): macro-ovalocytes (large ovalocytes + well hemoglobinized - characteristic of megaloblastosis) + hypersegmentation of neutrophilic nuclei (\u22655 lobes in >5 % neutrophils OR presence of a neutrophil with 6 or more lobes - early and very specific sign of megaloblastosis). early and very specific sign of B12\/folate deficiency) + anisocytosis + poikilocytosis + rare teardrop erythrocytes (dacryocytes) - macrocytes are oval and not round (important distinction from non-megaloblastic macrocytes) ; non-megaloblastic macrocytosis (rounded macrocytes - without macro-ovalocytes or neutrophilic hypersegmentation) : alcoholism (frequent - direct mechanism on erythropoiesis + folic deficiency often associated - macrocytosis without severe anemia) + chronic liver disease (macrocytosis + acanthocytes = spur cells in advanced cirrhosis) + hypothyroidism + bone marrow aplasia (macrocytes + pancytopenia) + myelodysplastic syndrome (MDS - multiple dysplastic abnormalities + macrocytosis \u00b1 pseudo-Pelger-Hu\u00ebt hyposegmented neutrophils) + drugs: hydroxyurea + azathioprine + methotrexate + stavudine (ARV); marked reticulocytosis: pseudo-macrocytosis due to presence of polychromatophilic reticulocytes (larger than mature erythrocytes - occur during active bone marrow regeneration)<\/td>\n <td>Assessment of macrocytosis : serum vitamin B12 (normal >200 pmol\/L - sensitive but imperfect assay - a B12 in the low normal range 200-300 pmol\/L may mask a deficiency - supplement with plasma methylmalonic acid + homocysteine if in doubt) + folates erythrocyte folates (reflect intracellular reserves - more reliable than serum folates) + TSH (hypothyroidism) + liver work-up + GGT (alcohol) + reticulocytes + myelogram if MDS suspected (pancytopenia + multiple dysplastic smear abnormalities); treatment of B12 deficiency : cyanocobalamin or hydroxocobalamin IM 1,000 \u00b5g \u00d7 1\/d \u00d7 7d + 1,000 \u00b5g \u00d7 1\/week \u00d7 4 wk + 1,000 \u00b5g \u00d7 1\/month for life if irreversible cause (atrophic gastritis + gastrectomy + Biermer's disease) - or high-dose oral B12 1,000-2,000 \u00b5g\/d if dietary cause and intact digestive mucosa (passive absorption) - expected response: maximum reticulocytosis at D7 + Hb rise of 10-20 g\/L\/month + normalization of VGM in 2-3 months; treatment of folate deficiency: folic acid 1-5 mg\/d PO \u00d7 3-4 months (always be sure to exclude B12 deficiency before supplementing with folates alone - risk of aggravating B12 neuropathy if folates alone administered)<\/td>\n <\/tr>\n <tr>\n <td>Schizocytes and microangiopathic hemolytic anemia<br><small style=\"font-weight:400;color:#7a8fa0;\">Hematological emergency - PTT + SHU + CIVD<\/small><\/td>\n <td>Schizocytes (or schistocytes): erythrocyte fragments resulting from mechanical destruction of red blood cells in contact with intravascular fibrin filaments or abnormal surfaces (valve prostheses + vascular stenosis) - varied appearances: triangles + helmets + comma shapes + irregular fragments - always abnormal (pathological threshold: >0.1-0.2 % of erythrocytes according to ICSH 2012) - blood smear is the essential examination to detect them (automats do not identify them reliably); thrombotic microangiopathy (TMA) - diagnostic urgency: association schizocytes + thrombocytopenia + hemolytic anemia (very high LDH + collapsed haptoglobin + high indirect bilirubin) + negative direct coombs \u2192 confirmed TMA - 3 main entities to distinguish quickly as treatments are different: TTP (thrombotic thrombocytopenic purpura): severe ADAMTS13 deficiency (90 %; HUS (hemolytic uremic syndrome): MAT + dominant renal failure + few or no neurological manifestations - typical STEC HUS (E. coli O157:H7 - mostly children - after bloody diarrhoea) + atypical HUS (alternative complement pathway deficiency) - treatment: eculizumab (atypical HUS) + renal supportive care; DIC (see fibrinogen data sheet): schizocytes + thrombocytopenia + prolonged PT + low fibrinogen + very high D-dimer - treatment of cause<\/td>\n <td>Approach to schizocytes on smear: ADAMTS13 assay as a matter of urgency (before plasma exchange if possible, but do not delay treatment if TTP highly likely) + direct coombs + LDH + haptoglobin + bilirubin + PT + APTT + fibrinogen + D-dimer + renal function + urine (proteinuria + haematuria) + complement panel (C3 + C4 + CH50 + factor H + factor I) if atypical HUS suspected; schizocytes outside MAT: defective or dysfunctional mechanical valve prosthesis (paravalvular leakage) + severe aortic stenosis (Waring Blender mechanical intravascular hemolytic anemia - high shear stress on erythrocytes) + severe PAH + aortic coarctation; schizocytes + thrombocytopenia following stem cell allograft : transplant-associated thrombotic microangiopathy (TA-TMA) - diagnosis of exclusion + eculizumab discussed; importance of schizocyte quantification: >1 % = probable MAT + >5 % = severe MAT - ICSH 2012 recommendation: count 1,000 erythrocytes on the body area of the smear + express the result as a percentage<\/td>\n <\/tr>\n <tr>\n <td>Leukocyte abnormalities - blasts and abnormal cells<br><small style=\"font-weight:400;color:#7a8fa0;\">Leukemia - lymphoma - severe infections<\/small><\/td>\n <td>Circulating blasts: immature myeloid or lymphoid cells in peripheral blood - normally absent in blood - their presence is a major alarm on the automaton + must always be confirmed by smear + reading by a hematologist; myeloid blasts (acute myeloid leukemia - AML): large irregular nuclei + fine, loose chromatin + prominent nucleoli (1-3) + basophilic cytoplasm + azurophilic granulations + Auer rods (cytoplasmic red rods pathognomonic of AML - especially present in AML-M2 and APL) - blast count >20 % \u2192 AML according to WHO 2022 classification; lymphoid blasts (acute lymphoblastic leukemia - ALL): small to large regular nuclei + condensed chromatin + inconspicuous nucleoli + basophilic cytoplasm without granulations + PAS positive - ALL-B (more frequent in children) vs. ALL-T + immunophenotyping by flow cytometry mandatory for classification; chronic lymphocytic leukemia (CLL): persistent lymphocytosis + small, mature lymphocytes with monomorphic appearance + Gumprecht shadows (spreading fragile lymphoid cells - pathognomonic of CLL) + rare lymphoplasmacytoid forms; lymphoma in leukemic phase (S\u00e9zary cells + villeous lymphocytes + mantle lymphocytes); leukemic reaction (non-malignant): reactional hyperleukocytosis + myelemia (immature non-blastic forms: metamyelocytes + myelocytes - without blasts >5 %) \u2192 severe infectious context + inflammation + Marshall syndrome; toxic granulations + D\u00f6hle bodies: coarse blue-black cytoplasmic granulations in neutrophils \u2192 sign of severe bacterial infection + sepsis + burns<\/td>\n <td>Treatment of circulating blasts or suspected hyperleukocytosis: urgent hematology consultation - if blasts >20 % \u2192 acute leukemia \u2192 urgent hospitalization in hematology + complete workup (myelogram + cytogenetics + molecular biology) + prevention of tumor lysis syndrome (hyperhydration + allopurinol or rasburicase) + initiation of chemotherapy; leukostasis (acute leukemia with leukocytes >100 G\/L): life-threatening emergency - encephalopathy + respiratory failure + infarction - emergency leukapheresis discussed + immediate chemotherapy; eosinophilia (eosinophilic polynuclei >0.5 G\/L): reactive (allergy + parasitosis + asthma + IBD + drugs) or clonal (chronic eosinophilic leukemia - FIP1L1-PDGFRA mutation - treatment: imatinib + hypereosinophilic syndrome) - smear: mature eosinophils with characteristic orange granulations (reactive) vs. dysplastic eosinophils + immature precursors (clonal); severe neutropenia (<0.5 G\/L - agranulocytosis): major infectious risk \u2192 smear to assess morphology + myelogram if persistent \u2192 causes: drug-induced (chemotherapy + clozapine + propylthiouracil + ticlopidine) + autoimmune + bone marrow aplasia + Felty syndrome (RA + splenomegaly + neutropenia)<\/td>\n <\/tr>\n <tr>\n <td>Platelet abnormalities and intraerythrocyte parasites<br><small style=\"font-weight:400;color:#7a8fa0;\">Thrombocytopenia - malaria - Babesia<\/small><\/td>\n <td>Platelet morphological abnormalities: macroplatelets (giant platelets - diameter >4 \u00b5m): Bernard-Soulier syndrome (congenital platelet von Willebrand disease) + myeloproliferation + reactive bone marrow regeneration + immune thrombocytopenia (TPIa - macroplatelets reflect compensatory bone marrow production); microplatelets: Wiskott-Aldrich (syndrome of) + consuming DIC; platelet aggregates: EDTA-induced platelet clumping (false thrombocytopenia - frequent - 0.1-1 % of EDTA samples) \u2192 repeat CBC on citrate tube + check smear for absence of true thrombocytopenia \u2192 thrombocytopenia is artifactual if aggregates are numerous and free platelets rare; reduced platelet granularity (gray platelets): gray platelet syndrome - NBEAL2 mutation - absence of alpha granules - rare constitutional hemorrhagic thrombopathy; intraerythrocytic parasites - diagnostic emergency in the context of tropical travel: Plasmodium falciparum (severe malaria): delicate intraerythrocytic rings + small trophozoites in marginal position (attached to the membrane) + infected erythrocytes not enlarged + crescent-shaped gametocytes (banana - mature forms) + variable parasitemia (sometimes very high >5 % in P. falciparum) - MEDICAL EMERGENCY; Plasmodium vivax\/ovale: enlarged + deformed infected erythrocytes + Sch\u00fcffner granulations + ring or amoeboid trophozoites + schizonts; Babesia microti: intraerythrocytic Maltese cross tetrad (pathognomonic of Babesiosis) + may mimic P. falciparum - DO NOT treat. falciparum - DO NOT treat as malaria - treatment: atovaquone + azithromycin (or quinine + clindamycin if severe); Trypanosoma (African trypanosomiasis - sleeping sickness): flagellate extracellular trypomastigotes visible between erythrocytes<\/td>\n <td>Approach to thrombocytopenia on CBC: always check smear to rule out false EDTA thrombocytopenia (aggregates) - if true thrombocytopenia: look for schizocytes (MAT) + blasts (leukemia) + Gumprecht shadows (CLL) + erythrocyte morphological abnormalities (Evans syndrome = autoimmune hemolytic anemia + PTAI) + macroplatelets; primary immune thrombocytopenia (PIT - formerly PTI): isolated thrombocytopenia + smear: macro-platelets + no abnormalities in other lineages + no blasts + no schizocytes - diagnosis of exclusion - myelogram if >60 years or atypical signs - treatment : corticosteroids (prednisolone 1 mg\/kg\/d) + IVIG if bleeding emergency + eltrombopag\/romiplostim if corticoresistant + rituximab + splenectomy; malaria and smear: reference examination - optimal sensitivity: 3 thin smears + 3 thick drops 12 hours apart to exclude the diagnosis - results expected within the hour in Quebec (university hospital laboratories - 24-hour on-call availability) - rapid antigen detection test (RDT): sensitivity 90-99 % for P. falciparum + less sensitive for other species + does not replace smear for parasitaemia quantification and treatment follow-up<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n\n <div class=\"co-infobox\">\n <span class=\"ico\">\u2139\ufe0f<\/span>\n <span><strong>Peripheral blood smear vs. automated CBC - essential complementarity :<\/strong> automated CBC and peripheral blood smear are complementary, not interchangeable. The automated hematology system measures quantitative parameters (hemoglobin, GMV, cell count) with great precision, but cannot reliably identify qualitative morphological abnormalities - it generates alarms that need to be checked on the smear. In contrast, the smear is a semi-quantitative, qualitative examination that depends on the reader's expertise. In clinical practice in Quebec, the smear is performed automatically by laboratories when the CBC generates specific alarms (suspicious blasts + atypical cells + suspicious schizocytes + abnormal platelets). Physicians may also request it explicitly - the words \u00abperipheral blood smear\u00bb or \u00abblood morphology\u00bb on the prescription are sufficient.<\/span>\n <\/div>\n\n <div class=\"co-urgence\">\n <div class=\"co-urgence-titre\">Results requiring urgent medical assessment<\/div>\n <p><strong>Smear with circulating blasts + pancytopenia<\/strong> \u2192 probable acute leukemia \u2192 urgent hematology consultation the same day - don't wait.<\/p>\n <p><strong>Schizocytes >1 % + thrombocytopenia + hemolytic anemia<\/strong> \u2192 MAT (PTT or SHU) \u2192 urgent hospitalization - plasma exchange in PTT must be started within hours of diagnosis.<\/p>\n <p><strong>Intraerythrocytic parasites on return from tropical travel + fever<\/strong> \u2192 malaria \u2192 immediate medical emergencies - P. falciparum malaria can kill in less than 24 hours without treatment.<\/p>\n <\/div>\n\n <h2>Consult at Clinique Omicron<\/h2>\n <p>Clinique Omicron's doctors prescribe and interpret peripheral blood smears as part of the work-up for anemia, abnormal CBC, return from a trip with fever, or suspected hemopathy. Abnormal results are rapidly referred to a hematologist or internist, depending on the diagnosis. Consultations are available at several points of service in Quebec and via telemedicine. To book an appointment, visit <a href=\"https:\/\/cliniqueomicron.ca\">cliniqueomicron.ca<\/a>.<\/p>\n\n <p class=\"co-disclaimer\">The contents of this page are provided for information purposes only and do not replace the advice of a qualified healthcare professional. Interpretation of the peripheral blood smear requires expertise in morphological hematology and must always be correlated with the clinical context and other biological parameters.<\/p>\n<\/div>\n<\/body>\n<\/html>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"<p>Frottis sanguin p\u00e9riph\u00e9rique : indications, technique et interpr\u00e9tation | Clinique Omicron M\u00e9decine de laboratoire & H\u00e9matologie & M\u00e9decine de famille Frottis sanguin p\u00e9riph\u00e9rique Le frottis sanguin p\u00e9riph\u00e9rique \u2014 \u00e9galement appel\u00e9 morphologie sanguine ou examen du sang p\u00e9riph\u00e9rique \u2014 est l’\u00e9tude microscopique des cellules sanguines circulantes r\u00e9alis\u00e9e sur une mince couche de sang \u00e9tal\u00e9e sur une… <a href=\"https:\/\/cliniqueomicron.ca\/en\/frottis-sanguin-peripherique\/\" rel=\"bookmark\">Read More \"<span class=\"screen-reader-text\">Peripheral blood smear: indications, technique and interpretation | Clinique Omicron<\/span><\/a><\/p>","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"off","neve_meta_content_width":100,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","_themeisle_gutenberg_block_has_review":false,"_metasync_otto_title":"Frottis sanguin p\u00e9riph\u00e9rique : | Brossard | Clinique Omicron","_metasync_otto_description":"Le frottis sanguin p\u00e9riph\u00e9rique est l'examen morphologique des cellules sanguines. Indications, anomalies des globules rouges, blancs et plaquettes, et inter...","_metasync_otto_keywords":"","_metasync_otto_og_title":"Frottis sanguin p\u00e9riph\u00e9rique : | Brossard | Clinique Omicron","_metasync_otto_og_description":"Le frottis sanguin p\u00e9riph\u00e9rique est l'examen morphologique des cellules sanguines. Indications, anomalies des globules rouges, blancs et plaquettes, et inter...","_metasync_otto_twitter_title":"Frottis sanguin p\u00e9riph\u00e9rique : | Brossard | Clinique Omicron","_metasync_otto_twitter_description":"Le frottis sanguin p\u00e9riph\u00e9rique est l'examen morphologique des cellules sanguines. 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\n\t\t\t\t\t\n\n\n\n\nPeripheral blood smear: indications, technique and interpretation | Clinique Omicron<\/title>\n<meta name=\"description\" content=\"The peripheral blood smear is a morphological examination of blood cells. Indications, abnormalities of red, white and platelet cells, and interpretation in Quebec.\">\n<meta name=\"keywords\" content=\"frottis sanguin p\u00e9riph\u00e9rique, frottis sanguin interpr\u00e9tation, frottis sanguin anomalies, frottis sanguin an\u00e9mie, frottis sanguin leuc\u00e9mie, frottis sanguin schizocytes, morphologie sanguine, examen sanguin p\u00e9riph\u00e9rique\">\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=Cinzel:wght@600&family=Poppins:wght@400;500;600;700&display=swap\" rel=\"stylesheet\">\n<style>\n.co-wrap * { font-family: 'Poppins', sans-serif; box-sizing: border-box; }\n.co-wrap { max-width: 1100px; margin: 0 auto; padding: 30px 0 60px; }\n.co-label { font-family: 'Cinzel', serif; font-size: 14px; font-weight: bold; letter-spacing: 1px; text-transform: uppercase; color: #4D6577; margin-bottom: 14px; display: block; }\n.co-wrap h1 { font-size: 32px; font-weight: 500; color: #323C52; margin: 0 0 22px; line-height: 1.2; }\n.co-intro { font-size: 16px; line-height: 1.75; color: #4D6577; margin-bottom: 36px; padding-bottom: 32px; border-bottom: 1px solid rgba(77,101,119,.2); }\n.co-wrap h2 { font-size: 20px; font-weight: 600; color: #323C52; margin: 32px 0 12px; }\n.co-wrap p { font-size: 15px; color: #4D6577; line-height: 1.7; margin-bottom: 14px; }\n.co-list { list-style: none; padding: 0; margin: 12px 0 24px; }\n.co-list li { font-size: 15px; color: #4D6577; padding: 10px 14px 10px 38px; margin-bottom: 8px; border-radius: 6px; position: relative; background: rgba(77,101,119,.06); border-left: 3px solid #4D6577; }\n.co-list li::before { content: \"\u2713\"; position: absolute; left: 12px; font-weight: 700; color: #4D6577; }\n.co-table { width: 100%; border-collapse: collapse; margin: 14px 0 22px; font-size: 14px; border-radius: 8px; overflow: hidden; table-layout: fixed; }\n.co-table thead tr { background: #323C52; color: #fff; }\n.co-table thead th { padding: 11px 16px; text-align: left; font-weight: 600; font-size: 13px; }\n.co-table tbody tr:nth-child(even) { background: rgba(77,101,119,.06); }\n.co-table tbody tr:nth-child(odd) { background: #fff; }\n.co-table td { padding: 10px 16px; color: #4D6577; border-bottom: 1px solid rgba(77,101,119,.12); font-size: 14px; vertical-align: top; }\n.co-table td:first-child { font-weight: 600; color: #323C52; }\n.co-infobox { display: flex; gap: 12px; background: rgba(77,101,119,.06); border-radius: 8px; border-left: 4px solid #4D6577; padding: 14px 18px; margin: 18px 0 28px; font-size: 14px; color: #4D6577; line-height: 1.65; }\n.co-infobox .ico { font-size: 18px; flex-shrink: 0; }\n.co-urgence { background: #fff8f8; border-left: 5px solid #c0392b; border-radius: 6px; padding: 20px 26px; margin: 24px 0 32px; }\n.co-urgence .co-urgence-titre { font-size: 13px; font-weight: 700; color: #c0392b; letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 10px; }\n.co-urgence p { color: #5a2020; font-size: 14px; margin: 0 0 10px; line-height: 1.7; }\n.co-urgence p:last-child { margin-bottom: 0; }\n.co-disclaimer { font-size: 13px; color: #8a9aaa; font-style: italic; border-top: 1px solid rgba(77,101,119,.15); padding-top: 24px; margin-top: 40px; line-height: 1.6; }\n<\/style>\n<\/head>\n<body>\n<div class=\"co-wrap\">\n <span class=\"co-label\">Laboratory Medicine & Hematology & Family Medicine<\/span>\n <h1>Peripheral blood smear<\/h1>\n\n <div class=\"co-intro\">\n The peripheral blood smear - also known as blood morphology or peripheral blood examination - is the microscopic study of circulating blood cells on a thin layer of blood smeared on a glass slide, stained with May-Gr\u00fcnwald-Giemsa (MGG) or Wright-Giemsa. It's one of the most informative and inexpensive laboratory tests in hematology - simultaneously assessing the morphology of red blood cells (erythrocytes), white blood cells (leukocytes) and platelets (thrombocytes), providing irreplaceable qualitative information that modern hematology machines can't fully reproduce. While the automated blood count (CBC) accurately measures quantitative parameters (hemoglobin + GMV + MCHT + WBC count with automated differential + platelets), it is the smear taken and read by an experienced hematologist or medical technologist that identifies subtle morphological abnormalities pointing to specific diagnoses: schizocytes (thrombotic microangiopathy - TTP + HUS); sickle cells (sickle-cell anemia); Howell-Jolly bodies (asplenia); circulating blasts (acute leukemia); S\u00e9zary cells (cutaneous lymphoma); intraerythrocytic Plasmodium (malaria). The peripheral blood smear is prescribed as a complement to the CBC when the latter shows unexplained abnormalities, alarms on the automaton, or as part of the work-up of a known or suspected hematological pathology. In Quebec, it is performed in hospital hematology laboratories and accredited private laboratories, on medical prescription.\n <\/div>\n\n <h2>Indications, technique and reading<\/h2>\n <ul class=\"co-list\">\n <li><strong>Clinical indications for peripheral blood smears :<\/strong> formal indications (smear test systematically recommended): unexplained anemia (Hb <100 g\/L in women + <120 g\/L in men), especially if microcytic or macrocytic + CBC abnormality with alarm on automaton (blasts + atypical cells + foreign bodies) + pancytopenia (affecting all three lineages) + severe isolated thrombocytopenia (30 G\/L) or leukopenia (185 g\/L male + >165 g\/L female) ; follow-up indications (smear useful for monitoring): follow-up of known hematological malignancies (leukemias + lymphomas + myelomas) + evaluation of response to treatment (chemotherapy + radiotherapy + biotherapies) + post-splenectomy monitoring + follow-up of constitutional hemolytic anemias (sickle cell anemia + thalassemia + hereditary spherocytosis) + post-transfusion monitoring of hemolytic patients.<\/li>\n <li><strong>Production techniques and reading zones :<\/strong> sampling: EDTA tube (purple cap - calcium-chelating anticoagulant) - smear ideally taken within one hour of sampling (rapid morphological degradation of leukocytes + changes in erythrocyte shape if delayed) - if delay unavoidable: store at +4\u00b0C for up to 24 hours; spreading technique: deposit of a drop of blood (2-4 \u00b5L) at one end of the slide + regular spreading with a second slide at 30-45\u00b0 \u2192 uniform thin layer 3-4 cm long + decreasing thickness from head to tail - air drying + automated (laboratory) or manual MGG staining; microscopic reading zones: thick zone (head of smear): cells superimposed - not readable - not interpretable; body zone (monolayer): optimal reading zone - cells well spread out + no superimposition + preserved morphology - systematic reading with \u00d7 10 then \u00d7 40 then \u00d7 100 objective (immersion oil) - differential leukocyte count (100 leukocytes minimum) + evaluation of erythrocyte and platelet morphology; tail zone (reading head): stretched and distorted cells - frequent artifacts (false schizocytes + acanthocytes) - not to be interpreted apart from the search for blasts and parasites; May-Gr\u00fcnwald-Giemsa (MGG) staining: erythrocytes \u2192 salmon-pink; mononuclear leukocytes \u2192 violet\/blue nuclei + blue-grey cytoplasm; granulocytes \u2192 specific granulations (neutrophils: pink-purple granulations + eosinophils: bright orange granulations + basophils: dark purple granulations)<\/li>\n <li><strong>Parameters systematically evaluated on the smear :<\/strong> erythrocytes : size (normocytes + microcytes + macrocytes) + shape (poikilocytosis - sickle cells + schizocytes + acanthocytes + echinocytes + elliptocytes + spherocytes + stomatocytes + targets) + staining (normochromia + hypochromia + polychromasia = polychromatophilic reticulocytes) + inclusions (Howell-Jolly bodies + basophilic granulations + Heinz bodies = denatured hemoglobin + intraerythrocytic Plasmodium) + roll formation (erythrocyte rolls = high fibrinogen + myeloma) ; leukocytes : manual differential (100 cells : neutrophil polynuclears + eosinophils + basophils + monocytes + lymphocytes + others) + nuclei morphology (neutrophil hypersegmentation = B12\/folate deficiency + D\u00f6hle bodies + toxic granulations = severe infection + blasts = leukemia + S\u00e9zary cells = lymphoma) + presence of immature cells (myeloma); platelets: estimated count (normal: 8-20 platelets per field \u00d7 10 = approx. \u00d7 15,000\/mm\u00b3 per visible platelet) + morphology (macro-platelets + micro-platelets + platelet aggregates = false EDTA-dependent thrombocytopenia) + granularity<\/li>\n <\/ul>\n\n <h2>Morphological abnormalities and their clinical interpretation<\/h2>\n <table class=\"co-table\">\n <colgroup><col style=\"width:200px;\"><col style=\"width:42%;\"><col><\/colgroup>\n <thead>\n <tr><th>Morphological abnormality<\/th><th>Description and microscopic appearance<\/th><th>Main etiologies and clinical orientation<\/th><\/tr>\n <\/thead>\n <tbody>\n <tr>\n <td>Morphological abnormalities of erythrocytes - microcytosis and hypochromia<br><small style=\"font-weight:400;color:#7a8fa0;\">VGM <80 fL - TCMH <27 pg<\/small><\/td>\n <td>Microcytes: small erythrocytes (diameter <6 \u00b5m) - GMV 1\/3 of erythrocyte diameter - MCHT <27 pg); appearance on smear depending on etiology: martial deficiency: microcytes + hypochromia + anisocytosis (size variation - high IDR) + mild poikilocytosis + rare target cells - progressive appearance according to severity of deficiency - at very advanced stage: ovalocytes + hypochromic elliptocytes; thalassemia minor (thalassemic trait \u03b1 or \u03b2): marked microcytosis + hypochromia + target cells (codeocytes - flat discs with dense central zone surrounded by a pale halo = corona hemoglobin) + hypochromic erythrocytes + anisocytosis + poikilocytosis - normal or slightly increased IDR (contrast with martial deficiency where IDR is elevated); inflammatory anemia (chronic disease): moderate microcytosis (VGM rarely <70 fL) + normo or slight hypochromia - morphological appearance often not very specific + martial workup (high ferritin + low CST) guides the diagnosis; lead intoxication (lead poisoning): microcytes + hypochromia + intraerythrocytic punctate basophilic granulations (basophilic stippling - precipitation of ribosomes) + anisocytosis - in children exposed to lead paint + in adults in industrial environments.<\/td>\n <td>Diagnostic approach to microcytosis on smear: martial workup (ferritin + serum iron + CST + TIBC) + hemoglobin electrophoresis (if thalassemia suspected - high HbA2 profile >3.5 % in \u03b2-thalassemia minor) + CRP (inflammation) + reticulocytes; martial deficiency (most common cause of hypochromic microcytosis): ferritin <30 \u00b5g\/L + CST 50 years or male or digestive symptoms) + malabsorption (celiac disease - serology) + inadequate intakes; thalassemia minor: CBC with normal IDR + very low VGM for Hb (Mentzer VGM\/GR ratio 13 \u2192 martial deficiency) + Hb electrophoresis - no iron treatment if pure thalassemia (risk of iron overload) - genetic counseling if pregnancy desired (risk of thalassemia major if both parents are carriers)<\/td>\n <\/tr>\n <tr>\n <td>Macrocytosis and macrocytic morphological abnormalities<br><small style=\"font-weight:400;color:#7a8fa0;\">VGM >100 fL - megaloblastosis + others<\/small><\/td>\n <td>Macrocytes: large erythrocytes (diameter >8.5 \u00b5m) - GMV >100 fL; megaloblastic macrocytosis (vitamin B12 or folate deficiency - antifolate drugs): macro-ovalocytes (large ovalocytes + well hemoglobinized - characteristic of megaloblastosis) + hypersegmentation of neutrophilic nuclei (\u22655 lobes in >5 % neutrophils OR presence of a neutrophil with 6 or more lobes - early and very specific sign of megaloblastosis). early and very specific sign of B12\/folate deficiency) + anisocytosis + poikilocytosis + rare teardrop erythrocytes (dacryocytes) - macrocytes are oval and not round (important distinction from non-megaloblastic macrocytes) ; non-megaloblastic macrocytosis (rounded macrocytes - without macro-ovalocytes or neutrophilic hypersegmentation) : alcoholism (frequent - direct mechanism on erythropoiesis + folic deficiency often associated - macrocytosis without severe anemia) + chronic liver disease (macrocytosis + acanthocytes = spur cells in advanced cirrhosis) + hypothyroidism + bone marrow aplasia (macrocytes + pancytopenia) + myelodysplastic syndrome (MDS - multiple dysplastic abnormalities + macrocytosis \u00b1 pseudo-Pelger-Hu\u00ebt hyposegmented neutrophils) + drugs: hydroxyurea + azathioprine + methotrexate + stavudine (ARV); marked reticulocytosis: pseudo-macrocytosis due to presence of polychromatophilic reticulocytes (larger than mature erythrocytes - occur during active bone marrow regeneration)<\/td>\n <td>Assessment of macrocytosis : serum vitamin B12 (normal >200 pmol\/L - sensitive but imperfect assay - a B12 in the low normal range 200-300 pmol\/L may mask a deficiency - supplement with plasma methylmalonic acid + homocysteine if in doubt) + folates erythrocyte folates (reflect intracellular reserves - more reliable than serum folates) + TSH (hypothyroidism) + liver work-up + GGT (alcohol) + reticulocytes + myelogram if MDS suspected (pancytopenia + multiple dysplastic smear abnormalities); treatment of B12 deficiency : cyanocobalamin or hydroxocobalamin IM 1,000 \u00b5g \u00d7 1\/d \u00d7 7d + 1,000 \u00b5g \u00d7 1\/week \u00d7 4 wk + 1,000 \u00b5g \u00d7 1\/month for life if irreversible cause (atrophic gastritis + gastrectomy + Biermer's disease) - or high-dose oral B12 1,000-2,000 \u00b5g\/d if dietary cause and intact digestive mucosa (passive absorption) - expected response: maximum reticulocytosis at D7 + Hb rise of 10-20 g\/L\/month + normalization of VGM in 2-3 months; treatment of folate deficiency: folic acid 1-5 mg\/d PO \u00d7 3-4 months (always be sure to exclude B12 deficiency before supplementing with folates alone - risk of aggravating B12 neuropathy if folates alone administered)<\/td>\n <\/tr>\n <tr>\n <td>Schizocytes and microangiopathic hemolytic anemia<br><small style=\"font-weight:400;color:#7a8fa0;\">Hematological emergency - PTT + SHU + CIVD<\/small><\/td>\n <td>Schizocytes (or schistocytes): erythrocyte fragments resulting from mechanical destruction of red blood cells in contact with intravascular fibrin filaments or abnormal surfaces (valve prostheses + vascular stenosis) - varied appearances: triangles + helmets + comma shapes + irregular fragments - always abnormal (pathological threshold: >0.1-0.2 % of erythrocytes according to ICSH 2012) - blood smear is the essential examination to detect them (automats do not identify them reliably); thrombotic microangiopathy (TMA) - diagnostic urgency: association schizocytes + thrombocytopenia + hemolytic anemia (very high LDH + collapsed haptoglobin + high indirect bilirubin) + negative direct coombs \u2192 confirmed TMA - 3 main entities to distinguish quickly as treatments are different: TTP (thrombotic thrombocytopenic purpura): severe ADAMTS13 deficiency (90 %; HUS (hemolytic uremic syndrome): MAT + dominant renal failure + few or no neurological manifestations - typical STEC HUS (E. coli O157:H7 - mostly children - after bloody diarrhoea) + atypical HUS (alternative complement pathway deficiency) - treatment: eculizumab (atypical HUS) + renal supportive care; DIC (see fibrinogen data sheet): schizocytes + thrombocytopenia + prolonged PT + low fibrinogen + very high D-dimer - treatment of cause<\/td>\n <td>Approach to schizocytes on smear: ADAMTS13 assay as a matter of urgency (before plasma exchange if possible, but do not delay treatment if TTP highly likely) + direct coombs + LDH + haptoglobin + bilirubin + PT + APTT + fibrinogen + D-dimer + renal function + urine (proteinuria + haematuria) + complement panel (C3 + C4 + CH50 + factor H + factor I) if atypical HUS suspected; schizocytes outside MAT: defective or dysfunctional mechanical valve prosthesis (paravalvular leakage) + severe aortic stenosis (Waring Blender mechanical intravascular hemolytic anemia - high shear stress on erythrocytes) + severe PAH + aortic coarctation; schizocytes + thrombocytopenia following stem cell allograft : transplant-associated thrombotic microangiopathy (TA-TMA) - diagnosis of exclusion + eculizumab discussed; importance of schizocyte quantification: >1 % = probable MAT + >5 % = severe MAT - ICSH 2012 recommendation: count 1,000 erythrocytes on the body area of the smear + express the result as a percentage<\/td>\n <\/tr>\n <tr>\n <td>Leukocyte abnormalities - blasts and abnormal cells<br><small style=\"font-weight:400;color:#7a8fa0;\">Leukemia - lymphoma - severe infections<\/small><\/td>\n <td>Circulating blasts: immature myeloid or lymphoid cells in peripheral blood - normally absent in blood - their presence is a major alarm on the automaton + must always be confirmed by smear + reading by a hematologist; myeloid blasts (acute myeloid leukemia - AML): large irregular nuclei + fine, loose chromatin + prominent nucleoli (1-3) + basophilic cytoplasm + azurophilic granulations + Auer rods (cytoplasmic red rods pathognomonic of AML - especially present in AML-M2 and APL) - blast count >20 % \u2192 AML according to WHO 2022 classification; lymphoid blasts (acute lymphoblastic leukemia - ALL): small to large regular nuclei + condensed chromatin + inconspicuous nucleoli + basophilic cytoplasm without granulations + PAS positive - ALL-B (more frequent in children) vs. ALL-T + immunophenotyping by flow cytometry mandatory for classification; chronic lymphocytic leukemia (CLL): persistent lymphocytosis + small, mature lymphocytes with monomorphic appearance + Gumprecht shadows (spreading fragile lymphoid cells - pathognomonic of CLL) + rare lymphoplasmacytoid forms; lymphoma in leukemic phase (S\u00e9zary cells + villeous lymphocytes + mantle lymphocytes); leukemic reaction (non-malignant): reactional hyperleukocytosis + myelemia (immature non-blastic forms: metamyelocytes + myelocytes - without blasts >5 %) \u2192 severe infectious context + inflammation + Marshall syndrome; toxic granulations + D\u00f6hle bodies: coarse blue-black cytoplasmic granulations in neutrophils \u2192 sign of severe bacterial infection + sepsis + burns<\/td>\n <td>Treatment of circulating blasts or suspected hyperleukocytosis: urgent hematology consultation - if blasts >20 % \u2192 acute leukemia \u2192 urgent hospitalization in hematology + complete workup (myelogram + cytogenetics + molecular biology) + prevention of tumor lysis syndrome (hyperhydration + allopurinol or rasburicase) + initiation of chemotherapy; leukostasis (acute leukemia with leukocytes >100 G\/L): life-threatening emergency - encephalopathy + respiratory failure + infarction - emergency leukapheresis discussed + immediate chemotherapy; eosinophilia (eosinophilic polynuclei >0.5 G\/L): reactive (allergy + parasitosis + asthma + IBD + drugs) or clonal (chronic eosinophilic leukemia - FIP1L1-PDGFRA mutation - treatment: imatinib + hypereosinophilic syndrome) - smear: mature eosinophils with characteristic orange granulations (reactive) vs. dysplastic eosinophils + immature precursors (clonal); severe neutropenia (<0.5 G\/L - agranulocytosis): major infectious risk \u2192 smear to assess morphology + myelogram if persistent \u2192 causes: drug-induced (chemotherapy + clozapine + propylthiouracil + ticlopidine) + autoimmune + bone marrow aplasia + Felty syndrome (RA + splenomegaly + neutropenia)<\/td>\n <\/tr>\n <tr>\n <td>Platelet abnormalities and intraerythrocyte parasites<br><small style=\"font-weight:400;color:#7a8fa0;\">Thrombocytopenia - malaria - Babesia<\/small><\/td>\n <td>Platelet morphological abnormalities: macroplatelets (giant platelets - diameter >4 \u00b5m): Bernard-Soulier syndrome (congenital platelet von Willebrand disease) + myeloproliferation + reactive bone marrow regeneration + immune thrombocytopenia (TPIa - macroplatelets reflect compensatory bone marrow production); microplatelets: Wiskott-Aldrich (syndrome of) + consuming DIC; platelet aggregates: EDTA-induced platelet clumping (false thrombocytopenia - frequent - 0.1-1 % of EDTA samples) \u2192 repeat CBC on citrate tube + check smear for absence of true thrombocytopenia \u2192 thrombocytopenia is artifactual if aggregates are numerous and free platelets rare; reduced platelet granularity (gray platelets): gray platelet syndrome - NBEAL2 mutation - absence of alpha granules - rare constitutional hemorrhagic thrombopathy; intraerythrocytic parasites - diagnostic emergency in the context of tropical travel: Plasmodium falciparum (severe malaria): delicate intraerythrocytic rings + small trophozoites in marginal position (attached to the membrane) + infected erythrocytes not enlarged + crescent-shaped gametocytes (banana - mature forms) + variable parasitemia (sometimes very high >5 % in P. falciparum) - MEDICAL EMERGENCY; Plasmodium vivax\/ovale: enlarged + deformed infected erythrocytes + Sch\u00fcffner granulations + ring or amoeboid trophozoites + schizonts; Babesia microti: intraerythrocytic Maltese cross tetrad (pathognomonic of Babesiosis) + may mimic P. falciparum - DO NOT treat. falciparum - DO NOT treat as malaria - treatment: atovaquone + azithromycin (or quinine + clindamycin if severe); Trypanosoma (African trypanosomiasis - sleeping sickness): flagellate extracellular trypomastigotes visible between erythrocytes<\/td>\n <td>Approach to thrombocytopenia on CBC: always check smear to rule out false EDTA thrombocytopenia (aggregates) - if true thrombocytopenia: look for schizocytes (MAT) + blasts (leukemia) + Gumprecht shadows (CLL) + erythrocyte morphological abnormalities (Evans syndrome = autoimmune hemolytic anemia + PTAI) + macroplatelets; primary immune thrombocytopenia (PIT - formerly PTI): isolated thrombocytopenia + smear: macro-platelets + no abnormalities in other lineages + no blasts + no schizocytes - diagnosis of exclusion - myelogram if >60 years or atypical signs - treatment : corticosteroids (prednisolone 1 mg\/kg\/d) + IVIG if bleeding emergency + eltrombopag\/romiplostim if corticoresistant + rituximab + splenectomy; malaria and smear: reference examination - optimal sensitivity: 3 thin smears + 3 thick drops 12 hours apart to exclude the diagnosis - results expected within the hour in Quebec (university hospital laboratories - 24-hour on-call availability) - rapid antigen detection test (RDT): sensitivity 90-99 % for P. falciparum + less sensitive for other species + does not replace smear for parasitaemia quantification and treatment follow-up<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n\n <div class=\"co-infobox\">\n <span class=\"ico\">\u2139\ufe0f<\/span>\n <span><strong>Peripheral blood smear vs. automated CBC - essential complementarity :<\/strong> automated CBC and peripheral blood smear are complementary, not interchangeable. The automated hematology system measures quantitative parameters (hemoglobin, GMV, cell count) with great precision, but cannot reliably identify qualitative morphological abnormalities - it generates alarms that need to be checked on the smear. In contrast, the smear is a semi-quantitative, qualitative examination that depends on the reader's expertise. In clinical practice in Quebec, the smear is performed automatically by laboratories when the CBC generates specific alarms (suspicious blasts + atypical cells + suspicious schizocytes + abnormal platelets). Physicians may also request it explicitly - the words \u00abperipheral blood smear\u00bb or \u00abblood morphology\u00bb on the prescription are sufficient.<\/span>\n <\/div>\n\n <div class=\"co-urgence\">\n <div class=\"co-urgence-titre\">Results requiring urgent medical assessment<\/div>\n <p><strong>Smear with circulating blasts + pancytopenia<\/strong> \u2192 probable acute leukemia \u2192 urgent hematology consultation the same day - don't wait.<\/p>\n <p><strong>Schizocytes >1 % + thrombocytopenia + hemolytic anemia<\/strong> \u2192 MAT (PTT or SHU) \u2192 urgent hospitalization - plasma exchange in PTT must be started within hours of diagnosis.<\/p>\n <p><strong>Intraerythrocytic parasites on return from tropical travel + fever<\/strong> \u2192 malaria \u2192 immediate medical emergencies - P. falciparum malaria can kill in less than 24 hours without treatment.<\/p>\n <\/div>\n\n <h2>Consult at Clinique Omicron<\/h2>\n <p>Clinique Omicron's doctors prescribe and interpret peripheral blood smears as part of the work-up for anemia, abnormal CBC, return from a trip with fever, or suspected hemopathy. Abnormal results are rapidly referred to a hematologist or internist, depending on the diagnosis. Consultations are available at several points of service in Quebec and via telemedicine. To book an appointment, visit <a href=\"https:\/\/cliniqueomicron.ca\">cliniqueomicron.ca<\/a>.<\/p>\n\n <p class=\"co-disclaimer\">The contents of this page are provided for information purposes only and do not replace the advice of a qualified healthcare professional. Interpretation of the peripheral blood smear requires expertise in morphological hematology and must always be correlated with the clinical context and other biological parameters.<\/p>\n<\/div>\n<\/body>\n<\/html>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"<p>Frottis sanguin p\u00e9riph\u00e9rique : indications, technique et interpr\u00e9tation | Clinique Omicron M\u00e9decine de laboratoire & H\u00e9matologie & M\u00e9decine de famille Frottis sanguin p\u00e9riph\u00e9rique Le frottis sanguin p\u00e9riph\u00e9rique \u2014 \u00e9galement appel\u00e9 morphologie sanguine ou examen du sang p\u00e9riph\u00e9rique \u2014 est l’\u00e9tude microscopique des cellules sanguines circulantes r\u00e9alis\u00e9e sur une mince couche de sang \u00e9tal\u00e9e sur une… <a href=\"https:\/\/cliniqueomicron.ca\/en\/frottis-sanguin-peripherique\/\" rel=\"bookmark\">Read More \"<span class=\"screen-reader-text\">Peripheral blood smear: indications, technique and interpretation | Clinique Omicron<\/span><\/a><\/p>","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"off","neve_meta_content_width":100,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","_themeisle_gutenberg_block_has_review":false,"_metasync_otto_title":"Frottis sanguin p\u00e9riph\u00e9rique : | Brossard | Clinique Omicron","_metasync_otto_description":"Le frottis sanguin p\u00e9riph\u00e9rique est l'examen morphologique des cellules sanguines. 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