Dermatology — Skin Oncology
Bowen's Disease | Clinique Omicron Quebec
Bowen's disease is a squamous cell carcinoma in situ of the skin, meaning a malignant proliferation of keratinocytes confined to the epidermis, without crossing the basement membrane or invading the underlying dermis. It represents the most superficial and earliest form of cutaneous squamous cell carcinoma, constituting at this stage a high-grade precancerous lesion whose invasive potential remains contained as long as it is not neglected. First described by the American dermatologist John T. Bowen in 1912, this condition primarily affects fair-skinned adults over the age of 60, with a slight predominance in women. It typically presents as a well-defined, erythematous, scaly plaque that grows slowly and progressively, most often located on sun-exposed areas: the face, neck, décolletage, forearms, and legs. Bowen’s disease can also affect the genital and perianal mucous membranes, as well as the nails in less common forms. Its clinical significance stems from the risk of progression to invasive squamous cell carcinoma, estimated at 3 to 5% of untreated lesions, which carries a risk of lymph node metastasis. Early diagnosis and appropriate treatment lead to a cure in the vast majority of cases.
Causes and risk factors
Bowen's disease results from an accumulation of genetic mutations in epidermal keratinocytes, leading to abnormal clonal proliferation. Several etiopathogenic factors are recognized.
| Risk factor | Mechanism and specifications |
|---|---|
| Chronic ultraviolet exposure | Principal risk factor for lesions in photo-exposed areas; UVB radiation induces characteristic mutations in the TP53 tumor suppressor gene, found in the vast majority of Bowen's lesions; cumulative lifetime exposure is a determining factor. |
| Human papillomavirus (HPV) infection | Plays a major role in genital, peri-anal, and nail forms; high-oncogenic risk HPV genotypes (HPV 16, 18, 31, 33) are most frequently involved in genital and peri-ungual Bowen's disease; cutaneous HPV genotypes (5, 8) can be involved in extra-genital forms in immunocompromised patients. |
| Immunodepression | Risk multiplied by 5 to 10 in organ transplant patients on immunosuppressants, people living with HIV, and patients undergoing chemotherapy or biological treatments; lesions are often multiple, extensive, and progress more rapidly |
| Arsenic exposure | Chronic ingestion of inorganic arsenic (contaminated drinking water, arsenical pesticides, old arsenic-based medications) is associated with multiple Bowen's lesions in non-sun-exposed areas, often accompanied by arsenical palmoplantar keratoses; onset is 10 to 30 years after exposure. |
| Ionizing radiation exposure | Lesions that can appear in therapeutic irradiation fields several years after treatment; histological profile identical to other forms |
| Fair skin (phototype I and II) | Increased susceptibility to photo-induced keratinocyte DNA damage due to reduced melanin photoprotection |
| History of skin cancers | The presence of basal cell carcinoma, squamous cell carcinoma, or other actinic lesions (actinic keratoses) is associated with an increased risk of Bowen's disease, reflecting a widespread actinic-fragile skin condition. |
Clinical presentation
The clinical presentation of Bowen's disease varies depending on the anatomical site affected. Recognition of these distinct presentations is essential to avoid delaying diagnosis.
| Location | Characteristic clinical aspect | Special features |
|---|---|---|
| Smooth skin (sun-exposed areas) | Well-demarcated erythematous plaque, with a scaly, crusty, or warty surface, measuring from a few millimeters to several centimeters in diameter; irregular but distinct borders; slow growth over months to years | Most common form; often confused with psoriasis, nummular eczema, or seborrheic dermatitis; absence of itching in most cases |
| Face and scalp | Erythematous, scaly plaque, sometimes pigmented, which can mimic extensive actinic keratosis or Dubreuilh's melanoma. | Commonly located on fair-skinned individuals with a history of significant sun exposure |
| Genital region (male) | Velvety or scaly erythematous plaque on the glans, prepuce, or penis; historically referred to as Queyrat's erythroplasia when located on the male genital mucosa. | Higher risk of invasive transformation than in photo-exposed skin; frequent association with high-risk HPV |
| Genital region (female) and peri-anal | Whitish plaque (leukoplakia), erythematous, or mixed on the vulva, vagina, cervix, or anal margin; often multifocal | Often asymptomatic or itchy; screening by cervical-vaginal smear and colposcopy in a gynecological context; closely linked to HPV infection |
| Periungual and subungual region | Chronic periungual hyperkeratosis, fissures, partial nail plate detachment, erythematous periungual plaque resistant to usual antifungal treatments | Often overlooked and delayed in diagnosis; strongly associated with HPV (particularly HPV 16); should be considered in any unexplained chronic periungual lesion. |
ℹ️
Any erythematous squamous skin lesion that has persisted for more than 4 to 6 weeks without responding to usual topical treatments (corticosteroids, antifungals) should suggest Bowen's disease and warrant a dermatological consultation with biopsy. The absence of healing under empirical treatment is an important clinical warning sign, regardless of the initial appearance of the lesion.
Diagnosis
The definitive diagnosis of Bowen's disease is histological. A skin biopsy is essential and is the indispensable diagnostic step before any treatment.
- Punch biopsy or incisional biopsy: representative sample of the lesion, including the junction of healthy skin and lesion; histological examination in a pathology laboratory
- Characteristic histology: complete disorganization of epidermal architecture throughout its thickness (full-thickness keratinocytic dysplasia), dyskeratotic cells, atypical mitoses including in superficial layers, intact basement membrane without dermal invasion.
- Dermatoscopy: Non-invasive examination guiding clinical suspicion before biopsy; suggestive aspects of glomerular vessels (in clusters) on an erythematous, squamous background, irregular surface distribution
- Mapping of multiple lesions: standardized clinical photographs to document extent and track progression, particularly useful for widespread lesions or genital locations
- HPV PCR on biopsied tissue: indicated in cases of genital or periungual lesions or in immunocompromised patients to identify the viral genotype and adapt monitoring.
- Staging only if suspicion of invasive transformation: palpable regional lymph nodes, thickened and indurated lesion, central ulceration suggestive of dermal invasion
Differential diagnosis
| Affection | Distinguishing elements |
|---|---|
| Plaque psoriasis | Multiple erythematosquamous plaques, symmetrical distribution, affecting elbows and knees, personal or family history, response to topical corticosteroids and antipsoriatic treatments |
| Nummular eczema | Erythematous, oozing, pruritic, often bilateral, round plaques, atopic context, response to topical corticosteroids. |
| Actinic keratosis | Squamous precancerous lesion in a sun-exposed area, but with partial (non-full thickness) histological dysplasia, unlike Bowen's disease; distinction confirmed by biopsy. |
| Invasive squamous cell carcinoma | Thickened, indurated, ulcerated, or bleeding lesion; basement membrane breach on histology with dermal invasion; higher metastatic risk |
| Dubreuil's melanoma (lentigo maligna) | Pigmented patch with irregular borders on the faces of elderly individuals; different dermatoscopy and histology; absence of scales |
| Mycosis fungoides (cutaneous T-cell lymphoma) | Chronic erythematous plaques resistant to topical treatments; histology with characteristic epidermotropic T-lymphocytic infiltrate; immunohistochemistry necessary |
| Dermatophytosis (ringworm, tinea corporis) | Erythematous plaque with active, circinate borders, pruritic, responsive to antifungals; positive mycological examination. |
Treatment options
The choice of treatment depends on the size, location, and number of lesions, the patient's immune status, their comorbidities, and their preferences. All options aim for complete eradication of the lesion with maximal preservation of surrounding healthy tissue.
| Treatment | Terms and conditions | Recovery rate and remarks |
|---|---|---|
| Surgical excision | Resection of the lesion with surgical margins of 3 to 5 mm; histopathological examination of the resection margins; reference treatment for small to medium-sized surgically accessible lesions | Recovery rate greater than 95% for %; the advantage of providing a complete histological specimen confirming margins; residual scarring depending on the location |
| Mohs micrographic surgery | Excision with real-time intraoperative histological margin control; indicated for extensive lesions, anatomical sites with limited tissue (face, ears, fingers), recurrent or ill-defined lesions | Highest cure rate, over 97% for %; maximum preservation of healthy tissue; specialized center required |
| Liquid nitrogen cryotherapy | Liquid nitrogen application in repeated freeze-thaw cycles; simple, fast technique, achievable in consultation; indicated for small lesions in non-critical areas | 75% to 90% cure rate for %; higher risk of recurrence than surgery; hypopigmented scar is common; moderate post-treatment pain |
| Topical 5-fluorouracil (5-FU) | 5% % cream (Efudex) applied once or twice daily for 4 to 12 weeks; inhibits DNA synthesis in abnormal keratinocytes; indicated for extensive or multiple lesions that are difficult to treat surgically | Response rate of 70% to 85% (%); intense local inflammatory reaction (erythema, exudation, crusting) is expected and indicates efficacy; close monitoring is required |
| Topical imiquimod (5 %) | Immunomodulator that activates innate and adaptive local immune responses; apply 3 to 5 times per week for 6 to 16 weeks; particularly useful for genital lesions and patients refusing surgery | A cure rate of 70% to 80% for %; frequent local inflammatory reaction; higher long-term recurrence rate than surgery |
| Photodynamic therapy (PDT) | Application of a topical photosensitizer (aminolevulinic acid, methyl aminolevulinate) followed by illumination with a specific wavelength light source; selective destruction of dysplastic cells; repeated sessions at 1 to 4 week intervals | 80–90% cure rate for %; excellent cosmetic results, particularly suitable for extensive lesions on the face and lower limbs in the elderly; pain during treatment varies by patient |
| Curettage and electrodessication | Mechanical curettage of the lesion followed by electrocoagulation of the base; rapid and simple technique in consultation; indicated for small, superficial lesions. | Recovery rate of 80–90% for %; no histological specimen available to verify margins; scarring possible |
ℹ️
Queyrat's erythroplasia (Bowen's disease of the male genital mucosa) carries an estimated risk of progression to invasive squamous cell carcinoma of 10 to 30%, which is significantly higher than that of extragenital skin lesions. This higher risk, combined with the sensitive location, warrants specialized dermatological care and rigorous, long-term post-treatment follow-up.
Post-treatment surveillance
- 3-month follow-up consultation after treatment completion to verify complete clinical healing; follow-up biopsy if there is doubt about lesion persistence.
- Annual full-body skin examination by a dermatologist due to risk of new actinic lesions or local recurrence
- Clinical examination of regional lymph nodes at each appointment for early detection of possible invasive transformation with nodal extension.
- Rigorous and permanent photoprotection: high SPF sunscreen (SPF 50+), photoprotective clothing, avoidance of sun exposure during peak sunlight hours
- Enhanced gynecological screening (colposcopy, cervical-vaginal smear) in cases of genital Bowen's disease or documented high-risk HPV infection
- HPV vaccination to discuss by age and vaccination status, particularly in cases of HPV-related genital Bowen's disease in previously unvaccinated individuals
- In case of immunosuppression: close dermatological monitoring every 6 months, discussion with the transplant team about optimizing the immunosuppressive regimen
Consult at Clinique Omicron
When faced with a persistent erythematous scaly skin lesion that is resistant to usual treatments or appears atypical, Clinique Omicron physicians can perform an initial clinical assessment, refer to dermatology for a diagnostic biopsy, and coordinate appropriate therapeutic management. Annual dermatological follow-up for actinic lesions and a history of skin cancers is available at several Clinique Omicron service points in Quebec. Book an appointment online or by phone at one of the Clinique Omicron locations, whether on the South Shore, in Montreal, or at one of the other branches in Quebec.
The content of this page is provided for informational purposes only and is not intended to replace the advice of a qualified healthcare professional. Consult a physician for any symptoms, questions or decisions you may have regarding your health.
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