Bowen's disease

Non melanoma skin cancer ---> squamous cell carcinoma ---> Early skin cancer ---> Bowen's disease

Bowen's disease (squamous cell carcinoma in situ) presents as a fixed red plaque and represents an intra epidermal squamous cell carcinoma.
Epidemiology
Bowen's disease may occur at any age but is rare before the age of 30; most patients are aged over 60 at presentation. In the UK, it occurs predominantly in women (85% of cases).
Pathology
A number of different factors have been implicated in the aetiology of Bowen's disease. The age group and body sites affected are suggestive of a relationship with chronic exposure to ultraviolet radiation.
Histologically, keratinocytes show loss of polarity, atypia and increased mitotic rate with involvement of the entire thickness of the epidermis from basal layer to stratum corneum. The basement membrane remains intact.
Clinical features
Bowen's disease presents as solitary or multiple, gradually enlarging, well-demarcated erythematous macules, papules or plaques. The lesions usually have an irregular border with surface crusting or scaling. Approximately 75% of lesions are on the lower legs. They are most often asymptomatic, but may bleed. In the uncircumcised male, the lesions can present as smooth, red, velvety plaques on the glans penis (erythroplasia of Queyrat).
Investigations
The diagnosis is suggested on the basis of clinical features.
Skin biopsy
Histology is required to confirm the diagnosis.
Management
Ablation of the lesion
Treatment options for Bowen's disease include cryotherapy, curettage and cautery, excision, laser (CO2, argon and Nd:YAG) and topical 5-fluorouracil (applied once or twice daily as 5% cream for up to 2 months). All have recurrence rates of up to 10% and no treatment modality appears to be superior.
Prognosis
If Bowen's disease is untreated, most studies suggest a 3% risk of progression to invasive squamous cell carcinoma. Up to 50% of patients have other previous or subsequent skin malignancies, most commonly basal cell carcinoma. Genital Bowen's disease carries a higher risk of invasive cancer.