Bowen’s disease and erythroplasia of Queyrat (EQ) are defined as intraepidermal squamous cell carcinoma, the latter occurring on the penis. The clinical appearance is that of a sharply demarcated, erythematous plaque that is persistent and slowly enlarging. Risk factors for the development of Bowen’s disease and EQ vary according to the site of disease, but generally include sun exposure, HPV (human papilloma virus) infection, arsenic exposure, radiation exposure, and HIV or other forms of immunosuppression.
The goals of treatment in both Bowen’s disease and EQ are cure and prevention of progression to invasive squamous cell carcinoma, while maintaining function and cosmesis. Invasive transformation of EQ is more common (10%) and metastasizes earlier than Bowen’s disease (3%). Multiple treatment options are available and no one treatment is ideal for all situations. Definitive treatment is surgical excision if the lesion is small and well defined. Mohs micrographic surgery (MMS) is recommended in the treatment of larger, ill-defined lesions, especially when preservation of normal tissue is crucial, as with EQ. Surgical ablation may be achieved with electrodesiccation and curettage, cryotherapy, or laser. Non-surgical options include imiquimod cream (a topical immunomodulator), topical 5-fluorouracil (5-FU), photodynamic therapy (PDT), and radiation therapy.
Standard of care requires that a follow-up period of no less than 5 years be observed to claim clinical cure of Bowen’s disease and EQ. Therefore, the extremely brief duration of follow-up for many studies is inadequate.