[Diagnosis and treatment of extramammary Paget's disease]

Extramammary Paget's disease is a malignant tumor with the characteristic bright large atypical cells called Paget's cells, which proliferate within an intraepidermal lesion outside the breast. It occurs most frequently in the external genitalia, followed by perianal and axillary regions. The main clinical symptoms are erythema, erosion, pigmentation and depigmentation. Extramammary Paget's disease is commonly an intraepidermal neoplasm. However, if the tumor cells infiltrate into the dermis and form a clinically manifest nodule, it becomes an invasive carcinoma that can be classified as adnexal adenocarcinoma of the skin. Surgery with wide local excision is the first choice of treatment, and the prognosis is comparatively favorable in the early stages. However, when tumor cells infiltrate into the dermis and advance to Paget's carcinoma, it is referred to as adenocarcinoma of the skin and has a poor prognosis. We report an effective treatment of extramammary Paget's disease in advanced stages' including our case. No standard treatment with a significant effect has yet been established. There are few reports of cases responsive to chemotherapy, and treatment in advanced stages is extremely difficult at present.