Summary and Conclusions
Extramammary Paget's disease of the perianal region is a rare, chronic, mucinous adenocarcinoma arising from an underlying apocrine sweat gland or duct, with secondary metastatic epidermal changes.
Diagnosis is made by histopathologic examination of the excised lesion. Other perianal dermatoses may produce the chronic, eroding, weeping, eczematoid skin changes usually seen in Paget's disease. The true pathogenesis of extramammary Paget's disease in an adnexal gland may be determined by serial section examination of the entire tumor and can be missed in the usual routine examinations.
Treatment should be early total excision of the lesion including adequate normal skin and subcutaneous margins. Microscopic examination of the tissue will establish the diagnosis and also determine the adequacy of the initial local excision. A radical abdominoperineal excision together with inguinal lymph-gland dissection will be necessary for the more advanced metastatic lesions. The prognosis is poor in the disseminated extramammary Paget's lesion.