Extramammary Paget's disease.

Extramammary Paget's disease is an in situ skin and mucosal carcinoma frequently associated with and probably arising in a subjacent or regionally proximate carcinoma. Microscopic spread of tumor cells almost always extends beyond clinically apparent disease. Surgical treatment requires carefully planned, systematic excision under precise histologic control. An ideal treatment method remains to be developed. Inadequate excision usually results in recurrences that can be successfully treated by reexcision. Associated invasive carcinomas occur frequently, and mortality is high in these patients.