Vulvar Paget's disease. Cytologic and immunohistologic diagnosis of a case.

An exfoliative smear from the vagina in a case of vulvar Paget's disease extending into the vagina and urethra was cytologically diagnosed as showing a large cell carcinoma. The malignant cells proved to be Paget cells by comparison of the cytologic specimen with subsequent biopsy specimens and by immunohistochemical studies using antibodies for glandular cytokeratin, epithelial membrane antigen, carcinoembryonic antigen and gross cystic disease fluid protein. These studies demonstrated that the Paget cell is probably of apocrine derivation. Exfoliative cytology and immunohistochemistry of exudative vulvar lesions may be helpful in the identification of Paget cells.