Polymorphous low-grade adenocarcinoma of the vulva and vagina: a tumor resembling adenoid cystic carcinoma.

We report the first case of a polymorphous low-grade adenocarcinoma (PLGA) occurring in the vulva and vagina of a 32-year-old woman. This tumor consisted of cellular lobules with distinct cribriform, papillary, and cystic patterns. Owing to its location and its distinct cribriform pattern, this lesion was initially diagnosed as an unusual variant of adenoid cystic carcinoma (ACC). However, this diagnosis was revised to PLGA when it was recognized that the cribriform, papillary and cystic patterns and their concomitant occurrence in the same lesion are characteristic of PLGA. PLGA should be added to the differential diagnosis of vulvar and vaginal neoplasia.