外陰のpapillary hidradenomaの1例

外陰部に発生する比較的まれなpapillary hidradenoma（乳頭状汗腺腫）の１例について報告する。症例は73歳の女性で小陰唇外側に胡桃大の皮膚腫瘤を認め，腫瘤摘出術を施行した。腫瘤内部には充実分を伴っており，組織学的には乳頭状増殖を示す腺構造で構成され，その腺腔は２層に重層した立方上皮で囲まれていた。上皮細胞の核異型は軽度であり，周囲組織への浸潤も認めず，papillary hidradenomaと診断された。しかし肉眼的所見および組織学的所見より腺癌と誤認される可能性があり，診断には注意が必要である。

Papillary hidradenoma is rare, benign, cystic, papillary apocrine gland tumor that occurs almost exclusively in women in the skin of the anogenital region. We report a case of a 73-year-old woman who presented with a progressively enlarging perianal nodule. The nodule appeared as walnut-sized skin tumor on the outside of the labium minus pudendi, and local excision was performed. Macroscopically, the inside portion of the tumor appeared solid. Microscopically, this region consisted of papillary adenomatous structures whose lumina were lined by 2 layers of cuboidal epithelial cells. Nuclear atypia and mitotic figures of these epithelial cells were rare and noninvasive. However, cells with this appearance may be mistaken for adenocarcinoma by both macroscopic and histologic views, and attention is necessary for an accurate diagnosis.