Primary Vaginal Gastric-type Adenocarcinoma and Vaginal Adenosis Exhibiting Gastric Differentiation: Report of a Series With Detailed Immunohistochemical Analysis

We report a series of 11 vaginal glandular lesions exhibiting gastric differentiation, comprising 5 cases of adenocarcinoma and 6 of adenosis. All cases occurred in adults (aged 33 to 69) with no known history of diethylstilboestrol exposure. The vaginal adenocarcinomas exhibited morphologic features identical to gastric-type adenocarcinoma of the cervix, but 1 case additionally demonstrated basaloid and sarcomatoid components, which have not been previously reported in cervical gastric-type adenocarcinoma. Immunohistochemically, the adenocarcinomas were positive for MUC6 (4/5), PAX8 (3/5), CK7 (5/5), CK20 (1/5), CDX2 (5/5), CA19.9 (5/5), CEA (4/5), CA125 (5/5), and hepatocyte nuclear factor 1β (5/5). p16, estrogen receptor, and Napsin A were negative in all cases tested, whereas p53 exhibited mutation-type staining in 3/5 cases. In all 5 adenocarcinomas, a component of adenosis with benign or atypical nuclear features was identified; the adenosis displayed gastric morphology in 4 cases and tuboendometrial morphology in 1. The 6 cases of pure vaginal adenosis (without associated adenocarcinoma) all contained gastric-type mucinous glands together with tuboendometrial glands in 2 cases. There was focal intestinal differentiation with goblet cells in all 6 cases and neuroendocrine cells with eosinophilic granules in 3. Cytologic atypia was observed in 4/6 cases of pure vaginal adenosis. Immunohistochemically, the gastric-type adenosis (10 cases) was positive for MUC6 (10/10), e...
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research