Diagnosis of HPV-negative, gastric-type adenocarcinoma of the endocervix.

Gastric-type adenocarcinoma of the cervix (GAS) is a novel, recently described subtype of endocervical adenocarcinoma. The clinical importance of accurate diagnosis of GAS stems from the observation that it confers worse prognosis than the usual-type endocervical adenocarcinoma. There are two unique characteristics of GAS: the tumor cells contain voluminous amounts of gastric-type mucins, and the tumor pathogenesis is not related to infection with high-risk human papillomavirus types. The histopathologic diagnosis of GAS is difficult; however, it may be confirmed by demonstration of intra-cytoplasmic gastric-type mucins using immunohistochemical staining with monoclonal antibody HIK1083. A protocol for HIK1083 immunostaining is described.