Carcinoma with signet ring cells of the esophagus.

A 55-year-old man with carcinoma with signet ring cells of the esophagus is described. The results of morphological examination are presented, and the classification and histogenesis of this rare tumor are discussed. Morphological examinations revealed this tumor to be composed of squamous, mucous-positive and signet ring cells. The signet ring cell had an intracytoplastic microcyst and bundles of tonofilaments. These findings suggested that the signet ring cell was an intermediate form of squamous and adenocarcinoma cells. The findings for these three components indicated that the tumor was a kind of mucoepidermoid carcinoma. Histological findings suggested this tumor's development originated from the esophageal mucosal epithelium.