Squamous cell carcinoma of the gastric stump. A case report and review of the literature

Abstract

Adenosquamous and pure squamous cell carcinomas of the stomach are very rare. This report is apparently the first published case of pure squamous cell carcinoma of the gastric stump. It occurred in a 67-year-old patient 37 years after Billroth II resection. This case satisfied the criteria established in the literature for the diagnosis of gastric squamous cell carcinoma. A diagnosis of adenosquamous carcinoma was excluded by extensive histologic investigation of a large number of tissue samples--a total 122 sections from 25 blocks--that revealed neither glandular structures nor mucin. The tumor stroma contained an unusually large number of eosinophils. Immunohistochemically, the tumor cells reacted with a monoclonal antibody against keratin (KL1), but not with antibodies against neuroendocrine or endothelial markers, or alpha 1-antichymotrypsin. The tumor may possibly originate from ectopic squamous epithelium, squamous metaplasia of the gastric mucosa, or an undifferentiated mucosal stem cell. However, we excluded an endothelial origin (which has been proposed by other authors) on the basis of immunohistochemical findings.