Primary squamous cell carcinoma of the stomach with paraneoplastic leukocytosis: a case report and review of literature.

Apparently pure, primary squamous cell carcinoma of the stomach is exceedingly rare. To date, less than 100 cases have been reported. Here, we describe a case of primary squamous cell carcinoma arising in the gastric antrum of an 83-year-old man with persistent leukocytosis, which resolved on resection of the tumor. No foci of squamous metaplasia or gland-forming elements were identified in the resection specimen, although there was marked chronic gastritis with intestinal metaplasia. There was no evidence of Helicobacter, fungal, or parasitic infection. Immunohistochemical and in situ hybridization studies for human papillomavirus and Epstein-Barr virus were negative. This case suggests that gastric squamous cell carcinoma likely arises in the setting of long-standing, chronic inflammation, and like squamous cell carcinoma in other organ systems, may be associated with paraneoplastic leukocytosis.