Progressive systemic sclerosis associated with primary small cell carcinoma of the stomach

A 64-year-old man with a 5-year history of progressive systemic sclerosis (PSS) was hospitalized because of melena. Radiological and endoscopic examinations showed an ulcerative lesion with sharply demarcated and raised margins in the fornix of the stomach. Tumor markers—serum carcinoembryonic antigen (CEA, 11.3 ng/ml) and neuron-specific enolase (NSE, 38.9 ng/ml) were elevated. Histological examination of endoscopic biopsy specimens (and of necropsy specimens) showed proliferation of atypical small round cells. Immunohistological examination of these cells showed they were positive for epithelial membranous antigen (EMA), and neuron-specific enolase (NSE), but negative for UCHL1, leukocyte common antigen (LCA), anti-leukocyte B-cell (MB1), and antileukocyte T-cell (MT1) antigens. Based on these histological and immunohistological tests, a definite diagnosis of small cell carcinoma of the stomach with PSS was established. Our case is a rare combination of PSS and gastric small cell carcinoma. We also reviewed the literature for the association between PSS and gastric cancer in Japanese patients.