A CASE OF SMALL CELL GASTRIC CANCER WHICH WAS DIFFICULT TO DISTINGUISH FROM A TUMOR OF THE HEAD OF THE PANCREAS

This report describes a case of submucosal small cell gastric cancer which was difficult to distinguish from a tumor of the head of the pancreas. A 50-year-old man complained of epigastric pain and underwent investigations which led to the discovery of a mass in the head of the pancreas. A submucosal tumor of the stomach or a tumor of the head of the pancreas were both considered possible, but no definite diagnosis could be made. The patient underwent laparotomy and pancreaticoduodenectomy because the mass proved difficult to resect. Perioperative gross findings provided no reliable evidence to establish a diagnosis. Histological examination of the resected specimen revealed a tumor, 8×7×6cm, extending outwards from the pyloric region on the lesser curvature of the stomach and infiltrating into the uncinate process of the pancreas. The histological diagnosis was primary small cell gastric cancer with partial differentiation to squamous cell carcinoma and adenocarcinoma. The tumor showed positive staining with Grimelius stain. Thirty cases of small cell gastric cancer, including this case, have been reported in Japan. Less than 0.2% of all gastric cancers are thought to be of this histological type. Gastric samll cell cancer often develops as a submucosal tumor and over 5cm in diameter at first detection; generally has a poor prognosis; and is often associated with distant metastasis. This patient had lymph node metastasis 8 months, and died 14 months following surgery.