Yoshisuke Kusumoto

Somatostatinoma of the duodenum

An adenocarcinoma of the second portion of the duodenum in a ear‐old male is presented. The patient was suffering from pain in the epigastrium. Immunofluorescent studies revealed that it consisted almost exclusively of cells with a distinctly positive somatostatin‐like immunoreactivity. Ultra‐structurally, the cytoplasm of the tumor cells had numerous large round granules (about 400 μm) with variable electron density. Most of these cells closely resembled the D cells normally seen in the duodenum and the islets of the pancreas, although a few argyrophil cells could be demonstrated by light microscopy. Radioimmunoassay of extracts of the tumor revealed a large amount of somatostatin (2260 pg/mg); substance P and VIP were detected also. Somatostatinoma has been known to occur in the pancreas, but this seems to be the first somatostatinoma found in the intestine.

DUODENAL SOMATOSTATINOMA Immunohistopathology and Review of Literature

A case of duodenal somatostatinoma is reported. The patient, a 54‐year‐old male, had complained of an epigastric pain due to gastric ulcer and a duodenal polyp was unexpectedly found at a gastrectomy. The polyp showed basically tubular adenocarcinoma, with negative argyrophil and argentaffin reactions. By an indirect immunofluorescent examination almost all of the tumor cells were revealed as somatostatin‐immunoreactive. Big somatostatin was also positive. Radioimmunoassay of the tumor indicated 6400 pg of somatostatin‐like immunoreactivity per milligram of wet tissue. This seems to be the second case of duodenal somatostatinoma, following the case reported by us previously.