Gastric somatostatinoma: an extremely rare cause of upper gastrointestinal bleeding

Abstract

A 49-year-old woman presented with chronic abdominal discomfort, significant weight loss, and chronic intermittent diarrhea. She suddenly developed massive upper gastrointestinal bleeding and was referred for further treatment. Endoscopy indicated a large mass in the upper gastric body with antral and duodenal bulb involvement. Endosonography showed a large well-defined isoechoic gastric subepithelial mass with multiple intra-abdominal and peripancreatic lymphadenopathy, suspected to be malignant on the basis of fine needle aspiration cytology. The tumor was surgically removed, and histopathology showed typical characteristics of a neuroendocrine tumor. On the basis of immunohistochemical staining, somatostatinoma, a rare neuroendocrine tumor, was diagnosed. Gastrointestinal bleeding is a rare presentation and the stomach is an uncommon tumor location.

Keywords: Endosonography; Neuroendocrine tumors; Somatostatinoma; Stomach metastasis.

Fig. 1

Endoscopic view showing (A) a large subepithelial gastric mass and (B) duodenal invasion with bleeding.

Fig. 2

(A) Endosonographic view showing a large isoechoic mass arising from the third and fourth layer, heterogeneous hypoechoic lymph nodes, suspected metastatic lymph nodes. (B) A computed tomography scan showing a large gastric mass with peripancreatic lymphadenopathy.

Fig. 3

(A) Gross pathology showing a tan-colored rounded mass with a rubbery consistency and whitish streaks of fibrosis. (B) Histopathology showing tumor cells with salt and pepper nuclear chromatin (H&E stain, ×20). The tumor was arranged in solid nests or in an acinar pattern. The tumor cells were cuboidal with ample granular eosinophilic cytoplasm including characteristic histologic feature of psammoma bodies (arrows) which supported somatostatinoma. (C) Synaptophysin showed diffuse positivity in the cytoplasm (×4). (D) Somatostatin staining showing a positive result (×40).