Gastric Somatostatinoma: An Extremely Rare Cause of Upper Gastrointestinal Bleeding
A 49-year-old woman with a history of type 2 diabetes mellitus for a few years presented with chronic abdominal discomfort and nausea for 1 year. She was treated for peptic ulcer disease but did not get better. Three months earlier, she complained of severe abdominal pain, significant weight loss, and chronic intermittent watery diarrhea. Abdominal sonography showed a large epigastric mass, 10×16 cm in size, with multiple hyperechoic nodules at both lobes of the liver and peripancreatic lymphadenopathy, suspected to be metastatic spread to the lymph nodes. Blood test results were within normal limits, and only hyperglycemia was noted. Blood tests for measuring hormone levels were not available in our institute. The patient was scheduled for a computed tomography (CT) scan of the upper abdomen. While she was waiting at the radiology unit, she developed hematemesis and was referred to the internal medicine department for further treatment. She was admitted, and the gastric lavage showed the presence of blood. Her hemoglobin level was 10 mg/dL. Endoscopy showed a large mass, approximately 15 cm in diameter, in the upper gastric body. The mass extended down to the antrum and duodenal bulb with blood oozing (). Next, endoscopic ultrasonography was performed, and a large well-defined isoechoic gastric subepithelial mass more than 13×8 cm in diameter was detected (). The mass arose from the third and fourth layers of the gastric wall. Multiple intra-abdominal and peripancreatic lymphadenopathy were detected, and the lesions varied in size from 8 to 25 mm. Fine needle aspiration was performed on the mass, and the cytology results led to a suspicion of malignancy. The CT scan showed a large soft tissue mass, with multiple liver metastases and intra-abdominal lymphadenopathy (). Finally, the patient underwent surgery. Gross pathology showed tumor involvement of the posterior wall of the stomach, with the tumor forming a large intramural multinodular mass (). Multiple well-circumscribed masses were detected at the pancreatic head and body and at the first part of the duodenum. Multiple liver nodules were also noted. Histopathology showed that the tumor was arranged in solid nests or in an acinar pattern infiltrating from muscularis propria of the stomach through the mucosa and extending to the duodenum. The tumor cells were cuboidal in shape with ample granular eosinophilic cytoplasm. Their nuclei were monotonous and bland, with salt and pepper nuclear chromatin, a typical characteristic of neuroendocrine tumors including positivity for typical characteristic of psammoma bodies (). Immunohistochemical staining for synaptophysin showed diffuse positivity in the cytoplasm (). Only a few tumor cells showed scattered positivity for somatostatin on immunohistochemistry (). A definitive diagnosis of somatostatinoma was made. The patient underwent distal gastrectomy with Billroth I anastomosis and cholecystectomy. However, she developed acute jejunal obstruction 2 weeks later due to intussusception from the jejunal leiomyoma and underwent gastrojejunostomy. She refused any further adjuvant chemotherapy or hormone therapy and received only palliative treatment. She passed away 8 months later because of massive liver metastasis.