Somatostatinomas are rare functioning carcinoid tumors that usually arise in the pancreas and duodenum. They are seldom associated with typical clinical symptoms; their diagnosis is confirmed only by histological and immunohistochemical studies and the presence of specific hormones. Two distinct clinicopathological forms of somatostatinoma exist: duodenal and pancreatic somatostatinomas. Clinically, compared to pancreatic somatostatinomas, duodenal somatostatinomas are more often associated with nonspecific symptoms and neurofibromatosis, but less often with somatostatinoma syndrome or metastasis. Histologically, duodenal somatostatinomas frequently have psammoma bodies in the tumor cells. We report a case of duodenal somatostatinoma in 58-year-old man with vague epigastric pain and nausea. He did not have diabetes, steatorrhea, or cholelithiasis. Abdominal computed tomography showed a 25-mm mass in the duodenum and 25-mm nodule in the liver. Endoscopic retrograde cholangiopancreatography showed a duodenal submucosal tumor. Although the endoscopic biopsies were free of malignancy, the patient subsequently underwent Whipple's operation for the duodenal mass. Examination revealed as a somatostatinoma using a special stain for somatostatin.
Cholangiopancreatography, Endoscopic Retrograde ; Duodenal Neoplasms/diagnosis/*pathology/surgery ; Humans ; Male ; Middle Aged ; Somatostatinoma/diagnosis/*pathology/surgery

Blood Glucose ; analysis ; Humans ; Hypoglycemia ; diagnosis ; etiology ; pathology ; Male ; Somatostatinoma ; complications ; diagnosis ; pathology ; Young Adult

Somatostatinoma is a rare neoplasm usually arising from the pancreas and duodenum which typically presents with indolent, nonspecific symptoms in the absence of systemic neuroendocrine manifestations that characterize somatostatinoma syndrome. It accounts for less than 1% of all gastrointestinal endocrine tumors with an annual incidence of 1 per 40 million. It is often associated with regional and/or portal metastasis at the time of diagnosis, and complete tumor resection is possible only in 60% to 70% of cases. We experienced a case of pancreatic somatostatinoma recently. A 51-year-old woman presented with right upper quadrant abdominal pain and loose stool for one month. A hypermetabolic lesion in the pancreatic head was detected on positron emission tomography-CT (PET-CT) scan. The tumor was resected by pylorus preserving pancreaticoduodenectomy. Immunohistochemical staining of the tumor tissue exhibited diffuse positivity for somatostatin, but was negative for insulin and glucagon. Herein, we report a case of pancreatic somatostatinoma diagnosed postoperatively.
Cholangiopancreatography, Endoscopic Retrograde ; Female ; Humans ; Middle Aged ; Pancreatic Neoplasms/*diagnosis/pathology ; Positron-Emission Tomography ; Somatostatinoma/*diagnosis/pathology ; Tomography, X-Ray Computed