Duodenal Somatostatinoma: A Case Report and Review

Abstract

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.

Duodenal somatostatinoma presenting as obstructive jaundice with the coexistence of a gastrointestinal stromal tumour in neurofibromatosis type 1: a case with review of the literature

“…Whipple’s operation with regional lymphadenectomy should be considered for more aggressive or larger tumours. Radiation and chemotherapy are also treatment options, but most metastatic NETs are unresponsive to chemotherapy 33–37. For tumours <1 cm, there is no consensus regarding management, although endoscopic excision is considered a reasonable approach because of the low incidence of metastasis and lymph node involvement.…”

Somatostatin-producing duodenal carcinoma: Clinicopathological description of a case

“…Somatostatinomas may be sporadic (93,1%) or familial (6,9%) in association with neurofibromatosis tipe 1(NF1), multiple endocrine neoplasia type 1 (MEN 1) and Von Hippel-Lindau syndrome [3][4][5] . Unlike pancreatic somatostatinomas which are supposed to present with diabetes mellitus, cholelithiasis and steatorrhea also known as the "somatostatinoma syndrome", duodenal somatostatinomas produce local symptoms such as jaundice, abdominal pain and gastrointestinal bleeding or are asymptomatic.…”

“…Other sites of somatostatinomas include the duodenum (19%), the papilla of Vater (3%) the small intestine (3%), bronchus and liver 2 . Unlike pancreatic somatostatinoma which generaly produces a clinical syndrome (diabetes, steatorrhea, hypohloridria, dyspepsia) duodenal somatostatinoma may be completely asymptomatic 3,4 . In view of the rarity and the significance of the histologic diagnosis, we report a patient with malignant duodenal somatostatinoma with lymph node metastases that has been treated by surgery.…”

Gastric Somatostatinoma: An Extremely Rare Cause of Upper Gastrointestinal Bleeding

“…No data supports the benefit of adjuvant chemotherapy for the treatment of metastatic somatostatinoma, although few small case series reported that the synthetic somatostatin analogue octreotide, at 0.5 mg subcutaneously per day, had some benefits, including reduced diarrhea and other somatostatinoma symptoms, and stabilised tumor growth. Some studies on somatostatinoma reported no benefit from this treatment, which might be from a different subtype of somatostatin produced from the tumor 14,15. The overall 5-year survival for metastatic somatostatinoma was reported at approximately 40%, whereas that for small nonmetastatic lesions is 100% 15…”