Large duodenal somatostatinoma in the third portion associated with severe glucose intolerance

Four Neuroendocrine Tumor Types and Neuroendocrine Carcinoma of the Duodenum: Analysis of 203 Cases

BACKGROUND

Several types of neuroendocrine neoplasms (NENs) have been described in the duodenal tract, from low-grade tumors (NETs) to high-grade neuroendocrine carcinomas (NECs). A comprehensive analysis of histology, hormonal profile and prognostic parameters of a sufficiently large duodenal NEN series to cover all main kinds of neoplasms is however lacking.

METHODS

We collected a retrospective series of 203 duodenal wall and ampullary region NENs, from six specialized endocrine pathology centers. All were characterized histopathologically and histochemically, and 190 were followed for a median of 9 years.

RESULTS

Twenty-seven poorly differentiated NECs, mostly from the ampullary region, were identified and shown to lead to patient demise in a median of 10 months. Among 176 NETs, four subtypes were characterized, including 20 gastrinomas, 37 ampullary-type somatostatin-producing NETs (ASTs), 12 gangliocytic paragangliomas (GPs) and 106 nonfunctioning NETs (nfNETs). ASTs and GPs were mostly localized in the ampullary/periampullary region, while gastrinomas and nfNETs were mainly from the proximal duodenum. ASTs and gastrinomas showed high rates of local infiltration (especially lymphoinvasion and deep duodenal wall/pancreatic tissue invasion) and lymph node metastasis, while nfNETs had significantly lower and more size-dependent local invasive potential. Disease-specific survival differed significantly between NETs and NECs, though not among NET subtypes. NET cases with distant metastases (n = 23) were significantly associated with larger size, higher proliferative grade, lymphovascular invasion, deep invasion and local lymph node metastasis.

CONCLUSION

Our careful analysis of a large series of duodenal NENs identified five histologically and prognostically different histotypes of potential clinical relevance.

Pancreatic neuroendocrine tumors: contemporary diagnosis and management

Pancreatic neuroendocrine tumors (PNETs) are neoplasms that arise from the hormone producing cells of the islets of Langerhans, also known as pancreatic islet cells. PNETs are considered a subgroup of neuroendocrine tumors, and have unique biology, natural history and clinical management. These tumors are classified as 'functional' or 'non-functional' depending on whether they release peptide hormones that produce specific hormone- related symptoms, usually in established patterns based on tumor subtype. This manuscript will review pancreatic neuroendocrine tumor subtypes, syndromes, diagnosis, and clinical management.

Somatostatinoma of the Ampulla: An Incidental Postoperative Finding Following Colorectal Cancer Resection

Somatostatinoma of the gastrointestinal tract is a rare finding, especially arising from the ampulla of Vater. We present a man recently diagnosed with rectal adenocarcinoma who was found on imaging to have an ampullary mass. Histology and immunohistochemical staining of the biopsied tissue were consistent with a nonfunctioning somatostatinoma. The patient had neurofibromatosis, which have been reported in patients with ampullary somatostatinomas. Our case highlights the importance of gastrointestinal findings in those with underlying genetic conditions.

Duodenal somatostatinoma: a case report and review

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.

Somatostatinoma: clinico-pathological features of three cases and literature reviewed

Somatostatinoma is a rare endocrine tumor that comprises around 1% of all gastroenteropancreatic endocrine neoplasms. This paper gives an updated review on somatostatinoma and describes three sporadic cases of somatostatinoma located in the pancreas, duodenum, and jejunum. Approximately 200 case histories of somatostatinoma have been published, with the duodenum being the most frequent site, followed by the pancreas. Somatostatinomas may be sporadic or associated with neurofibromatosis type 1, Multiple Endocrine Neoplasia type 1, and Von Hippel-Lindau syndromes. Functional somatostatinomas release excessive amounts of somatostatin suppressing gallbladder motility and inhibiting the secretory activity of various endocrine and exocrine cell types. A triad of mild diabetes mellitus, cholelithiasis, and diarrhea/steatorrhoea characterizes the somatostatinoma or 'inhibitory' syndrome. Non-functional somatostatinomas tend either to be asymptomatic or to present with obstructive symptoms. These tumors are often malignant and by the time they are detected, nearly two-thirds have already metastasized to the regional lymph nodes or the liver. A comparison between our three cases and those in the literature provides useful insights into the clinical management of these patients. Interestingly, the jejunal somatostatinoma described here is the second case ever reported.