Primary liver somatostatinoma

Somatostatinoma syndrome: a challenging differential diagnosis among pancreatic tumors

Among the neuroendocrine neoplasia, the pancreatic somatostatin-producing tumors are very rare. Usually functional, these tumors produce the somatostatinoma syndrome, which encompasses diabetes mellitus, diarrhea/steatorrhoea, and cholelithiasis. Other symptoms may include dyspepsia, weight loss, anemia, and hypochlorhydria. All theses symptoms are explained by the inhibitory actions of the somatostatin released by tumoral cells originated from pancreatic delta cells or endocrine cells of the digestive tract. The diagnosis is easy to overlook since these symptoms are commonly observed in other more common syndromes. Besides the clinical features, diagnosis is based on serum determination of somatostatin, and imaging exams, such as ultrasound, computer tomography and positron emission tomography. Pathologic examination is characterized by the positivity of immunohistochemical reaction for synaptophysin, chromogranin, and somatostatin. These tumors can be classified according to tumor size, mitotic index, neural or vascular invasion, and distant metastases. The authors describe the case of a 61-year-old female patient who sought medical care because of a 6-month history of watery diarrhea, weight loss, and depression. She was diagnosed with diabetes mellitus 3 years ago. Imaging examination revealed a tumoral mass of 4 cm in its longest axis in the topography of the head of the pancreas and calculous cholecistopathy. The patient’s clinical status was unfavorable for a surgical approach. She died after 20 days of hospitalization. The definitive diagnosis was achieved with the autopsy findings, which disclosed a pancreatic somatostatinoma.

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.