Well-differentiated endocrine tumor of the distal common bile duct: a case study and literature review

Abstract

Primary carcinoid tumors of the extrahepatic biliary tree are exceedingly rare, accounting for 0.2-2% of all digestive carcinoids. The authors in this study describe a case of biliary duct primary well-differentiated endocrine tumor in a 30-year-old man with symptoms of biliary obstruction and watery diarrhoea. Abdominal ultrasound showed a 2-cm solid lesion in the head of the pancreas, compressing the distal common bile duct. A computed tomography scan confirmed these findings, revealing the hypervascular pattern of the tumor. Gastrointestinal hormonal screening demonstrated an increase in plasma serotonin. The patient underwent standard pylorus-preserving pancreatoduodenectomy. Pathological examination showed a neuroendocrine tumor of the distal common bile duct measuring 1.8 cm in greatest dimension. The tumor cells were immunopositive for neuron-specific enolase (NSE), chromogranin A, synaptophysin, serotonin, and cytokeratin. Stains for gastrin and somatostatin were negative. Seven years later, the patient is well, with no evidence of disease. Given the site of these tumors and the difficulty in differentiating them from periampullary lesions, decisions as to the appropriate surgical approach may be problematic. After an exhaustive review of the literature, the authors conclude that pancreatoduodenectomy is the treatment of choice.

Neuroendocrine tumor of distal bile duct

“…1 However, in GIT, biliary tree (BT) is an unusual site for NET. 2 Further, in BT, distal common bile duct (CBD) is a very rare site indeed, as we report the 8th case in literature. 2 Ours is the first case where tangential portal vein excision was employed for its radical resection.…”

“…The cells are liberally spread in gut, whilst, sparingly so in the BT. 2 As the occurrence of NET parallels the distribution of neuroendocrine cells in the body, therefore, they are, although well known in gut, exceptional in BT (<80 documented cases). 2,4 Even in the BT, the distribution of NET in BT is variable.…”

“…2 As the occurrence of NET parallels the distribution of neuroendocrine cells in the body, therefore, they are, although well known in gut, exceptional in BT (<80 documented cases). 2,4 Even in the BT, the distribution of NET in BT is variable. It occurs in the ampulla, gallbladder, middle CBD, proximal CBD, distal CBD, and hepatic duct/cystic duct in decreasing order of incidence.…”

“…It occurs in the ampulla, gallbladder, middle CBD, proximal CBD, distal CBD, and hepatic duct/cystic duct in decreasing order of incidence. 2,4 These tumors are known to occur in the background of chronic inflammation with consequent metaplasia 2,4 ; however, gallstones and choledochal cyst have been associated only in a minority of cases. 2,5 These tumors are known to occur in middle age (median age 47 years) with slight female preponderance, as in our case.…”

“…2,4 These tumors are known to occur in the background of chronic inflammation with consequent metaplasia 2,4 ; however, gallstones and choledochal cyst have been associated only in a minority of cases. 2,5 These tumors are known to occur in middle age (median age 47 years) with slight female preponderance, as in our case. 2 Most tumors are nonfunctional with only four reported functional cases -one case had diarrhea and other three had recurrent peptic ulceration due to secretion of serotonin and gastrin, respectively.…”