Well-Differentiated Neuroendocrine Tumour of the Extrahepatic Bile Duct: a Case Report with Review of Literature

Extrahepatic biliary neuroendocrine tumors: A national cancer database analysis

Background

Extrahepatic biliary neuroendocrine tumors (EBNETs) are rare. We aimed to characterize EBNETs including factors associated with survival.

Methods

The National Cancer Database was queried for patients with EBNETs from 2004 to 2016. Patients who underwent resection were examined using Cox proportional hazards regression and the Kaplan-Meier method. We compared overall survival (OS) among patients with EBNETs to those with NETs from other primary sites.

Results

Overall, 223 patients with EBNETs were identified. Patients were predominantly male (n = 113, 50.7 %), white (n = 177, 79.4 %) and presented without distant metastasis (n = 182, 81.6 %). The majority underwent operation (n = 127, 57.9 %) with resection of the primary tumor (n = 89, 70 %). Among patients who underwent resection (n = 71), multivariable regression demonstrated older age (HR 1.11, 95 % C.I. 1.04-1.17), lymph node metastases (HR 1.19, 95 % C.I. 1.02-1.38) and poorly/undifferentiated tumors [HR 22.3, 95 % C.I. 3.78-131]) were associated with worse overall survival. Patients with EBNETs experienced abbreviated OS compared to patients with small bowel or pancreas NETs (p < 0.001), but improved OS when compared to patients with gallbladder NETs (p = 0.001).

Conclusions

Tumor differentiation and lymph node status significantly impact overall survival.

Gastrinoma of Cystic Duct: A Rare Association With Multiple Endocrine Neoplasia Type 1

Neuroendocrine tumors (NETs) of cystic duct are extremely rare, accounting for less than 2% of NET cases. The association of biliary tree NET and multiple endocrine neoplasm type 1 (MEN1) are even more rare. In this report, we described a case of a 65-year-old woman who was referred to our neuroendocrine outpatient clinic to investigate MEN1 after an incidental diagnosis of gastrinoma. Her medical history initiated 7 years earlier with severe peptic disease not responsive to proton pump inhibitor therapy. Endoscopic study revealed erosive antral gastritis, erosive duodenitis, bulbar ulcer and pyloric deformity. During follow-up she presented with abdominal pain, chronic diarrhea and weight loss; an ultrasonography was performed and showed only a cholelithiasis. She underwent a video laparoscopic cholecystectomy and all her symptoms were solved. Histopathological study found a 1.0 cm well differentiated NET (Ki-67 labeling index < 2%) located in cystic duct infiltrating the entire wall and subserosa. The MEN1 investigation revealed a primary hyperparathyroidism with a brown tumor in right iliac bone; the patient was referred to a total parathyroidectomy with autotransplantation. No evidence of pituitary tumor was found. The patient remains asymptomatic 24 months after surgery. To conclude, this case highlights an unusual presentation of a cystic duct primary NET gastrinoma in a MEN1 context.

Neuroendocrine Tumor of the Cystic Duct: A Rare and Incidental Diagnosis

Neuroendocrine tumors (NETs), also known as carcinoid tumors of the extrahepatic biliary tree, are extremely rare malignancies and account for 0.2% to 2% of all carcinoids of the gastrointestinal tract. The most common sites include NET in the common bile duct (CBD), followed by the perihilar region, cystic duct, and common hepatic duct (CHD). A review of the literature showed only eight cases of NETs of the cystic duct and we, hereby, present the ninth case of NET of the cystic duct in a 50-year-old woman. This was discovered incidentally after she underwent a laparoscopic cholecystectomy for her symptomatic gallbladder stones. The etiology is not known but the NETs are thought to arise from argentaffin cells (Kulchitsky cells) in the gastrointestinal tract or respiratory tract. It is possible that the rarity of these in this region may be explained by the very limited number of Kulchitsky cells there. Most of the patients are clinically asymptomatic, and the diagnosis is mostly made during surgery performed for other indications. Therefore, early recognition should be sought by differentiating the primary duct carcinoma of the bile or the cystic duct, if suspected or shown on the imaging studies because of the different therapeutic options and prognosis.