Neuroendocrine tumor of the common bile duct: a case report and review of the literature

Neuroendocrine Tumours of Extrahepatic Biliary Tract: Report of Four Cases with Literature Review

Neuroendocrine tumours (NETs) originating from extrahepatic bile duct are an extremely rare entity. They are typically slow growing tumours with malignant potential. Commonly presenting as obstructive jaundice, preoperative clinico-radiologic differentiation between extrahepatic biliary tract neuroendocrine tumours and cholangiocarcinoma is difficult and the final diagnosis is usually established after surgical histopathology and immunohistochemistry examination. R0 resection offers the only curative option with good long-term outcomes for well-differentiated NETs (grade1, grade2, and grade3) while the aggressive poorly differentiated neuroendocrine carcinoma (NEC) needs multimodality approach. We present our experience of management of four cases including three cases of grade II NET and one case of NEC undergoing surgical resection at a single centre with a short review of available literature.

Neuroendocrine tumour of the lesser omentum

A man in his early 20s presented to us in the outpatient department with a history of diarrhoea for 4 months. Investigations revealed elevated serum chromogranin levels and an intensely avid lesion in the gastrohepatic ligament in Gallium DOTATATE positron emission tomography (PET). The tumour was excised laparoscopically, and no other lesions were seen. The patient improved clinically and had a normal serum chromogranin level postoperatively. He is currently much improved at the 1year follow-up. We did an extensive workup to look for a primary tumour. It was concluded that it was a de novo tumour arising from the lesser sac. The recommended investigations in case of neuroendocrine tumour (NET) with unknown primary include blood investigations to look for the functional status of the tumour, histopathological examination, including immunohistochemistry, and radiological imaging, which must include a Gallium DOTATATE PET. An isolated NET of the lesser sac has not been reported in the literature.

Clinicopathological Features and Prognosis Analysis of Primary Bile Duct and Ampullary Neuroendocrine Neoplasms: A Population-Based Study from 1975 to 2016

BACKGROUND

The main purpose of this study is to analyze the clinicopathological features and prognosis factors of bile duct and ampullary neuroendocrine neoplasms (NENs).

METHODS

The relevant data were collected from the SEER database from 1975 to 2016. The Kaplan-Meier curve and Cox model were used for survival analysis. The nomogram was drawn to predict the survival rate. The calibration, discrimination and clinical utility of the nomogram were evaluated by calibration curve, the concordance index (C-index) and decision curve analysis (DCA).

RESULTS

A total of 340 cases were included in our research. According to Kaplan-Meier analysis, 1-year, 3-year and 5-year of overall survival (OS) were 77.3%, 61.9% and 58.4%, while 1-year, 3-year and 5-year of the disease-specific survival (DSS) were 82.7%, 69.3% and 66.9%, respectively. The multivariable analysis results showed that age, histological grade, SEER stage and surgery were independent predictors for either OS or DSS. The calibration curve and the C-index value indicated that the nomogram was well calibrated and had good discrimination. DCA showed that the model had ideal net benefits.

CONCLUSIONS

The age, histological grade, SEER stage and surgery were identified as independent prognostic variables for OS and DSS. After verification, nomogram has good predictive ability and clinical application value.

Neuroendocrine tumor of the common bile duct: A case report of extremely rare cause for obstructive jaundice

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Common Bile Duct is extremely rare site for primary Neuroendocrine tumors.

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WHO classification categorized neuroendocrine neoplasms of digestive tract into three subtypes: well differentiated neuroendocrine tumor, poorly differentiated neuroendocrine carcinoma and mixed adenoneuroendocrine carcinoma.

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The etiology of developing NET in the bile duct tissues is unknown but it is related to chronic inflammation with subsequent metaplasia.

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Surgical resection is the mainstay of the treatment.

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Postoperative chemotherapy using cisplatin and etoposide showed promising results.

Introduction

Neuroendocrine tumors (NET) of common bile duct are rare. There have been less than 100 cases reported worldwide.

Presentation of case

A 37-year-old female patient was referred to our center after six months of abdominal pain with no definite diagnosis. At initial presentation, she complained of increased abdominal pain, nausea, vomiting, oral intolerance to food and icteric sclera. Physical examination and laboratory tests were indicative of pancreatitis. At day four, she took retrograde cholangiopancreatography (ERCP) and a mid CBD stenosis or impacted stone was found. In order to locally investigate the lesion, Endoscopic Ultrasound (EUS) examination was performed which reported 16 × 12 mm isoechoic tumoral lesion at the middle of the CBD. In this regard we decided to perform ERCP-guided brushing biopsy of the lesion. The pathology report was highly suggestive for malignancy. She underwent resection of the mid portion of the CBD with Roux-en-Y hepaticojejunostomy, cholecystectomy and portahepatis lymph node dissection. The pathology report indicated that the CBD lesion was well-differentiated neuroendocrine tumor grade II.

Discussion

The exact etiology of developing NET in the bile duct tissues is not clear however cholelithiasis and congenital malformation of the biliary tract has been proposed to cause chronic inflammation with subsequent metaplasia which ultimately transforms into NET.

Conclusion

As there are very few cases of NETs of the CBD, no definite surgical or medical treatment is proposed. Currently, combination of radical surgical resection and lymph node dissection followed by chemotherapy is the treatment of choice.

Mixed adenoneuroendocrine carcinoma of the distal bile duct: a case report

BACKGROUND

Mixed adenoneuroendocrine carcinoma (MANEC) of the common bile duct (CBD) is very rare, with only 10 reported cases. Here, we report a case of MANEC of the distal bile duct (DBD) that was surgically resected under a diagnosis of cholangiocarcinoma (CCA).

CASE PRESENTATION

A 60-year-old male had epigastric pain and was admitted to our hospital for the treatment of a suspected CBD stone. Upon admission, laboratory findings revealed elevated hepatobiliary enzymes including serum aspartate aminotransferase, serum alanine aminotransferase, serum glutamyltransferase, and serum alkaline phosphatase. Both carcinoembryonic antigen and carbohydrate antigen 19-9 were negative. Computed tomography (CT) showed dilation of the CBD. Endoscopic retrograde cholangiopancreatography (ERCP) showed circumferential stenosis and a 5-mm elevated lesion in the DBD. Brush cytology showed atypical ductal cells, indicating adenocarcinoma (AC) of the DBD. Under a diagnosis of CCA of the DBD, a subtotal stomach-preserving pancreaticoduodenectomy was performed. Neither peritoneal dissemination nor lymph node metastasis was found. Microscopically, the lesion was seen to be composed of predominantly well-differentiated tubular AC in the superficial layer of the tumor, admixed with neuroendocrine carcinoma (NEC) in the deeper portion, indicating a diagnosis of MANEC of the DBD. After immunohistochemical staining, NEC components were positive for synaptophysin and CD56 and were for SSTR2, SSTR5, and mammalian target of rapamycin (mTOR). Three months postsurgery, postoperative adjuvant chemotherapy with S-1 was started. More than 3 years postsurgery, he is alive without recurrence.

CONCLUSIONS

MANEC is highly malignant, progresses rapidly, and has a poor prognosis. Preoperative diagnosis is difficult; therefore, identifying NEC components by immunohistochemical staining using resected specimens is important.

Mixed adenoendocrine carcinoma in the extrahepatic biliary tract: A case report and literature review

Neuroendocrine neoplasm (NEN) comprises a group of tumors that exhibit neuroendocrine phenotypes. NEN is subclassified into neuroendocrine tumor (NET), neuroendocrine carcinoma (NEC) and mixed adenoendocrine carcinoma (MANEC), based on histopathological parameters. NEN in the extrahepatic biliary tract (EHBT) is uncommon. Little is known about its clinicopathological features and prognostic indicators. The present study presented a case of MANEC in the distal common bile duct (CBD) and reviewed previous cases of NENs in the EHBT to characterize the clinical settings of this disease entity and to identify influencing factors of survival outcomes. A 64-year-old Chinese woman presented with abdominal pain and jaundice. Imaging studies demonstrated malignant stenosis in the distal CBD. Bile duct brush cytology revealed small clusters of atypical cells. Following an initial diagnosis of distal cholangiocarcinoma (CCA), the patient underwent pancreaticoduodenectomy. Histological analysis combined with immunohistochemical investigation of the resected specimen revealed a collision tumor that was composed of poorly differentiated adenocarcinoma and NEC. Each histological component accounted for >30% of the tumor. The definitive diagnosis was a MANEC in the distal CBD. Multiple intrahepatic and pulmonary metastases were observed postoperatively over 8 months. The patient succumbed to the disease 12 months after surgery. In conclusion, NEN occurs infrequently in the EHBT, with NET being the predominant type. NEN in the EHBT is extremely challenging to diagnose preoperatively due to its tendency to mimic CCA. Patients with NEN in the EHBT exhibited extremely distinct oncology outcomes according to pathological types. Additionally, old age (>60 years) and the presence of tumor recurrence were associated with decreased survival of patients with NEN.

Preoperative diagnosis of well-differentiated neuroendocrine tumor in common hepatic duct by brush cytology: A case report

The biological behavior of neuroendocrine tumors (NETs) is heterogeneous and differs from that of cholangiocarcinoma, which is the most common malignant tumor of the biliary tree. However, the preoperative diagnosis of NET in the biliary tree is extremely difficult and to our knowledge, diagnosis by brush cytology has not previously been reported. Herein, we first reported a case of biliary NET preoperatively diagnosed by brush cytology in a 33-year-old female patient. Imaging study revealed a 2.6-cm mass in the common hepatic duct. The brush cytology was characterized by loosely cohesive plasmacytoid tumor cells and scattered clusters of thin vascular septa. The tumor cells showed abundant cytoplasm and severe nuclear size variation but mitosis was not observed. Immunohistochemical staining of the cell block (CB) showed strong positivity for both synaptophysin and chromogranin A and a Ki-67 labeling index of 3.5%. The surgically resected bile duct mass was pathologically confirmed as NET, G2 with lymphovascular and perineural invasion of the tumor cells. The patient showed no evidence of tumor recurrence 10 months after operation without adjuvant chemotherapy. Suspicion of this rare tumor and immunohistochemical staining of the CB are important for the preoperative diagnosis of NET in the biliary tree.