A Rare Case of Primary Common Bile Duct Large Cell Neuroendocrine Carcinoma: A Case Report and Literature Review

Abstract

Introduction: Large cell neuroendocrine carcinoma (LCNEC) of the extrahepatic bile duct is extremely rare. There are only four reported cases in the Literature. LCNEC is a very aggressive tumor. The role of surgical resection remains unclear as metastasis is likely. We report the fifth case of LCNEC with initial presentation of painless jaundice. Case Report: A 65-year-old male presented to our hospital with two weeks history of painless jaundice and weight loss. He had a history of diabetes, hyperlipidemia, and paroxysmal atrial fibrillation. Patient denied smoking, alcohol use, or family history of cancer. A physical examination revealed icteric sclera and jaundice. The patient had no abdominal tenderness or palpable abdominal mass. Laboratory studies showed direct bilirubin 8.1(0.1-0.5 mg/dL); aspartate aminotransferase 151 (15-41 IU/L); alanine aminotransferase 330 (17-63IU/L); alkaline phosphatase 144 (15-41IU/L); and gamma-glutamyltransferase 1612 (7-50 IU/L). An abdominal computed tomography (CT) scan and abdominal ultrasound revealed dilatation of the common bile duct (CBD) to 9 mm without mass. An endoscopic retrograde cholangiopancreatography demonstrated a1.5 cm stricture in the distal common bile duct with upstream dilation to a maximum diameter of 15mm. Brushing and biopsy of the stricture was performed and a stent was placed. A positron emission tomography (PET) scan showed a small liver metastasis which was not visualized on the CT scan. Patient underwent laparoscopic liver biopsy. Histopathological and immunohistochemical findings of the stricture and liver metastasis were consistent with LCNEC. In our case, surgical resection was not performed due to metastasis. Patient was started on cisplatin and etoposide chemotherapy. Discussion: A primary neuroendocrine carcinoma (NEC) of the CBD is extremely rare because normal CBD mucosa does not contain neuroendocrine cells. Painless jaundice is a common presentation. LECNC is very aggressive tumor and has poor prognosis. Whipple procedure is commonly performed for localized disease. However, the role of surgery remains unclear as all four reported patients died of metastatic disease and liver failure despite surgical resection and adjuvant chemotherapy. Metastasis to the liver is common. CT scan might not show small metastatic lesions therefore staging with PET scan should be considered before surgical resection as it has higher mortality and morbidity.Table 1: Literature review of common bile duct large cell neuroendocrine carcinoma