Primary biliary neuroendocrine carcinoma: A rare presentation

Abstract

Presenter: Frances McCarron MD | St. Elizabeth Youngstown Hospital Background: Biliary neuroendocrine carcinomas make up approximately 0.2% of neuroendocrine neoplasm cases per the most recent WHO classification. Previous reports document tumors in the gallbladder and extra-hepatic bile ducts. There has been very little documentation of hepatic involvement of biliary NECs and even fewer reports of intra-hepatic biliary NENs. Given the rarity of these tumors, diagnosis can be mistaken for other malignancies such as cholangiocarcinoma, hepatocellular carcinoma or metastasis. Formal diagnosis, and thus targeted treatment, is usually delayed until post-operative pathology identifies the tumor. We present a rare case of poorly differentiated biliary neuroendocrine carcinoma (G3) with extensive hepatic involvement without evidence of distant metastasis. Methods: A 59-year-old female presented to her primary care office with symptoms of diverticulitis which was confirmed by CT of the abdomen and pelvis. An incidental 9.1cm lesion was identified involving segments 4B, 5, and 8 of the liver. The mass appearing hypodense on non-contrasted phase, with peripheral enhancement in the portal venous phase, was initially concerning for a pyogenic liver abscess secondary to diverticulitis. Differential diagnosis also included intra-hepatic cholangiocarcinoma, and less likely hepatocellular carcinoma or metastasis. A CT guided core biopsy of the lesion suggested a moderately differentiated adenocarcinoma of unknown primary. PET-CT scan showed hypermetabolic uptake of the mass without additional activity to suggest metastatic disease or alternate primary malignancy. Preoperative tumor markers were: CEA = 1.6, Ca 19-9 = 65, AFP = 6. The patient was referred to hepatobiliary surgery for resection. She underwent an en bloc cholecystectomy with central hepatectomy and intra-operative cholangiogram. Total operative time was 346 minutes, estimated blood loss = 600mL, pringle time = 15 minutes with a length of stay of 6 days. Her drain was removed on postoperative day 6. Results: Final pathology revealed a 12.5cm large cell neuroendocrine carcinoma involving the liver of biliary origin. Ki-67 uptake was present in 90% of tumor cells with 25 mitoses per 10 high power fields. An R0 resection was obtained. Pathology was also sent to University of Pittsburgh Medical Center whom concurred with our pathologists. She completed 4 cycles of adjuvant cisplatin and etoposide with no evidence for Conclusion: Biliary tract neuroendocrine neoplasms are exceedingly rare entities. It is estimated that approximately 0.5% of all NENs are of primary gallbladder origin and NEC make up 0.5% of all gallbladder carcinomas. Minimal reports of these tumors, make it difficult to identify the proper treatment modalities. In general, a poor survival rate and increased incidence of metastasis has been associated with G3 biliary NEC. We introduce a case of a rare presentation of a 12.5 cm large cell neuroendocrine carcinoma (G3) of biliary origin with hepatic involvement, no distant metastasis and good response to an R0 resection with 4 cycles of adjuvant chemotherapy. Further research, with long term follow up is needed to identify the optimal treatment plan for these rare tumors. However, this case poses a potential benefit for R0 resection with adjuvant chemotherapy.