Neuroendocrine tumors of the gallbladder: twelve cases in a single institution

We report a single center experience of 12 cases with neuroendocrine tumor (NET) of the gallbladder.

Twelve patients were diagnosed with gallbladder NET between July 1998 and February 2008 and assessed according to the WHO histological classification. Six patients underwent surgical resection and 6 patients underwent nonsurgical treatment.

There was one well-differentiated neuroendocrine carcinoma (NEC), 6 poorly differentiated NECs, and 5 mixed exocrine-endocrine carcinomas. All poorly differentiated NECs were small cell carcinomas; four patients had distant metastases at the time of diagnosis; and underwent chemotherapy. All five patients with mixed exocrine-endocrine carcinomas underwent operative treatments. The group with mixed exocrine-endocrine carcinomas and the group with poorly differentiated NECs didn't show a significant difference in overall survival (9.3 months vs. 8.0 months, respectively; p = 0.997). A patient with well-differentiated NEC had portal vein invasion and underwent aggressive curative surgery, but liver metastasis occurred after 1 month and she survived for 9.9 months.

NECs of the gallbladder are very aggressive tumors showing poor survival outcomes against current treatments. Further understanding on the clinical and pathologic characteristics of these NETs seems to be necessary to find more effective treatment modalities.