Pancreatic polypeptide hypersecretion associated with a neuroendocrine carcinoma of the gallbladder

The authors report a case of a suspected pure pancreatic polypeptide-secret ing neuroendocrine carcinoma of the gallbladder. The tumor was initially in terpreted as an adenocarcinoma of the gallbladder, but was found to have a neuroendocrine component after review. The pathology supports the view that a primitive epithelial stem cell can express both epithelial and neuroendo crine characteristics and can differentiate into both an adenocarcinoma and a neuroendocrine carcinoma. Upon recurrence, the tumor produced symptoms d ue to local growth, but eventually metastasized and led to the death of the patient within 4 years. The patient was treated with chemoembolization fol lowed by the long-acting somatostatin analog octreotide acetate. The high s erum level of pancreatic polypeptide may have contributed to cholestasis an d cholelithiasis, Earlier measurement of serum hormone levels and identific ation of high pancreatic polypeptide levels may hare suggested the presence of residual tumor and led to closer fellow-up, imaging studies, and therap y.