Carcinoid tumor of the gallbladder associated with adenocarcinoma

A case of carcinoid tumor of the gallbladder associated with adenocarcinoma in a 56-year-old man is reported and a review of the literature is made. The tumor was a polypoid mass with a size of 5.5 X 4.0 X 2.8 cm. Histologically, the tumor showed carcinoid and adenocarcinoma with areas of mucous change. Tumor cells containing argyrophil granules were observed in both carcinoidal and adenocarcinomatous areas, but no argentaffin granules were detected in either of the neoplastic areas. Some of the tumor cells had both argyrophil granules and mucin in the same cytoplasm. The electron microscopic study revealed several tumor cells containing neurosecretory granules; however, no clinical signs of hormonal activities of the tumor were observed. The patient died of generalized bone metastases 16 months after surgery. This appears to be the second case of composite tumor of the gallbladder.