Small cell carcinoma of the gall-bladder with intestinal metaplastic epithelium.

A case of small cell carcinoma of the gall-bladder is described. Immunohistochemically, the tumor cells were positive for chromogranin A, synaptophysin and neuronspecific enolase, which suggests that they derived from neuroendocrine cells. The overlying and surrounding epithelium of the tumor showed intestinal metaplasia including goblet cells, pseudopyloric glands, Paneth's cells, and chromogranin A and synaptophysin-positive endocrine cells. Definite adenocarcinoma was absent. The endocrine cells in the epithelium were more numerous in the vicinity of the tumor. The present case supports the supposition that endocrine cell tumor (including small cell carcinoma) of the gall-bladder may develop from endocrine cells of the intestinal metaplastic lesion.