Pituitary adenoma with neuronal choristoma: a report of two rare cases.

Two rare cases of pituitary adenoma with neuronal choristoma are described. Both patients were female and presented with features of acromegaly with elevated growth hormone and prolactin levels. Radiologically, both lesions were predominantly intrasellar in location with extension into suprasellar region, but hypothalamus was not involved. Histopathological examination revealed a mixture of chromophobe pituitary adenoma cells and neuronal cells. In both cases, the adenoma component was positive for growth hormone and prolactin. Interestingly, immunopositivity for alpha-subunit, cytokeratin and prolactin was seen in the adenoma and neuronal cells in one case. Our findings support the hypothesis that the neuronal cells possibly arise from adenoma cells as a result of metaplasia.