Acromegaly associated with mixed pituitary adenoma-gangliocytoma and Rathke's cleft cyst.

Gangliocytoma of the pituitary gland is a rare lesion that often occurs in combination with pituitary adenomas and the exact origin is the subject of discussion. We report a rare case of an intrasellar mass of combined gangliocytoma/ pituitary adenoma coexistent with Rathke's cleft cyst. A 50-year-old female was admitted to our hospital with headache, mild acromegaly, and bitemporal hemianopsia. Histologically the tumor was composed of triphasic component of pituitary adenoma, clusters of ganglion cells and small cysts embedded in a variably dense neuropil substrate. Immunohistochemical analysis revealed the ganglion cells and adenoma cells were positive for synaptophysin and neurofilament. The lining of Rathke's cleft cyst was immunoreactive for cytokeratin 8. The exact pathogenesis of combined sellar pathology is not clear yet. However, a common stem/progenitor cell origin of both the adenomatous and neuronal component of these lesions has been suggested.