Pituicytoma: Report of two cases.

This report describes two cases of pituicytoma. The two patients were female and presented with visual complaints, diabetes insipidus, headaches and menstrual disorders. The imaging characteristic was an intrasellar or suprasellar mass, and one mass originated in the pituitary stalk. The mass showed homogeneous enhancement with contrast administration. A hematoxylin and eosin stain showed a compact structure consisting of elongated, bipolar spindle cells arranged in interlacing fascicles or assuming a storiform pattern. Immunohistochemically, the tumor showed diffuse strong expression of S-100 protein, vimentin and epithelial membrane antigen, and glial fibrillary acidic protein was focally positive. The pituicytoma may have originated in the pituitary stalk and presented with diabetes insipidus, and the differential diagnosis should be compared with the pituitary stalk mass. Bleeding during resection was moderate, and surgery was regarded as the first choice of treatment for pituicytomas.