Folliculostellate cell tumor in pituitary gland.

A 33-year-old woman presented with visual field defects. Magnetic resonance imaging demonstrated a pituitary tumor with suprasellar extension. The tumor was partially removed by trans-sphenoidal surgery. Histologically, the tumor was composed of fascicles of spindle cells which were immunohistochemically positive for S-100 protein, Galectin-3, vimentin and EMA. Based on the morphology and immunostaining pattern, diagnosis of folliculostellate cell tumor in the pituitary gland was given.