Distinctions between pituicytoma and ordinary pilocytic astrocytoma. Case report.

The authors present a rare case of pituicytoma. A dynamic magnetic resonance study performed after Gd injection revealed a markedly, homogeneously enhanced, early-phase pituitary lesion in a 32-year-old woman with a 1-year history of amenorrhea. The tumor bled easily during transsphenoidal resection. The lesion consisted of plump spindle cells and lacked Rosenthal fibers and granular bodies, and thus was different from ordinary pilocytic astrocytoma or any other form of this tumor. Although pituicytoma is often confused with pilocytic astrocytoma when it appears in the sellar region, these two kinds of gliomas should be distinguished on the basis of histological differences.