Pleomorphic xanthoastrocytoma arising from the suprasellar region: A report of two cases.

Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic neoplasm that usually arises in children and young adults. Typically, lesions of PXA are superficially located in the cerebral hemispheres. Herein, we report two extremely rare patients with PXA arising from suprasellar regions. One of the patients is a 29-year-old man admitted to our hospital with a history of progressive headache for 1month. The patient's brain MRI revealed a large tumor arising from the suprasellar cistern of the third ventricle. The second patient, a 52-year-old woman, presented with progressive dizziness and visual disturbance that had developed over the course of 1year. The MRI revealed a well-enhanced suprasellar solid mass measuring 1.4×1.2×1.4cm. Both patients underwent surgical removal of their tumors, and both patients showed similar microscopic structures and immunohistochemical phenotypes: the tumor cells were pleomorphic with mixtures of spindle-shaped, and multinuclear giant cells. In addition, eosinophilic granular bodies and xanthomatous cells were seen on section. Immunohistochemistry was positive for GFAP, S-100, and CD34, and was negative for IDH 1, CK, and Syn. The Ki-67 proliferation index was less than 1%. Silver impregnation revealed reticulin fibers surrounding the individual tumor cells, and small cell groups. Based on these findings, the two patients were diagnosed with PXA in the suprasellar region. To date, only five such patients have been reported in the literature. PXA should be included in the differential diagnosis for tumors arising in the sellar region.