Primary intracranial myopericytoma: report of three cases and review of the literature.

Myopericytoma is a benign tumour generally arising in the subcutaneous and superficial soft tissues of the extremities. Very few cases have been reported in other locations and intracranial examples are exceptional. We now report on three cases of primary intracranial myopericytoma and review the literature on that rare entity. The patients were women in their fifties who presented with decreased visual acuity in two cases and raised intracranial pressure in one case. The tumour involved, respectively, the anterior cranial fossa, the orbital apex and the pineal region. Gross total resection was achieved in all three cases. Histological analysis revealed oval-to-spindle shaped myoid-appearing cells with a striking tendency for concentric perivascular growth. The lesional cells showed apparent differentiation towards perivascular myoid cells as witnessed by smooth muscle actin expression. In one case, an epithelioid differentiation was also present. None of the patients received adjuvant therapy. One patient died of unrelated causes 6 months after surgery. The other two are alive and well at 9 and 12 month follow-up respectively. Myopericytoma is a recently described neoplasm, and it is likely that reappraisal of intracranial haemangiopericytoma with which it shares many histopathologic features will lead to more case reports of primary intracranial myopericytoma.