Malignant fibrous histiocytoma of scalp with intracranial invasion 20 years after postoperative irradiation.

We report a case of malignant fibrous histiocytoma with intracranial invasion occurring 20 years after radiation therapy for astrocytoma. Magnetic resonance imaging suggested that a dumbbell-shaped tumor arising from soft tissue was pressing the brain. Histopathological findings revealed a storiform pattern with spindle cells such as fibroblasts, histiocytes, epithelioid cells with irregularly shaped nuclei, and bizarre giant cells. Three operations involving craniectomy were necessary because of recurrence.