Giant cell type of primary intracranial malignant fibrous histiocytoma: a case report.

The primary intracranial giant cell type of malignant fibrous histiocytoma (GC-MFH) is rare, and the resemblance to meningioma causes diagnostic confusion. Discrimination from meningioma bears important therapeutic and prognostic implications. We report one such case in which an extracranial malignant neoplasm was seen after the initial diagnosis and treatment. A 62-year-old woman presented with history of seizure. MRI revealed a huge right frontotemporal, homogeneously enhanced extraaxial lesion with significant mass effect. The main vascular supply was the middle meningeal artery. Workup for lesions elsewhere was negative. Gross total resection including dural attachment was achieved. The histopathological features were consistent with the diagnosis of GC-MFH. Immunohistochemistry disclosed varied reactivity profiles in tumor component cells: the spindle-shaped cells possessed features of mesenchymal and hematopoietic lineage, the histiocytic cells those of mesenchymal and epithelial cells, and the osteoclast-like multinucleated giant cells those of monocyte/macrophage and epithelial cells. Proliferative activity was absent in giant cells. Local irradiation of 60 Gy (linac) was performed. The patient did well for 10 months, and follow-up MRI showed no evidence of tumor recurrence. Subsequently, she developed ascites and died 3 months later as a consequence of end-stage adenocarcinoma (ovary) with peritoneal dissemination. There is no established treatment protocol for primary intracranial MFH. Although gross total resection and local irradiation were effective in the short-term control of local relapse in the present case, occurrence of extracranial neoplasm was fatal. Close follow-up aimed at early detection of local recurrence and distant metastases, as well as extracranial malignancy, remains important.