Chordoid Meningioma - A Case Report: Clinicopathological Features and Differential Diagnosis of an Uncommon Tumor.

Meningiomas are tumors that originate from the arachnoid cell and the majority are benign and grade I tumors according to World Health Organization. Chordoid meningioma is an uncommon variant of meningioma and corresponds to grade II tumor in the World Health Organization Classification of Tumors of the Nervous System 2007 because of its more aggressive behavior and increased likelihood of recurrence. A 75-year-old female was referred to the neurosurgery department complaining of headache, syncope, and seizure. Radiological examination revealed a mass lesion in the neighbourhood of the frontal lobe that destructed bone and was associated with peritumoral edema. The patient underwent surgery. The tumor was totally excised with the dura beneath. Histopathological examination showed that the tumor was composed of clusters and cords of small polygonal cells with fine chromatin and eosinophilic vacuolated cytoplasm embedded in a myxoid matrix, and also focal whorls of spindle-shaped cells. Two mitoses were seen in 10 high power fields. Vascular proliferation was observed in some tumoral areas. Bone invasion was present. Immunohistochemical analysis of the tumor cells revealed widespread strong membranous and cytoplasmic expression of epithelial membrane antigen. The Ki67 labeling index was 6-8%. All of these findings were consistent with a diagnosis of chordoid meningioma, the neoplasm was identified as grade II based on the World Health Organization Classification, 2007. In this report we present a case of chordoid meningioma without classical radiological findings of meningioma with areas of vascular proliferation that mimicked glial tumors at histopathologic examination.