chordoid meningioma

chordoid meningioma

A rare subtype of atypical meningioma (WHO grade 2) which has a greater risk of recurrence than typical (grade 1) meningiomas, but less than malignant (grade 3) meningiomas.
References in periodicals archive ?
Immunohistochemical comparison of chordoma with chondrosarcoma, myxopapillary ependymoma, and chordoid meningioma.
Currently, a chordoid meningioma is considered to be a "meningioma variant consisting predominantly of tissue histologically similar to chordoma.
Within the meningeal neoplasm group, the most unusual cases were the sclerosing meningioma (patient 24; Figure 2, C) and the chordoid meningioma (patient 25; Figure 2, D) invading nerve, although the hemangiopericytoma (Figure 2, E), which had been mistaken for a possible schwannoma (Table), also showed small, neurofilament-positive nerve fibers buried deep with the lesion (patient 26; Figure 2, F).
Both of the invasive meningiomas, that is, the chordoid meningioma and the sclerosing meningioma, are known to be aggressive variants, although currently a WHO grade has not been assigned to sclerosing meningioma.
Some of the more significant changes affecting tumor grade include classifying (1) meningiomas showing central nervous system invasion as grade II rather than grade III, (2) meningiomas with 4 or more mitotic figures per 10 high-power fields (HPFs) as grade II, (3) clear cell and chordoid meningiomas as grade II, (4) papillary and rhabdoid meningiomas as grade III, and (5) tumors with 20 or more mitotic figures per 10 HPFs as grade III.