Chordoid meningioma: a clinico-pathological study of an uncommon variant of meningioma.

Chordoid meningioma is a rare variant of meningioma, with a higher incidence in the young and a supposed association with Castleman's syndrome. They have an aggressive clinical course, and are assigned as WHO grade II meningiomas. To the best of our knowledge, 284 chordoid meningiomas have been reported in the literature. This series reporting 33 cases is the third largest series in published literature from a single Institution. We reviewed Clinico-pathological characteristics of 33 patients diagnosed with chordoid meningioma between 2001 and 2015 in our institution. Forty-one specimens were available for review of histopathological and immunohistochemical characteristics. There were 15 men and 18 women with mean age of 36.8 years (median 36 years, range 9-62 years) at diagnosis with three cases occurring in pediatric age group. The majority were supratentorial in location with 11 convexity, 1 falcine, 5 parasagittal, 1 intraventricular, skull base involvement in 12 with 4 being petroclival location and 3 had spinal lesions. Lymphoplasmacytic infiltrates were seen in 23 cases with majority being T cells. MIB index varied from 1 to 14%. Five patients received radiotherapy for residual lesion. Two patients died (recurrence-1, post-operative complication-1). Three patients were lost to follow up after surgery. The mean post-operative follow up period for the remaining was 55.3 months. Seven patients had recurrence of which three had it twice. This study adds to the pool of available data for better understanding of this variant of meningioma. These meningiomas occur in middle age; spinal lesions and pediatric cases are not uncommon. We did not find any association between surgery, post-operative radiotherapy and histopathological features with recurrence and survival. Small number of cases may be responsible for this statistical insignificance.