Rhabdoid papillary meningioma: a clinicopathologic case series study.

World Health Organization (WHO) grade III meningiomas are subclassified on the basis of their architectural pattern into papillary and rhabdoid subtypes. Some meningiomas even combine papillary architecture with rhabdoid cytology. Additionally, they always show malignant histological features, follow an aggressive clinical course and tend to spread through the CSF after frequent local recurrence. We render the first series of rhabdoid papillary meningioma with review of the literature to further elucidate its biological behavior. From six patients (three male, three female), nine specimens of rhabdoid papillary meningioma were obtained between 1994 and 2010. Correlations of histologic parameters, immunohistochemical study, and clinical features were assessed. The mean age of patients was 44.7 years at their first operation. The mean postoperative follow-up period was 63.2 months. Five patients experienced tumor recurrence, and one of them died from the disease after diffuse leptomeningeal dissemination. The mean time to first recurrence was 28 months. Only one patient was free of tumoral recurrence after an 8-year follow-up. Immunohistochemically, all tumors were positive for vimentin and epithelial membrane antigen. MIB-1 labeling indices were higher following tumor recurrence. The present study expands the clinicopathologic horizon of rhabdoid papillary meningioma and suggests that it will behave aggressively based on its histology and concomitant features of atypia or malignancy or high MIB-1 labeling indices. Close follow-up and aggressive treatments of these tumors are warranted.