Crush preparations of meningiomas: can grading be accomplished?

Overview

Crush preparations (CP) for the diagnosis of meningioma are routinely performed in the frozen section suite when tissue is submitted for intraoperative consultation. The goal of this study was to examine the cytologic features of meningiomas in CP and evaluate if benign meningioma (Grade 1), atypical meningioma (Grade 2), and malignant meningioma (Grade 3) can be diagnosed on CP. All cases of meningioma (1999-2007), which were submitted for frozen section at our institution, were retrospectively reviewed. These cases were examined intraoperatively by frozen section and CP. The final histologic diagnosis was taken as the gold standard. A total of 107 meningiomas cases were reviewed. The cytological features of all these cases were studied, and features such as pleomorphism, hemorrhage, necrosis, mitosis, and presence or absence of nucleoli were recorded. Using the final histopathologic diagnosis as the gold standard, there were 72 (Grade 1), 22 (Grade 2), and 13 (Grade 3) meningioma cases, which were studied. In conclusion, this study reviews the salient cytologic features of Grades 1-3 meningiomas. It demonstrates that it is difficult to separate Grade 1 from Grade-2 meningioma on CP, and last, Grade-3 meningioma can be easily diagnosed on CP.