Correlation of p63 immunoreactivity with tumor grade in meningiomas.

Predicting tumor behavior in meningiomas based on morphologic features alone remains difficult. The present study was undertaken to assess the correlation between p63 expression and histological grade of meningiomas. A total of 37 archival intracranial meningiomas were classified into 20 grade I, 13 grade II, and 4 grade III meningiomas. Using immunohistochemical methods, staining was scored based on nuclear and/or cytoplasmic distribution as follows: 0, no staining; 1, 50% or less of the cells; 2, more than 50% of the cells. Of grade I meningiomas, 95% (19/20) lacked nuclear p63 expression and none exhibited cytoplasmic staining. Overall, 92% of grade II tumors showed nuclear expression and 31% (4/13) showed cytoplasmic expression. Grade III tumors showed an overall nuclear expression of 75% (3/4) with all exhibiting cytoplasmic staining. Our results indicate a good correlation exists between histological grade and p63 protein expression, suggesting that p63 expression might be correlated with the clinical outcome.