Immunohistochemical expression of cyclooxygenase-2 (COX-2) is not associated with tumor grade in feline meningiomas

Meningioma is the most common primary brain tumor in cats and occurs less frequently in the spinal cord. This study aimed to investigate cyclooxygenase-2 (COX-2) expression in feline meningiomas, and the possible association between COX-2 immunoreactivity and tumor grade using eight low-grade and seven high-grade meningiomas. All tumors (n = 15/15) were immunoreactive to COX-2. The expression of COX-2 was not significantly correlated with tumor grade (P = 0.22 and 0.34 for staining and intensity, respectively) but was significantly associated with necrosis (P = 0.04 and 0.01 for staining and intensity, respectively). The findings in this study suggest that feline meningiomas express COX-2, but there were no differences in COX-2 immunoreactivity patterns between low- and high-grade meningiomas. However, the association between COX-2 expression and the presence of necrosis indicates a potential area for therapeutic intervention with selective COX-2 inhibitors.