MACROSCOPIC DESCRIPTION: A rubbery ovoid pink nodule 15x8x8mm and six pale tan fragments 2-10mm. Multiple TS through large nodule.
MICROSCOPIC DESCRIPTION: The sections show somewhat lobulated fragments of moderately cellular glial tumor. The tumor cells show prominent clustering. They have round to ovoid nuclei with no significant nuclear pleomorphism. There is microcystic change in the background. No mitoses, endothelial cell hyperplasia or necrosis is identified. No evidence of metastatic carcinoma is seen. The features are those of a subependymoma.
DIAGNOSIS: Right frontal horn tumor: Subependymoma (WHO Grade I).