Recurrent Extraventricular Neurocytoma with Malignant Glial Differentiation

ABSTRACT

We present a case of recurrent extraventricular neurocytoma with malignant glial differentiation in left temporoparietal area. A 37-year-old man with presentation of generalized seizure had undergone biopsy of brain tumor in left parietal area in 1987, which revealed extraventricular neurocytoma and radiotherapy was followed. Postoperative course was uneventful until eleven years after biopsy, when he became gradually aphasic and right hemiplegic. Brain CT and MRI revealed enlargement of tumor with peritumoral edema and calcifications. He underwent subtotal tumor removal in 1998. Microscopic examination of second biopsy specimen revealed presence of large areas composed of anaplastic glial cells with frequent mitosis, nuclear pleomorphism, large eosinophilic cytoplasm and eccentric nuclei, resembling gemistocytes, which were strongly immunoreactive to glial fibrillary acidic protein(GFAP) but not to synaptophysin(SNP). Also focal areas of neuronal cells were found, which were immunoreactive to SNP but not to GFAP. These histologic findings imply that this recurred tumor was a high grade, mixed tumor with divergent differentiation of neuronal and astrocyte lineage. We report a rare case of extraventricular cerebral neurocytoma with malignant glial differentiation with review of the literature.