Central neurocytomas express photoreceptor differentiation

BACKGROUND. Central neurocytomas are composed of mature neuronal elements, frequently arranged in rosettes similar to those present in pineocytomas. T his suggests the possibility of similar patterns of differentiation, includ ing photoreceptor differentiation. The authors analyzed the immunoreactivit y of central neurocytomas for retinal S-antigen, neuronal, glial, and neuro endocrine markers. METHODS. Thirty-three central neurocytomas were analyzed with reference to their clinicopathologic characteristics, immunoreactivity, and the possibil ity that anaplastic histologic features correlated with aggressive clinical behavior. RESULTS. There were 18 male and 15 female patients. The median age at diagn osis was 30 years (range, 3-69 years). All of the tumors with specified loc ation were related to the ventricles. Thirty-two tumors were diagnosed at s urgery and 1 at autopsy. Histologic features included mineralization (20 of 33), foci of necrosis (4 of 33), chronic inflammation (4 of 33), ganglion cell differentiation (1 of 33), and lipomatous differentiation (1 of 33). N one of the lesions had significant nuclear pleomorphism, mitotic activity, or vascular endothelial proliferation. Immunohistochemistry included expres sion of synaptophysin (33 of 33), neuron specific enolase (31 of 33), S-100 protein (25 of 33), retinal S-antigen (14 of 24), somatostatin (8 of 27), glial fibrillary acidic protein (4 of 33), neurofilament protein (3 of 22), and leucine enkephalin (1 of 27). At follow-up, 15 of 23 patients were ali ve an average of 8.1 years (range, 0.91-35.9 years) after surgery. CONCLUSIONS. Central neurocytomas behave as slowly growing neoplasms that r emain confined within one or several supratentorial ventricles and are asso ciated with long survival after surgical excision. Malignant forms with agg ressive clinical behavior were not found. The neoplastic cells can express photoreceptor differentiation possibly relating central neurocytomas to pin eocytomas. Adipocyte differentiation may be present, and the possibility of a relation between the central neurocytoma and cerebellar liponeurocytoma should be entertained. Cancer 2001; 91:136-43. Published 2001 by the Americ an Cancer Society*.