TUMORS OF PINEAL PARENCHYMAL-CELLS - A CORRELATION OF HISTOLOGICAL FEATURES, INCLUDING NUCLEOLAR ORGANIZER REGIONS, WITH SURVIVAL IN 35 CASES

We studied 35 parenchymal neoplasms arising in the pineal gland, inclu ding 11 pineoblastomas, 21 pineocytomas, and three mixed pineocytoma-p ineoblastomas. Pineoblastomas were most commonly found in children (me an age, 12.6 years). The median postsurgical length of survival for se ven patients, including five with remote metastases, with fatal outcom e was 24 months. The 21 pineocytomas were found in older individuals ( mean age, 26.8 years). Four patients with pineocytoma died; two before surgery and two in the immediate postoperative period. The remaining 17 patients survived for intervals between 6 and 118 months after surg ery. Two mixed pineocytoma-pineoblastomas were found in infants who di ed a few months after biopsy, whereas a third patient, an adult, was a live at 46 months after excision and irradiation. Both pineoblastoma a nd pineocytoma exhibited variable immunoreactivity to neurofilament pr oteins, synaptophysin, glial fibrillary acidic protein, S-100 protein, retinal-S antigen, and rhodopsin; the highest percentages of positive cells stained with synaptophysin. Three pineocytomas exhibited gangli onic differentiation and two of them also showed a glial component. Pr ognosis could not he correlated with the degree of divergent different iation. Comparison of silver-stained nucleolar organizer region (AgNOR ) counts between pineoblastomas and pineocytomas suggests that the for mer are more actively proliferative than the latter, with mixed pineoc ytoma-pineoblastoma showing intermediate activity. There was no correl ation between AgNOR score and prognosis within the three tumor groups. HUM PATHOL 26:20-30. Copyright (C) 1995 by W.B. Saunders Company