The separation of pineocytoma from pineoblastoma

Abstract

From our study of eight pineoblastomas and five pineocytomas and a review of the literature, we have described two clinicopathologic syndromes that characterize these neoplasms. Pineoblastomas highly resemble the medulloblastoma-neuroblastoma group of tumors and occur mostly in young people. The tempo of progression of the disease is fast, the length of illness is short. These are infiltrating neoplasms that commonly spread via the cerebrospinal fluid. They are radiosensitive. Histologically they are also similar to the medulloblastoma-neuroblastoma group and are characterized by the scarcity of cytoplasmic processes and by the Homer Wright rosette. They contain giant cells. Pineocytomas are tumors of adults. The tempo of progression of the disease is slow, and the length of illness is long. They expand by compressing the surrounding tissues. Histologically they are characterized by the abundance of cytoplasmic processes and by the pineocytomatous rosette. They contain giant cells. Areas composed of neoplastic gangliocytes and astrocytes in various combinations are common variants in some of these neoplasms.

Management and Survival of Pineoblastoma: An Analysis of 34 Adults From the Brain Tumor Registry of Japan

“…Mitosis are found along with Homer-Wright rosettes, Flexner-Wintersteiner rosettes, and areas of necrosis. 3,33) More recently, Schild et al 33) has divided pineal parenchymal tumors into four types: pineocytomas, intermediate tumors, mixed tumors, and pineoblastomas. The intermediate tumor is described as a transitional form between pineocytomas and pineoblastomas.…”

“…Two patients (5.9%) were asymptomatic at the time of diagnosis. The median tumor diameter was 2 cm (range 1-À8 cm), corresponding to a median volume of 4.2 cm 3 (range 0.5-382 cm 3 ). Only 30 patients had definite data documenting the presence (6 patients) or absence (24 patients) of spinal dissemination.…”

“…3,33) A two-tiered staging system distinguishes pineoblastomas from pineocytomas. The pineocytoma is a well-circumscribed tumor that grossly compresses the surrounding tissue.…”

“…These grading scales are relatively recent descriptions, and most series of pineal parenchymal tumors have used the two-tiered grading system. 3,20) Pineoblastomas are rare tumors that are sometimes simply described as supratentorial primitive neuroectodermal tumors (PNETs). 20,31) Pineoblastomas and cerebellar medulloblastomas both share the presence of Homer-Wright rosettes, which are widely accepted to represent abortive attempts at neuroblastic differentiation.…”

“…20) In addition, mononucleated and multinucleated tumor giant cells are present in pineoblastomas as in cerebellar medulloblastomas. 3) Hence, the category of PNETs has been said to include both cerebellar medulloblastomas and pineoblastomas.…”