Abstract: Objective To investigate the clinical characteristics and treatments of pineal parenchymal tumors of intermediate differentiation(PPTID). Methods Data of 6 cases of PPTID admitted to the Department of Neurosurgery from June 2009 to July 2010 were analyzed. The statistical data include clinical features, radiological, pathological characteristics and treatments. Among the six cases, one case underwent transcranial biopsy, five cases underwent transfrontal-interforniceal approach for tumor resection, five patients received gamma-knife, four patients received radiotherapy and four patients received chemotherapy. Results The whole neuraxis disseminating of the tumor were found in four cases. Among the six cases, one tumor was totally removed; three with subtotal removal and one with partially removal, one case performed biopsy. The symptoms were improved in two patients after radiation, two patients after gamma-knife, and three patients after chemotherapy. Conclusion PPTIDs are liable to disseminate through the central nervous system. Multiple treatments are needed for PPTIDs, the tumors should be resected totally as far as possible and the postoperative radiotherapy or chemotherapy are necessary for this entity.

Key words: pineal parenchymal tumors of intermediate differentiation, neuraxis dissemination, operation, chemotherapy, radiation