Expression of O⁶-methylguanine DNA methyltransferase (MGMT) and immunohistochemical analysis of 12 pineal parenchymal tumors.

Pineal parenchymal tumors (PPTs) are rare neoplasms which occupy less than 1% of primary CNS tumors. Because of their rare incidence, previous reports on PPTs are limited in number and the useful molecular markers for deciding histological grading and even selecting chemotherapy are undetermined. In this study, we conducted immunohistochemical analysis of 12 PPT specimens, especially for expression of O⁶-methylguanine DNA methyltransferase (MGMT) to assess whether temozolomide (TMZ) could serve as a possible alternative therapy for PPTs.