The histopathological and clinical relevance of apoptotic cell death in medulloblastomas.

We studied apoptosis in 40 medulloblastomas by in situ end labeling (ISEL) of DNA strand breaks. In situ end labeling was performed on paraffin-embedded material from classical and desmoplastic medulloblastomas and medulloblastomas with glial and combined differentiation. The number of labeled apoptotic cells varied considerably from tumor to tumor as well as between different areas in the same tumor. However, there was no significant difference in the averaged numbers or in the pattern of apoptotic tumor cells between the different differentiations of medulloblastoma. Unlabeled tumor cells displaying features of apoptosis were found in small numbers, indicating that tumor cells may also be able to undergo cell death different from classical apoptosis. A significantly higher number of apoptotic tumor cells in male patients could be demonstrated corresponding to the reported difference in survival rates between male and female patients suffering from medulloblastoma. A clear cut trend of a negative relation between apoptosis and age by operation was found.