Medulloblastoma: survey of factors possibly influencing the prognosis.

In a series of 310 cases the role of the factors age, sex, location of the tumour (midline or lateral), and medulloblastoma type (classic or desmoplastic) were analysed with regard to the prognosis. The influence of therapy is not considered because of the inhomogeneity of the material and the view nowadays that treatment is insufficient. The occurrence of lateral (or hemispheric) medulloblastomas increases in the group of the 11-15 years old patients. The proportion of the desmoplastic type is greater in adults than in children, but they are distributed almost equally medially and laterally. There seems to be no definite correlation between sex and the survival time. The mean survival time increases with age. With regard to the histological subclassification into children and adults, the mean survival times are nearly identical. The only obvious factor with a decisive influence on the prognosis seems to be the time of appearance of the tumour. Additionally, the data support the conclusion that a desmoplastic medulloblastoma should be considered as a histological variant without clinical relevance.