Pathologic features of nerve sheath tumors with respect to prognostic signs

Clinicopathologic evaluation of primary and recurrent nerve sheath tumors was performed for 87 fully documented cases treated in the National Oncological Institute (Budapest) between 1955 and 1976. Morphologic features of all tumors, i.e., of both nonrecurring and recurring tumors with and without malignant transformation, were evaluated according to a uniform scoring system. Scores of the primary tumors showed good correlation with their further course; in case of recurring tumors, the scores permitted some conclusions regarding their expectable behavior. Neurofibromas and neurinomas displayed similar courses, but the clinical courses of typical and cellular tumors were not the same. Cellular tumors with high scores were more disposed to recur and undergo malignant transformation. Recurrences in cases of late malignant transformation were more frequent than in those showing no transformation.