AN INSTRUCTIVE FALSE DIAGNOSIS - STEROID-INDUCED COMPLETE REMISSION OF A CNS TUMOR - PROBABLY LYMPHOMA

In recent years the incidence of primary cerebral lymphomas has increa sed. Diagnosis by imaging techniques (CCT, angiography, MRT) and stere otactic biopsy are considered as reliable diagnostic tools. Therapeuti cally a combination of radio-, steroid- and chemotherapy is recommende d. We report a case of space-occupying CNS lesion in which the radiopa que enhancing process completely disappeared after biopsy and steroid therapy. A year later the tumor recurred on the other side and again r egressed after steroid therapy. The first biopsy showed signs of a pap illar tumor, so a choroid plexus papilloma was suspected. On examinati on of the treatment history however, this diagnosis had to be revised. A primary CNS lymphoma seems most probable. The phenomenon of a tumor remission under steroid administration and the problems related to th e differential diagnosis are discussed.