PRIMARY KI-1-POSITIVE T-CELL LYMPHOMA OF THE BRAIN - AN AGGRESSIVE SUBTYPE OF LYMPHOMA - CASE-REPORT AND REVIEW OF THE LITERATURE

BACKGROUND By detection of the Ki-1 antigen, Stein (1985) defined a ne w entity of anaplastic large cell lymphoma [24]. Apart from our case, only four further cases of Ki-1 positive primary central nervous syste m lymphoma (PCNSL) have been reported in the literature to date. CASE REPORT A 63-year-old man presented with two frontal and parietal mass lesions and one ring lesion on computed tomography scan. Clinically, n o evidence of brain metastases or abscesses could be found. Immunohist ochemical investigations of biopsy specimens revealed a large cell ana plastic T-cell lymphoma positive to Ki-1 antigen. In spite of ail ther apeutic efforts, the patient died less than 3 months after the onset o f symptoms. DISCUSSION In all cases the clinical course was very rapid , suggesting that Ki-1 positive PCNSL might form an aggressive subtype of lymphomas. Since the radiologic appearance was atypical and clinic al diagnosis was not possible, diagnostic biopsy for immunohistochemic al diagnosis should be performed.