LEPTOMENINGEAL SEEDING WITH ACUTE HYDROCEPHALUS - UNUSUAL CENTRAL-NERVOUS-SYSTEM PRESENTATION DURING CHEMOTHERAPY IN KI-1-POSITIVE ANAPLASTIC LARGE-CELL LYMPHOMA

An unusual central nervous system (CNS) manifestation in a 18-year-old male with Ki-1-positive anaplastic large-cell lymphoma is presented. The diagnosis of Ki-1 lymphoma was first confirmed by the distinct ple omorphic morphology, expression of Ki-l (CD30) antigen on neoplastic c ells and the specific chromosome translocation, t(2;5)(p23;q35). Altho ugh young age is thought to be a good prognostic factor in this diseas e, the course in our patient was very aggressive. At presentation, the re was already extensive extranodal involvement, with malignant cell f ound in the pleural cavity and bone marrow. In spite of rapid shrinkag e of whole-body lymph nodes and a decrease in malignant pleural effusi on soon after starting chemotherapy, headache and vomiting ensued in t he following days. A computerized tomography scan of the brain showed poor corticomedullary differentiation without definite mass lesions, a nd numerous malignant cells were found in the cerebrospinal fluid (CSF ). Although intrathecal methotrexate was given, the patient died follo wing the sudden onset of acute hydrocephalus. CNS involvement in Ki-1 anaplastic large-cell lymphoma is very rare and most cases present as focal mass lesions in the brain parenchyma. Leptomeningeal seeding of the lymphoma cells with acute hydrocephalus contributing directly to d eath has never been reported. The experience from this case suggests t hat CNS involvement may present in variable forms in Ki-1 lymphoma and may be an important cause of mortality in young patients, especially those in advanced stages of the disease. Early detection of CNS involv ement by CSF investigation or even prophylactic CNS therapy may be man datory in these patients.