ACUTE TUMOR LYSIS SYNDROME FOLLOWING INTRATHECAL METHOTREXATE

We report a 17-year-old boy with meningeal involvement of lymphoblasti c lymphoma who experienced acute tumor lysis syndrome following intrat hecal administration of methotrexate. Intrathecally injected methotrex ate provides a slow- release reservoir of methotrexate into the bloods tream with prolonged cytotoxic levels. To the best of our knowledge, t his is the second case of tumor lysis syndrome to be described after i ntrathecal methotrexate injection. The pathogenesis of this unusual co mplication of intrathecal chemotherapy is discussed.