Two cases of toxoplasmic encephalitis in patients with acute T-cell leukaemia and lymphoma.

Two cases of opportunistic cerebral infections in HIV-negative cancer patients due to chemotherapy induced immunosuppression are reported. A 61-year-old patient with low grade lymphoma (immunocytoma as referred to the Kiel classification) developed stereotactical biopsy proven toxoplasmic encephalitis 6 months after initiation of fludarabine treatment. The lymphoma had been diagnosed 8 years earlier and had been treated with several different regimens. In the second case, a 55-year-old patient developed neurological symptoms while in complete remission from acute T-cell leukaemia. The patient had been treated with a multidrug chemotherapy regimen including radiotherapy of the brain and intrathecal chemotherapy. When toxoplasmic encephalitis was bioptically diagnosed the patient was on maintenance chemotherapy with methotrexate and mercaptopurine for 12 months. The patients' characteristics and outcome are reported and the potential pathogenesis is discussed.