Composite lymphoma comprising adult T-cell leukemia/lymphoma and Epstein–Barr virus-positive primary central nervous system lymphoma

A 73-year-old woman presented with cervical lymphadenopathy. A biopsy of the affected lymph node showed the diagnosis of adult T-cell leukemia/lymphoma (ATLL). While treatment was planned, she developed rapid-onset consciousness disturbance and gait disorder 1 week before the initiation of therapy, leading to emergency hospitalization. Computed tomography showed a hypodense lesion in the midbrain, and a cerebrospinal fluid analysis showed ATLL cells, resulting in a diagnosis of central nervous system infiltration of ATLL. High-dose methotrexate plus cytarabine therapy was administered. However, this therapy was ineffective, and the patient died on hospital day 21. An autopsy showed that the midbrain tumor was an Epstein-Barr virus-positive primary central nervous system lymphoma. Although there have been reports of primary central nervous system lymphoma developing during the treatment course of ATLL, to the best of our knowledge, this is the first reported case of concurrent onset of both diseases.