[An autopsied case of paraneoplastic neurologic syndrome (limbic encephalitis, cerebellar degeneration, and pseudohypertrophy in the inferior olivary nuclei) associated with T cell lymphoma].

We describe a patient with paraneoplastic neurologic syndrome confirmed on postmortem examination. This 42-year-old man was admitted due to general fatigue, emaciation and acute-onset disorientation. Neurological examination revealed disorientation, moderate cognitive impairment, cerebellar ataxia, bilateral limitations and nystagmus in all directions during external ocular movement, swallowing disorder, bilateral Babinski sign, sensory disturbance in the distal parts of all extremities, and Romberg's sign. T-cell lymphoma was diagnosed following biopsy of the cervical lymph node. Neurological condition improved slightly after chemotherapy, but subsequently deteriorated. At about 6 years after the disease onset, brain magnetic resonance imaging (MRI) revealed atrophy of bilateral hippocampi and the upper vermis of the cerebellum. The patient died of pneumonia after a clinical course of about 6 years and 6 months. Pathologically, neuronal loss, reactive gliosis and perivascular lymphocytic infiltration were observed in the hippocampi, cerebellum, and inferior olivary nuclei. Lymphocytes around the vessels were positive for LCA and UCHL-1, but negative for CD8 and L26, and thus were considered to be T cells. No lymphoma cell was observed in the central nervous system or lymphatic organs. Based on the pathological findings, paraneoplastic neurologic syndrome (limbic encephalitis, cerebellar degeneration and olivary pseudohypertrophy) associated with T-cell type malignant lymphoma was diagnosed. Only three other cases of paraneoplastic neurologic syndrome associated with T-cell lymphoma have been reported. In those cases, death occurred due to the deterioration of malignant lymphoma, whereas the present patient died about 6 years after the remission of malignant lymphoma. Prognosis may thus depend on the course of the malignant lymphoma. In the present patient, neurological symptoms deteriorated after remission of malignant lymphoma, and no pathological lesion were found in the lymphatic organs. Lesions in the central nervous system in paraneoplastic neurological syndromes may follow a course independent of the original malignant disease.