[A patient with intravascular malignant lymphomatosis presenting subacute dementia one year after sustained urinary retention and high serum LDH activity from the onset].

We report a 71-year-old man with intravascular malignant lymphomatosis who showed high serum LDH and urinary disturbance for one year before manifesting dementia. High serum LDH was found at a health check at age 70. Two months later, he had an onset of backache and urinary retention. MRI of the spinal cord was unremarkable. One year later, he showed decline of mental activities and was admitted to our hospital. He was agitated and confused. However cranial nerve palsy or limb weakness was not noted. The MRI of the brain showed T2-high signal in bilateral occipital, right temporal lobe and the left insular cortices. The abdominal CT scan showed swelling of the adrenals on both sides. Adrenal biopsy revealed diffuse large B cell lymphoma. He developed respiratory distress and he died two months after the admission. Post mortem examination revealed intravascular and extravascular proliferation of lymphoma cells in most of the internal organs including adrenals, spleen, liver and the kidneys. In the brain, the laminar necrosis was seen in the left occipital cortex and hemorrhagic infarctions were noted in the insular and temporal cortices and the medial temporal cortex. Sacral spinal cord showed necrosis of the gray matters and loss of myelinated fibers in the white matter. Intravascular proliferation of the lymphoma cells were also seen in the vessels of the brain and the spinal cord. This patient suggests the importance of survey for intravascular malignant lymphomatosis, when high serum LDH and myelopathy of lumbosacral area are seen.