Bilateral basal ganglia lesions as initial manifestation of CNS invasion in adult T-cell leukemia.

We describe the case of a 67-year-old man who exhibited unsteadiness in walking, topographical disorientation, and urinary incontinence. Neurological examination revealed somnolence and mild weakness in the lower limbs with slight rigidity in the upper limbs. Cerebrospinal fluid examination showed pleocytosis with "flower cells" and an extremely high level of soluble interleukin-2 receptor. T2-weighted brain imaging revealed symmetrical high-intensity lesions in the bilateral caudate putamen. Positron emission tomography demonstrated intense uptake of 2-[fluorine-18]-fluoro-2-deoxy-d-glucose in the same region. He was diagnosed with central nervous system invasion by adult T-cell leukemia (ATL) and received chemotherapy. Interestingly, chemotherapy ameliorated the lesions and terminally caused the gray matter itself to atrophy in the bilateral caudate nuclei, which may be evidence for the direct infiltration of ATL tumors.