[Neurofibroma-associated left peroneal nerve palsy in a patient with acute lymphoblastic leukemia].

Peroneal nerve palsy developed in a patient with T cell-type acute lymphoblastic leukemia (ALL) is reported. In the fifth month after starting of chemotherapy against ALL, the patient, a 7-year-old girl, developed drop foot on the left. Three possibilities were considered as its pathogenesis; (1) VCR neuropathy, (2) neurotoxicity of intrathecal MTX, (3) leukemic invasion to the spinal canal. However, there was no evidence of leukemic invasion in any lumbar taps, and no improvement was obtained by cessation of VCR and intrathecal MTX. Examination by CT scan revealed tumors in the intervertebral (L5-S2) region, which was diagnosed to be neurofibromas by biopsy. The tumors compressed the left peroneal nerve and neurotoxicity of antineoplastic agents for ALL could be the cause of her drop foot.