[A case of nonsystemic vasculitic neuropathy with anti-neutrophil cytoplasm antibody (ANCA)].

A 26-year-old woman with mononeuropathy multiplex complained of severe pain of right foot and ipsilateral steppage gait. Careful examination failed detect evidence of systemic lesions. Sural nerve biopsy revealed myelin ovoids and loss of myelinated fibers, which were different in severity among the fascicles. There were mild mononuclear cell infiltrations around arterioles in the epineurium. A diagnosis of nonsystemic vasculitic neuropathy (NSN) was made. Anti-neutrophil cytoplasm antibody (ANCA), a specific marker for microscopic polyarteritis nodosa and Wegener's granulomatosis, was positive in the patient. Oral administration of prednisolone ameliorated the sensorimotor disturbances, and ANCA turned to be negative. This is the first report of a patient with NSN showing positive ANCA.