[A Case of Polyarteritis Nodosa Diagnosed from Pathological Findings of Refractory Epididymitis].

A 54-year-old man was admitted to internal medicine due to unidentified fever persisting for 3 months, and was examined. Then, he was referred to our department for suspected pyelonephritis. Although he was initially being treated for pyelonephritis, right epididymitis occurred during the course of treatment. Antibiotics were ineffective, and symptoms such as weakness and subctaneous nodules also appeared. We performed epididymectomy to differentiate this intractable epididymitis from other systemic diseases. Pathological findings were fibrinoid necrotic vasculitis of middle and small arteries. Of the diagnostic criteria for polyarteritis nodosa, 4 major symptoms and histological findings were satisfied. After we started oral administration of predonin, the fever went down and the creative protein level decreased immediatately.