[Localized polyarteritis nodosa presenting as epididymal mass: a case report].

A 31-year-old man was admitted with a mass in the left scrotum. On palpation, the mass was elastic hard and hen's egg-sized. It was impossible to discriminate between testis and epididymis. Left high orchiectomy was performed under the diagnosis of left testicular tumor. Histopathologically, distinct arteritis was demonstrated in the epididymis. Since the patient showed no evidence of systemic disease or serological abnormalities, he was diagnosed to have localized polyarteritis nodosa.