Recurrent polyarteritis nodosa limited to the testis.

A 40-year-old man presented with acute scrotum. He was afebrile and had no other symptoms. Color Doppler sonography of the scrotum was performed at 24 hours after the onset of pain and demonstrated avascularity of the left testis. The right testis was normal. Under the diagnosis of testicular torsion the left testis was excised. Histopathological examination revealed testicular vasculitis (fig. 1). The patient was subsequently evaluated for evidence of systemic disease. Laboratory tests, including complete blood count, erythrocyte sedimentation rate, liver and renal function tests, C-reactive protein, complement levels, antineutrophil cytoplasmic antibodies and hepatitis B surface antigen, were normal except for increased antinuclear antibody (titer 1:320, diffuse pattern). However, findings on examination were unremarkable and the diagnosis was PAN isolated to the left testis. After surgery no treatment was offered. The patient remained well with no clinical evidence of disease activity until 16 months after diagnosis, when sudden pain developed in the right scrotum. Sonography of the scrotum was performed at 48 hours after onset and showed avascularity of the right testis. Acute scrotum was diagnosed and emergency exploration was performed. An old blood clot was contained within the tunica albuginea without bleeding, so the right testis was excised. Microscopic examination demonstrated recurrent vasculitis (fig. 2). Autoimmune markers were normal except for increased antinuclear antibody (titer 1:160), so the patient was discharged home without additional treatment. A regimen of intramuscular injections of testosterone was started. At 22-month followup the patient had no signs of systemic PAN. DISCUSSION