Case Presentation: A 19 year-old man presented with two days of non-radiating left testicular pain. He denied associated symptoms or trauma. His past medical and surgical histories were unremarkable. He denied sexual activity and denied use of drugs or alcohol. Family history was negative for rheumatologic conditions and malignancy. Vital signs were normal. He had left testicular swelling and left testicular and inguinal tenderness. The remainder of his exam was normal. Basic laboratory data were normal including: urinalysis with culture, ESR, α-fetoprotein, and β-HCG. Ultrasound of the scrotum showed a wedged-shaped, hypo-echoic area without flow on Doppler representing segmental infarction versus testicular mass. Pelvic CT showed enlarged para-aortic lymph nodes representing reactive changes versus metastatic disease. Based on concern for malignancy, left orchiectomy was performed. Pathology revealed infarction of the testicular parenchyma with necrotizing vasculitis in the parenchyma, epididymis, and spermatic cord. Systemic vasculitis was considered, but CBC, ANCA, ANA, and hepatitis C antibodies were negative.
One month following orchiectomy, he developed symptoms in his right testicle. He was started on prednisone. Due to recurrent symptoms in his remaining testicle upon weaning prednisone, azathioprine was added as a steroid-sparing agent. The patient has had no relapse for 5 years. The lack of clinical progression and repeatedly normal labs support the diagnosis of single organ vasculitis (SOV), presenting as isolated testicular vasculitis (ITV).
Discussion: Hospitalists frequently consider the diagnosis of vasculitis when patients present with organ inflammation. Systemic vasculitis involves inflammation of blood vessels involving multiple territories or organs. Less commonly, vascular inflammation may be restricted to a single organ, such as in SOV. Testicular vasculitis can be a manifestation of systemic vasculitis or SOV. Literature supports SOV as an etiology for testicular pain (i.e., ITV) with no systemic symptoms or inflammatory markers. Initially, ITV can mimic other focal disease processes and is often mistaken for neoplasm until orchiectomy and review of pathology, as in our patient. In a patient with testicular vasculitis, one must distinguish between systemic and SOV, which has important treatment implications. Systemic vasculitis, such as polyarteritis nodosa, has multi-organ involvement, necessitating use of cyclophosphamide. In our patient, avoidance of cyclophosphamide prevented sterilization, which was of particular importance given his age and prior left orchiectomy.
Conclusions: This case exemplifies the challenge of diagnosing SOV manifesting as ITV and distinguishing it from systemic vasculitis with presentation in the testicle. If possible, prompt differentiation of SOV from systemic vasculitis and malignancy may prevent aggressive treatment and surgery.