INTRODUCTION: We present a patient with an unusual combination of surgical findings, complicated by both a medical condition and the treatment there of. PRESENTATION OF CASE: A 52 year-old man with Wegener's granulomatosis presented with groin pain and sepsis while on immunosuppressive therapy. Large retroperitoneal abscesses were found on CT scanning, together with a collapsed left lower lobe of the lung, a complete infarct of the spleen, and evidence of diverticulosis. At the exploratory laparotomy, the infarcted spleen was removed and the retroperitoneal abscesses were drained via a separate lateral incision. Uncomplicated diverticular disease were also confirmed. DISCUSSION: The left lower lobe collapse, infarcted spleen and diverticular disease were all potential sources of the sepsis, but none of them could be clearly linked to the abscesses. The splenic infarct and a post-operative myocardial infarct were likely related to his vasculitic disease. CONCLUSION: Patients with systemic vasculitis may present with unusual pathologies, and immunosuppressive treatment may also modify clinical presentation. © 2012 Published by Elsevier Ltd on behalf of Surgical Associates Ltd.