Renal, colonic and retroperitoneal actinomycosis--a case report.

An unusual case of actinomycosis involving the kidney, retroperitoneum and colon is reported. A 41 year old patient with two weeks history of loin pain was found to have a palpable renal mass on clinical examination. Imaging revealed a solid mass arising from the left kidney, invading the retroperitoneum suggestive of an invasive hypernephroma. A nephrectomy, partial resection of psoas and colonic resection with end to end anastomosis was performed. Histopathology revealed renal actinomycosis with involvement of the adjacent colon and retroperitoneum. He recovered well after surgery and was treated with penicillin for one year. Five years have elapsed since presentation without any evidence of clinical recurrence. Abdominal actinomycosis though rare, should be borne in mind while investigating patients presenting with an abdominal mass.