Renal actinomycosis mimicking renal carcinoma

The case of a 52-year-old man is reported who presented with night sweats a nd slight debilitation, Upon CT scan a left-sided renal mass with centrally liquefied areas was detected. The patient underwent nephrectomy for suspec ted renal cancer with central necrosis. Histologically, the diagnosis of re nal actinomycosis was established based on the detection of sulphur granule s. Actinomyces israelii is an anaerobic gram-positive bacterium that may ca use localized tumour-like infections mainly in the craniocervical region an d exceptionally retroperitoneally, Renal actinomycosis is a rare differenti al diagnosis of renal masses. As nephrectomy may prove hazardous in these c ases, the diagnosis should be attempted pre-operatively by ultrasound-guide d aspiration and consecutive antibiotic treatment, In selected cases surger y could be avoided at all. Copyright (C) 2001 S. Karger AG. Basel.