Incidental Renal Botryomycosis in a Nonfunctioning Kidney

Botryomycosis is a unique form of bacterial infection, closely mimicking actinomycosis. The usual site of occurrence is the skin and renal botryomycosis is very rare. The most common organism is Staphylococcus aureus which can be identified using Gram stain and confirmed by culture. Early and accurate diagnosis can ensure appropriate antibiotic therapy. We present a young lady diagnosed to have incidental botryomycosis of the kidney, following nephrectomy. 1. Introduction Botryomycosis is a rare chronic suppurative bacterial condition characterized by the presence of masses of fungus-like sulphur granules. This infection may involve the skin or visceral organs [1, 2]. To the best of our knowledge, very few cases of renal botryomycosis have been reported in the literature [3–5]. 2. Case Report A 29-year-old nondiabetic lady presented with right loin pain and fever of two months duration. The urine microscopy revealed numerous red blood cells and bacteria, and serum urea and creatinine levels were normal. An intravenous pyelogram showed a staghorn calculus. A dimercaptosuccinic acid (DMSA) scan performed at the same visit showed a right hydronephrotic, poorly functioning kidney (Figure 1). A right percutaneous nephrostomy with double J stenting was performed and pus was obtained during the procedure. She was discharged with a right DJ stent left in situ. Six weeks later, she presented with persistent loin pain and diethylene triamine pentaacetic acid (DTPA) renogram showed a poorly functioning right kidney (19.29%). A right nephrectomy was undertaken and the specimen was sent for histopathological examination. Grossly, the right kidney appeared small and shrunken with cortical scarring and adherent capsule. Cut section of the kidney revealed cortical atrophy with a dilated pelvicalyceal system containing luminal necrotic debris. On histopathological examination, the renal interstitium showed fibrosis and dense inflammation composed of lymphocytes, plasma cells, neutrophils, eosinophils, and occasional multinucleated giant cells. The tubules were focally dilated and contained necrotic debris (Figure 2). Occasional glomeruli showed periglomerular fibrosis. The renal parenchyma showed abscesses containing Gram negative organisms surrounded by amorphous eosinophilic material suggestive of Splendore Hoeppeli phenomenon (Figures 3 and 4). These bacterial colonies were negative for Grocott-Gomori silver and Ziehl-Neelson stains. A final diagnosis of renal botryomycosis superimposed on chronic pyelonephritis was rendered. The patient was treated with cefuroxime