oozzssll7/!3Wl596-2076$03.~ TEE J ~ A L OF UROLOGY Copyright 8 1998 by AMERICAN UROUXIC;~. AS~OCIATION, INC.

Vol. 159,2076, June 1998 F’rinted in U.S.A

RENAL BOTRYOMYCOSIS MIMICKING RENAL CELL CARCINOMA KUTSAL YORCJKOC;LU, ERDENER OZER, MURAT SADE, KADIR BIBERO&AJ AND ZIYA KIRKALI

From the Departments of Pathology, Urology and Internal Medicine, Dokuz Eyliil University, School of Medicine, Izmir, Turkey KEY WORDS: kidney, nephrectomy

Botxyomycosis is characterized by a chronic suppurative le- sion with distinctive fungus-like grains similar to sulfur gran- ules in actinomycosis.1 The integumentary and visceral forms are recognized.’ Only 2 of the previously reported 6 renal bot- ryomycosis cases were isolated, which simulated renal cell car- cinoma radiologically and clinically, and actinomycosis and my- cosis pathologically.2.3 We report on a patient in whom isolated renal botryomycosis was preoperatively diagnosed as renal cell carcinoma and who underwent radical nephrectomy.

CASE REPORT

A 57-year-old man presented with right renal colic and fever 4 months in duration. He had a 10-year history of type I1 diabetes mellitus and had undergone extracorporeal shock wave lithotripsy elsewhere for right ureteral stones on 2 occasions. Physical examination demonstrated tenderness and pain on palpation of the right lumbar region. Abdominal ultrasonography and computerized tomography of the abdo- men revealed a solid 5 cm. mass at the lower pole of the right kidney (fig. 1). Escherichia coli was cultured from the urine.

The preoperative diagnosis was renal cell carcinoma and right radical nephrectomy was performed. The mass invaded the perirenal adipose tissue, psoas muscle and liver at sur- gical exploration, and it was completely resected. Pathologi- cal evaluation demonstrated that the mass consisted of con- fluent abscesses extending into perirenal adipose tissue. Centrally these abscesses contained Gram-negative bacilli surrounded by amorphous eosinophilic material, termed the Splendore-Hoeppli phenomenon (fig. 2). Histochemical stains (Gomori methenamine silver for actinomyces and fungi, and Brown-Hopps tissue gram stain) confirmed the diagnosis of botryomycosis. Postoperatively the patient was treated with 2 gm. cephalosporin daily and convalescence was uneventful.

Accepted for publication November 21, 1997.

1.

2.

3. FIG. 1. Computerized tomography shows solid renal mass at lower

pole of right kidney.

FIG. 2. Microscopic section of abscess with Splendore-Hoeppli henomenon (arrow) and glomerulus (arrowhead). H & E, reduced

E-om x20.

DISCUSSION

Botryomycosis is an unusual chronic localized infection of the skin and subcutaneous tissues caused by nonfilamentous bacteria. Visceral involvement is uncommon. We report the seventh case of renal botryomycosis.2v3 On histological study botryomycosis is difficult to differentiate from actinomycosis and mycosis. Therefore, histochemical stains are necessary to make the differential diagnosis.

The suggested factors in the pathogenesis are host resistance, organism virulence, delayed hypersensitivity reactions and phagocytosis defects. The disease is known to develop in immu- nocompetent patients,’ and our patient was seronegative for human immunodeficiency virus. Our case appears to be an example of botryomycosis in an immunologically competent patient with impaired phagocytosis due to diabetes mellitus.

Although advanced imaging techniques today provide an accurate diagnosis of solid renal masses, uncommon causes may sometimes mimic renal cell carcinoma. Khalaff et a1 reported on a patient in whom renal actinomycosis was di- agnosed by numerous biopsies obtained intraoperatively and in whom the kidney was then p r e s e ~ e d . ~ All other reported cases of actinomycosis and botryomycosis were diagnosed using radical surgery specimens. It is difficult to diagnose botryomycosis preoperatively. However, it should be consid- ered in the differential diagnosis of renal masses. In conclu- sion, awareness of these unusual lesions and frozen section of intraoperative biopsies in immunocompetent patients with suspected renal cell carcinoma may make preservation of the kidney possible.

REFERENCES

Schlossberg, D., Keeney, G. E., Lifton, L. J. and Azizkhan, R. G.: Anaerobic botryomycosis. J. Clin. Microbiol., 11: 184, 1980.

Richmond, I. and Mene, A.: Renal botryomycosis. Histopathol- ogy, 2 0 67, 1992.

Khalaff, H., Sngley, J. R. and Klotz, L.: Recognition of renal actinomycosis: nephrectomy can be avoided. Report of a case. Canad. J. Surg., 3 8 77, 1995.

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