Renal ultrasonography and detection of pseudomycelium in urine as means of diagnosis of renal fungus balls in neonates

Abstract

Objective. To present a series of neonates with renal fungus balls diagnosed by ultrasonography, urine culture and/or by the detection of Candida pseudomycelium in urine. Patients and methods. We revised the clinical records of neonates for whom the diagnosis of renal fungus ball was established by ultrasound and laboratory studies; these patients had been hospitalized at the National Institute of Pediatrics in Mexico between January 1st, 1999 and December 31st, 2002. Results. During the study period, 9 neonates were diagnosed with renal fungus ball. In 7 cases, the ethiologic agent was Candida albicans; whereas it was C. tropicalis in one case and C. parapsilosisin the other. Urine culture was positive (≥10,000 UFC/ml) in 8 cases, whereas the fungal density was only 2400 UFC/ml in the last sample. Pseudohyphae were present in all cases and ultrasonography showed fungus ball in every case. All patients received a single antifungal drug, either amphotericin B or fluconazole. All the patients recovered and none of them required surgical treatment. Control postreatment by ultrasound studies showed that the fungus balls had disappeared in every case. Conclusion. The diagnosis of Candida renal fungus balls based on the ultrasound study and urine culture is also substantiated by the detection of pseudomycelium in the centrifugation pellet of urine samples, which is a fast diagnostic method. This approach permitted an early diagnosis and treatment of Candida renal fungus balls.