International Journal of Urology (2006) 13, 174–176 Blackwell Publishing AsiaMelbourne, AustraliaIJUInternational Journal of Urology0919-81722006 Blackwell Publishing Asia Pty LtdFebruary 2006132174176Case Report Renal echinococcosis P Sountoulides et al. Correspondence: Petros Sountoulides, MD, Agiou Evgeniou 15–17, 55133, Thessaloniki, Greece. Email: petro-s@otenet.gr Received 9 January 2005; accepted 6 April 2005. Case Report Nephrectomy for benign disease? A case of isolated renal echinococcosis PETROS SOUNTOULIDES, 1 IOANNIS ZACHOS, 1 STAVROS EFREMIDIS, 2 ATHANASIOS PANTAZAKOS 1 AND THOMAS PODIMATAS 1 1 Department of Urology, Agios Andreas General Hospital of Patras, Patras, and 2 Department of Clinical Radiology, University Hospital of Ioannina, Ioannina, Greece Abstract Cystic hydatid disease may be found in virtually any organ, although involvement of the urinary tract is relatively uncommon. We report a case of isolated renal hydatid disease presenting with hydatiduria. A short review of the literature regarding diagnosis and management of renal echinococcosis is also presented. Key words hydatiduria, nephrectomy, renal echinococcosis. Introduction Isolated renal hydatidosis is an uncommon presentation of echinococcal disease and occurs in only about 2% of all cases. 1 We present a case of isolated renal hydatidosis treated by total nephrectomy due to communication of the hydatid cyst with the collecting system. Case report A 74-year-old man presented to our hospital complaining of right flank pain for the past 2 months, accompanied by passing grape-like material in his urine. Physical examina- tion revealed right flank tenderness, and moderately ele- vated blood pressure. The patient’s medical history was insignificant; however, he admitted being in close contact with dogs and sheep, as he was working in a farm. Urinal- ysis showed microscopic hematuria, other routine blood tests were normal. Plain abdominal film showed calcifications in the right renal area. Ultrasonography revealed a complex cystic mass, 50 mm × 90 mm in size, while urography demon- strated severe caliceal distortion and a nonenhancing cystic lesion in the right kidney. We performed retrograde pyel- ography in order to reveal possible communication of the cystic mass with the urinary tract. No clear communication was evident (Fig. 1). The patient was then submitted to a computed tomography (CT) scan, which revealed the pres- ence of a multilocular cystic structure in the right kidney with a well-defined wall, brightly enhancing after contrast medium injection (Fig. 2). The CT scan was negative for cystic lesions in liver and spleen. The histological examination of the voided grape-like material demonstrated free larvae and daughter cysts (hydatid sand); in addition, the indirect hemagglutination test (IHA) turned positive, the diagnosis of isolated renal echinococcosis was highly suspected. The patient was scheduled for total nephrectomy because of the size and obvious rupture of the cyst into the collecting system. Nephrectomy was carried out success- fully, the kidney was removed intact without rupture or violation of the hydatid cyst which could give rise to sec- ondary intra-abdominal metastatic sites of the disease. Albendazole per os was administered prophylactically, both preoperatively and postoperatively. The pathologist reported a multilocular hydatid cyst in the nephrectomy specimen, communicating with the pos- terior wall of the renal pelvis via a narrow, 2 mm wide pore. The patient was in good health at 1-year follow up. Discussion Cystic hydatid disease is a cyclozoonotic parasitic infesta- tion caused by the larval stage of the cestode Echinococcus granulosus. The life cycle of Echinococcus granulosus requires two hosts and depends on the food chain. 2 Dog is the definite host while sheep and other domestic animals are intermediate hosts. Eggs in the feces of the dog con- taminate grass and are ingested by sheep or humans. After ingestion, the eggs hatch in the intestinal mucosa, liberated embryos (larvae) penetrate venules and are carried by the bloodstream to the liver. Approximately 3% of the larvae that escape entrapment in the liver and lungs enter the systemic circulation and infect the kidneys. Usually renal involvement, that constitutes about 2–4% of all cases, is due to a secondary manifestation of the disease. Isolated renal echinococcosis is extremely rare. 3 Wherever they finally locate, larvae undergo vesicula- tion, forming hydatid cysts, which usually grow the most