[Isolated hydatid cyst of the kidney].

BACKGROUND A hydatid cyst is a parasitic disease caused by the tapeworm Echinococcus granulosus. Kidney involvement represents 4% of all cases, and is rare compared to that in the liver or lung, even more as an isolated site of infection. We present a case report of a woman with septic status, cutaneous fistula and a renal cystic mass revealed to be a solitary hydatid cyst of the kidney. METHODS A 60-year-old woman was referred acutely by another hospital to our department because of septic fever, cutaneous lumbar fistula and a left kidney cystic mass of 10 x 8 cm. We suspected a renal abscess and the patient underwent immediate left nephrectomy. RESULTS We performed an extraperitoneal nephrectomy with a lumbar access under the 12th rib with complete resection of the fistula. The histopathological examination revealed it to be a hydatid cyst involving 2/3 of the kidney. After surgery a medical therapy with albendazol was administrated for 6 months, and the patient did not have any other localization 24 months after surgery. CONCLUSIONS An isolated renal hydatid cyst presenting as cutaneous fistula with a septic status is a very rare condition. A pre-surgical diagnosis is not always possible as in this case. The surgical therapy (nephron-sparing or radical) is the key of the success and a medical therapy after surgery is recommended to prevent other localizations of this parasitic disease.