Hydatic cyst is a crucial and prevalent parasitic disease in the developing countries in the Mediterranean region. Its diagnosis is sometimes problematic because of non-specific complaints and unavailability of any positive results in a routine laboratory analysis. Isolated renal hydatid cysts are very rare. In this study, a primary left renal hydatid cyst which was found in a 12-year-old boy was presented. He was referred by another hospital to our department with a flank pain and cystic mass in left kidney. Indirect haemagglutination test (IHA) for Echinococcus was negative. Nephrectomy was performed with the diagnosis of renal cyst hydatic. Renal cyst hydatid may present with various clinical findings ranging from asymptomatic clinical course to total loss in renal function. It will be beneficial to consider a renal hydatid cyst in patients with blurred flank pain, even if IHA is negative.
Keywords: Hydatic cyst; renal hydatic cyst; nefrectomia.