Renal hydatid cysts and the evaluation of their radiologic images

We present our experience with the various sonographic and CT findings observed in patients with hydatid disease involving the kidney. The imaging characteristics of various echinococcal cysts were evaluated comparatively to offer a diagnostically better explanation for the radiologic images and to assist the urologist in defining the nature of the cyst and its content preoperatively. Renal involvement is extremely rare in patients with hydatid disease.

The clinical and radiological features in 17 patients with renal hydatid disease are described. Two patients (4 and 28 years old) had renal colic with passage of debris in urine (hydatiduria). Five males and twelve females were 4-61 years old (mean 37 years). Their histories, physical findings and imaging procedures were evaluated. Plain abdominal radiographs were taken in 17 patients.

Plain film showed calcified mass compressing the pelvicalyceal system and/or ureter in 10 cases. Sonography showed typical features of echinococcal cysts in 14 cases, especially in the liver and spleen.

Sonography demonstrates the internal cystic content better. When daughter cysts are present, CT establishes the diagnosis. CT scan provides further information on the affected organ and involvement of other organs, calcification of the cyst wall and density. The diagnosis was suggested preoperatively in all patients, and confirmed surgically in 12 patients. Eight total nephrectomies and four partial nephrectomies were performed. The others are being followed up.