Primary renal hydatid cyst: mis-interpretation as a renal malignancy.

Primary renal echinococcosis, a rare disease involving the kidney, accounts for 2-3% of human echinococcosis. A 64-year-old female patient from Uzbekistan presented with complaints of left flank pain. A CT scan revealed a cystic mass in the upper to midpole of the left kidney. We regarded this lesion as a renal malignancy and hand-assisted laparoscopic radical nephrectomy was performed to remove the renal mass. The mass consisted of a large unilocular cyst and multiple smaller cysts without any grossly visible renal tissue. The final pathologic diagnosis was a renal hydatid cyst. For patients from endemic areas, hydatid cyst should be included in the differential diagnosis. Here, we present a case of renal hydatid cyst in a female patient who relocated from Uzbekistan to Korea.