Abstract
Renal hydatid cyst, an uncommon manifestation of Echinococcus granulosus infection, presents a diagnostic challenge due to its asymptomatic nature. Here, we report the case of a 34-year-old male who presented with intermittent left flank pain, abdominal fullness, and passage of whitish clots in urine. Physical examination revealed a palpable 15 cm × 11 cm hard mass extending from the left hypochondrium to the left lumbar region. Ultrasonography and contrast-enhanced computed tomography identified a 15 cm Bosniak type 3 complex cystic lesion arising from the left kidney, causing hydronephrosis and hydroureter. The patient underwent a left nephrectomy, and a histopathological examination confirmed a renal hydatid cyst. This case highlights the diagnostic difficulty in differentiating renal hydatid cysts from other renal lesions. Despite suggestive radiological findings, conclusive diagnosis remains elusive, particularly in solitary complex renal cysts. Awareness of renal hydatid cysts in the differential diagnosis is crucial for appropriate management.