Isolated renal hydatid cyst in a 12-year-old girl: clinical, radiological, and surgical perspectives – a case report

Introduction and importance: Hydatid disease, caused by Echinococcus granulosus , is a zoonotic parasitic infection endemic in livestock-raising regions. While the liver and lungs are the most commonly affected organs, renal involvement accounts for only 2–4% of cases, and less than 2% in children. The rarity and nonspecific presentation of renal hydatid cysts make diagnosis challenging, often mimicking other cystic renal pathologies. Aim of the study: The aim of this study is to report a rare case of isolated renal hydatid cyst in a pediatric patient and to highlight its clinical presentation, radiological features, diagnostic challenges, and surgical management. By integrating clinical, serological, and cross-sectional imaging findings, this case aims to emphasize the importance of considering hydatid disease in the differential diagnosis of complex renal cysts in children from endemic regions, and to reinforce the role of renal-sparing surgical techniques in achieving favorable outcomes while preserving renal function. Case presentation: A 12-year-old girl from a rural area presented with a 2-week history of dull, progressive left flank pain without urinary or systemic symptoms. Physical examination revealed a palpable, non-tender left flank mass. Laboratory findings were normal. Ultrasonography and contrast-enhanced CT of the kidneys revealed a well-circumscribed cystic lesion (10.5 × 9 cm) with internal septations, daughter cysts, and focal wall calcifications features suggestive of a hydatid cyst. Serology confirmed E. granulosus infection. The patient underwent successful cyst enucleation via a left flank incision, with intraoperative findings consistent with hydatid disease. Postoperative recovery was uneventful, and no recurrence was noted during follow-up. Clinical discussion: Renal hydatid disease in children is extremely rare and can clinically resemble multilocular cystic nephroma or cystic renal cell carcinoma. Cross-sectional imaging combined with serology enables accurate preoperative diagnosis, guiding surgical management and preventing cyst rupture or spillage. Renal-sparing procedures, such as cyst enucleation, are preferred in pediatric patients to preserve renal function. Conclusion: Isolated renal hydatid cysts, though rare in children, should be considered in endemic regions. Early recognition and renal-sparing surgery ensure favorable outcomes and functional preservation.