Large Solitary Renal Echinococcal Cyst in an Elderly Female: A Rare Case Report

Abstract

Aim: The aim of this case report is to emphasize the importance of parasitic etiologies as one of the differential diagnoses of renal cystic lesions that can be misdiagnosed as neoplasms. Case Presentation: We report a case of a 68-year-old female who presented with complaints of abdominal distension and right flank pain for six weeks. She had no significant past medical history. On examination, the abdomen was soft, non-tender, with no hepato-splenomegaly. Laboratory investigations were unremarkable except for mild anemia. Abdominal Ultrasonography revealed a large cystic lesion,72x84x103 mm approximately, arising from the upper pole of right kidney and extending up to the right hepatic lobe. CT scan confirmed a well -defined, non-enhancing cyst with peripheral calcifications (Bosniak II). This led to the suspicion of a hydatid cyst and the patient was investigated for Echinococcus granulosus IgG serology which came out to be positive. Consequently, the patient underwent laparoscopic cystectomy and histopathology confirmed a hydatid cyst by demonstrating lamellated membranes with inflammatory infiltrate. The patient was advised to take Albendazole 400mg twice daily for 3 months. Clinico-radiological assessment showed no recurrence of the disease.  Discussion: A Solitary hydatid cyst of the kidney is a rare finding, representing less than 3% of cases. These are often misinterpreted as renal or hepatic malignancies, making the therapeutic intervention challenging. Clinical and radiological surveillance, together with serological assessment for Echinococcus granulosus are essential for diagnosis. Surgery remains the main treatment, while medical therapy with Albendazole may also be considered. Several case reports based on Laparoscopic approaches have shown favorable outcomes. Conclusion: Large Renal hydatid cysts are a rare clinical entity which can be mistaken for malignancy. Considering the possibility of echinococcosis as a differential for renal cystic lesions, especially in endemic regions, is essential. Early recognition through imaging and serology, followed by timely surgical intervention, is important for achieving favorable outcomes.