Co-existence of renal hydatid cyst and renal cell carcinoma in one kidney: A case report

Rationale: Cystic echinococcosis (hydatid disease) is a parasitic infection of humans, but renal hydatid cyst is rare. It is even more uncommon to find hydatid cyst and renal cell carcinoma (RCC) synchronously in one kidney. Patient concerns: This report presents a 47 years old Iranian man with the chief complaint of lower abdominal pain. Abdominal ultrasound and computed tomographic scan was performed for more evaluation. Diagnosis: RCC was the most probable diagnosis, so he went under left total nephrectomy. Eventually, after histopathologic examination of the excised kidney, cystic echinococcosis came to the first line and papillary RCC was the second diagnosis. Outcomes and lessons: Diagnosis of hydatid cyst and RCC is mostly based on imaging, but, as we noticed in this case, distinguishing between these two may sometimes be difficult due to radiological similarities.