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Answer: D. Renal lymphoma. Although cystic presentation has been reported, it is highly unusual.

After additional laboratory evaluation, left nephrectomy was performed.

Specimen photograph shows a large cyst arising from the left kidney containing multiple smooth-walled daughter cysts.

Diagnosis: Renal Hydatid Disease

  • Hydatid disease is a worldwide zoonosis caused by the larval stage of the Echinococcus tapeworm, primarily E granulosus.

  • Endemic to many sheep- and cattle-raising regions of the world (Mediterranean, Africa, South America, the Middle East).

  • Life cycle involves two hosts: the definitive host, usually a dog or other carnivore, and the intermediate host, most commonly sheep.

  • Humans may become intermediate hosts by ingestion of contaminated food or water.

  • The liver (75%) and lung (15%) are the most commonly affected organs.

  • Renal hydatid disease is rare (2-3% of cases).

  • Imaging appearances vary and may include 1) a unilocular cyst without internal architecture in the initial stages, 2) a cyst with multiple daughter cysts, or 3) a completely calcified cyst representing the death of the parasite.

  • Immunodiagnostic tests can be helpful in the diagnosis.

  • Treatment is primarily surgical, consisting of total or partial nephrectomy.


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  • Polat P, Kantarci M, Alper F, Suma S, Koruyucu MB, Okur A. Hydatid disease from head to toe. RadioGraphics 2003; 23:475-494.
  • Ilica AT, Kocaoglu M, Zeybek N, Guven S, Adaletli I, Basgul A, Coban H, Bilici A, Bukte Y. Extrahepatic abdominal hydatid disease caused by Echinococcus granulosis: Imaging findings. AJR 2007; 189:337-343.
  • Göğüş Ç, Şafak M, Baltaci S, Türkölmez K. Isolated renal hydatidosis: Experience with 20 cases. J Urol 2003; 169:186-189.
  • Angulo JC, Sanchez-Chapado M, Diego A, Escribano J, Tamayo JC, Martin L. Renal echinococcosis: Clinical study of 34 cases. J Urol 1997; 157:787-794.
  • Poulios C. Echinococcal disease of the urinary tract: Review of the management of 7 cases. J Urol 1991; 145:924-927.

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