An Isolated Retrovesical Hydatid Cyst in a Child: A Rare Case Presentation

Hydatid disease is a parasitic infection caused by Echinococcus granulosus. The most common locations of infection are the liver and lungs. This case discusses a rare isolated retrovesical hydatid cyst. The case-report describes a thirteen year old boy who presented with abdominal pain and dysuria. Ultrasound and magnetic resonance imaging demonstrated a multiloculair cyst, pathognomonic for a hydatid cyst. The retrovesical location caused a unilateral renal hydronephrosis. A renogram showed a right sided afunctional kidney due to this compression. Treatment with albendazol was started but the proposed surgery was refused. There are three possible routes of transmission: the first one is fissuring or rupture of a primary hepatic, splenic or mesenteric cyst with seeding of the content in the abdominal cavity. A second possibility is hematogenous or lymphatic dissemination. The third hypothesis, which we assume is the most probable in this case, is migration through the haemorrhoidal vessels of the rectal ampulla to achieve a retrovesical location.