Pelvic retroperitoneal hydatid cyst secondary to rupture of a liver hydatid cyst
The magnetic resonance image (Fig. 1) demonstrates an 18 × 15-cm hydatid cyst in the pelvic retroperitoneum (thick arrows) and a smaller 6 × 5-cm hydatid cyst in the right lobe of the liver (thin arrow). The characteristic features of daughter cysts are present. The patient underwent excision of the retroperitoneal and liver cysts and received albendazole therapy for 6 weeks.
Hydatid cysts are ubiquitous, having been described in virtually every location in the body. Cysts located in the pelvis can be both retrovesical, intraperitoneal or retroperitoneal. They present with symptoms related to the mass effect and with obstructive urinary symptoms.1–3 The primary occurrence of these cysts is probably explained by hematogenous spread. The concurrent occurrence with hepatic cysts may be explained by secondary implantation following rupture of the primary hepatic cyst. Retrovesical location can occur from intraperitoneal rupture of a hepatic cyst. The retroperitoneal location is likely to be due to rupture of the hydatid cyst into the bare area of the liver and subsequent retroperitoneal descent to the pelvic location.4 When a retroperitoneal cystic lesion is found, a hydatid etiology must be suspected in regions where hydatidosis is endemic and the concurrent hepatic cysts must be sought. Treatment is by surgical excision of the cysts followed by albendazole therapy.