Isolated Retroperitoneal Hydatid Cyst Invading Splenic Hilum

Introduction. Hydatid disease (HD) is an infestation that is caused by the larval stage of Echinococcus granulosus. The liver is affected in approximately two-thirds of patients, the lungs in 25%, and other organs in a small proportion. Primary retroperitoneal hydatid cyst is extremely rare. The most common complaint is abdominal pain; however, the clinical features of HD may be generally dependent on the location of the cyst. Case Presentation. A 43-year-old female was admitted with the complaint of abdominal pain. Her physical examination was normal. Computed tomography (CT) revealed a ？cm cystic lesion, with a thick and smooth wall that is located among the left liver lobe, diaphragm, spleen, tail of the pancreas, and transverse colon and invading the splenic hilum. Total cystectomy and splenectomy were performed. Pathological examination was reported as cyst hydatid. Discussion. Cysts in the peritoneal cavity are mainly the result of the spontaneous or traumatic rupture of concomitant hepatic cysts or surgical inoculation of a hepatic cyst. Serological tests contribute to diagnosis. In symptomatic and large hydatid peritoneal cysts, surgical resection is the only curative treatment. Total cystectomy is the gold standard. Albendazole or praziquantel is indicated for inoperable and disseminated cases. Percutaneous aspiration, injection, and reaspiration (PAIR) technique is another nonsurgical option. 1. Introduction Hydatid disease (HD) is an infestation that caused by the larval stage of Echinococcus granulosus [1]. It is prevalent in the Middle East, the Mediterranean region, particularly in sheep-raising countries, Australia, Argentina, and Africa. The main hosts are dogs that pass eggs into their feces. Intermediate hosts, for example, sheep, goats, cattle, and human, ingest the eggs and develop cyst formation [2]. Human is the accidental intermediate host in the life cycle of Echinococcus granulosus [3]. The annual incidence of HD has been reported as 18 to 20 cases per 100.000 inhabitants [4]. The larval form of Echinococcus granulosus enters to the lymphatic circulation via penetrating the intestinal mucosa and it is transported to the liver, lungs, and other organs [1]. The liver is affected in approximately two-thirds of patients, the lungs in approximately 25%, and other organs including brain, muscles, ovaries, spleen, kidneys, bones, heart, and the pancreas in a small proportion [5]. Primary retroperitoneal hydatid cyst is extremely rare and only occasional cases have appeared since Lockhart and Sapinza first described this entity in 1958