Extra-hepatic intra-abdominal hydatid cyst: which characteristic, compared to the hepatic location?

Hydatid cysts are mostly located in the liver, followed by the lung. Primary and isolated extrahepatic intra-abdominal hydatid cysts (PIEHC) are rare and only a few sporadic series have been reported. This article aims to study the epidemiological, diagnostic difficulties and therapeutic principles of PIEHC. More over, it aims to make comparison between PIEHC and the liver location of the cyst concerning all these data. We report a retrospective study from January 1995 to September 2010 concerning 34 patients who underwent surgical removal of a PIEHC. The mean age was 46 years. Abdominal pain was the main symptom, and was found in 27 patients (79.4 %). Physical examination revealed an abdominal mass in 19 patients (55.9 %). In 6 patients (17.6 %) the PIEHC was incidental. Abdominal ultrasound and abdominal CT scan helped to highlight all cystic masses. The diagnosis was established preoperatively in 28 patients (84.8 %). Five patients (14.7 %) were operated with a diagnosis other than PIEHC. The diagnosis was made intraoperatively in one case (2.9 %). A laparotomy in 24 cases (70 %) was the surgical approach often used. Majority of the patients, 25 cases (73.5 %), received a conservative procedure. Only 3 patients (8.8 %) had recurrences and were reoperated. The diagnosis of PIEHC is often facilitated by means of modern imaging, however, serious diagnostic problem were found with a pancreatic location of the cyst. Complete surgical excision, when possible without major sacrifice, seems to be the best therapeutic option to reduce the risk of recurrence.