ISOLATED RETROVESICAL AND EXTRARENAL RETROPERITONEAL HYDATIDOSIS - CLINICAL-STUDY OF 10 CASES AND LITERATURE-REVIEW

Purpose: Isolated extrarenal retroperitoneal echinococcal cyst is a ra re manifestation of hydatid disease. We review the clinical findings o f a series of isolated retrovesical and retroperitoneal hydatid cysts in an endemic area, with special emphasis on diagnostic pitfalls. Mate rials and Methods: A retrospective 15-year review in a rural area of c entral Spain (600,000 population), with a global incidence of hydatido sis of 10 new cases per 100,000 population per year, revealed 10 patie nts (0.1 cases per 100,000 per year) with surgically treated primary e xtrarenal retroperitoneal echinococcosis and absence of other hydatid cysts in any organ. Clinical, radiological and laboratory data are ana lyzed. The literature of the last 15 years on hydatid disease with a p rimary retroperitoneal and retrovesical location is reviewed. Results: A total of 42 cases of isolated retrovesical (25) and retroperitoneal (17) hydatidosis was compiled. Male predominance of 2.5:1 was noted a nd age ranged from 8 to 79 years (mean 42.2 +/- 5.4). The most frequen t presentation was a palpable mass in 29% of the cases followed by fla nk pain in 24%, frequency in 17% and urinary retention in 14% of the c ases. Hydatiduria of the urinary tract was present in 9.5% of the case s. Different serological investigations were performed in 45% of the c ases with positive results in 68%. The lesion had been surgically remo ved in all cases. Therapy and followup of each patient were analyzed. Conclusions: An isolated retrovesical, retroperitoneal or even retrocr ural cyst can be the unique manifestation of hydatid disease. Although difficult, preoperative diagnosis is desirable for the selection of a surgical approach and prevention of allergic reactions and operative spillage. A diagnostic algorithm and several therapeutic guidelines ar e proposed.