Purpose: Isolated extrarenal retroperitoneal echinococcal cyst is a rare manifestation of hydatid disease. We review the clinical findings of a series of isolated retrovesical and retroperitoneal hydatid cysts in an endemic area, with special emphasis on diagnostic pitfalls.
Materials and methods: A retrospective 15-year review in a rural area of central Spain (600,000 population), with a global incidence of hydatidosis of 10 new cases per 100,000 population per year, revealed 10 patients (0.1 cases per 100,000 per year) with surgically treated primary extrarenal retroperitoneal echinococcosis and absence of other hydatid cysts in any organ. Clinical, radiological and laboratory data are analyzed. The literature of the last 15 years on hydatid disease with a primary 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 and age ranged from 8 to 79 years (mean 42.2 +/- 5.4). The most frequent presentation was a palpable mass in 29% of the cases followed by flank pain in 24%, frequency in 17% and urinary retention in 14% of the cases. Hydatiduria of the urinary tract was present in 9.5% of the cases. Different serological investigations were performed in 45% of the cases with positive results in 68%. The lesion had been surgically removed in all cases. Therapy and followup of each patient were analyzed.
Conclusions: An isolated retrovesical, retroperitoneal or even retrocrural 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 are proposed.