Renal echinococcosis: clinical study of 34 cases

Hydatid disease, a cyclo-zoonotic parasitic infestation caused by the larval stage of the cestode Echinococcus granulosus, is prevalent worldwide. We reviewed the clinical findings of a large series of renal hydatidosis treated in an endemic area with special emphasis on diagnostic pitfalls.

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 34 with renal echinococcosis treated surgically (3 to 4% of officially confirmed cases of hydatidosis). Clinical, radiological and laboratory data were analyzed.

Renal hydatid disease mimicked other diseases. The combination of clinical history, imaging studies, and serological and urine investigation yielded a reliable pretreatment diagnosis in only 50% of cases and a presumptive diagnosis in 71%. Among imaging studies computerized tomography was the most valuable diagnostic examination. Moderate eosinophilia was found in half of the cases, while a third had scoleces in the urine. A diagnostic and therapeutic algorithm is presented.

Preoperative diagnosis of renal hydatid disease is difficult even in an endemic zone. Imaging studies are suggestive but usually inconclusive, and the differential diagnosis with a renal tumor or complicated cyst may not be made without surgery. Renal sparing surgery is possible in a significant proportion of cases, particularly when preoperative diagnosis has been considered. Significant surgical morbidity can be expected, and the risk of anaphylaxis and hydatid seeding, although low, should not be overlooked.