Hydatid disease of the tarsal bones. A case report.

Hydatid disease is caused by the larval form of the tapeworm Echinococcus. Osseous cysts are rare and very few cases of foot infestation have been reported. We present the case of a 51-year-old woman who developed a palpable mass at the medial dorsal aspect of the right midfoot. Radiological examination showed cystic lesions in the cuneiforms and the navicular. The lesion was explored and several small cysts containing clear fluid were found. They were evacuated and the bone was curetted. The diagnosis of E. granulosus infestation was made histologically. After 15 years' follow-up there were no signs of recurrence. Osseous echinococcosis is a rare disease that may present as infective or neoplastic pathology. A high index of suspicion is necessary for its diagnosis, especially in patients who live in or travel to sheep-raising areas where hydatid disease is endemic.