[Hydatid cyst of the trapezius muscle: an unusual location].

Echinococciasis, or hydatid disease, is a broad-based anthropozoonosis common to humans and several mammal species. The disease results from the development of the larval or hydatid form of the canine tenia (Echinococcus granulosis) in the body. Hydatid cysts are uncommonly found in muscles, even in endemic zones. The purpose of this study was to present an unusual case of hydatid located in the trapezius muscle in a 10-year-old girl and to describe the epidemiological, clinical, and therapeutic aspects of hydatid cysts observed in muscles through this case study and a review of the literature.