[Autochthonous hydatid cyst of the lung].

Cystic echinococcosis, or hydatidosis, also known as hydatid cyst, is a cosmopolitan parasitosis mainly present in breeding areas. This anthropozoonosis is related to the tissue development of an hydatid of an echinococcus tænia, Echinococcus granulosus, found in the digestive tract of canids, at the adult state. In France, this larval cestosis is essentially an import disease developed by patients from endemic areas such as East and North Africa, South America or Asia. However, autochtonous forms, although rare, still persist. Here we describe the case of a 39-year-old non-smoking patient from Paris, admitted in the emergency department for chest pain associated with sweating and chills. The clinical examination found the notion of a right lower lobar pulmonary nodule discovered 20 years ago, on a chest X-ray, but never explored. Thoracic computed tomography shows two large cystic opacities with endocystic flaky images, including one ruptured in the pleura with right pleural effusion. This radiological suspicion of fissured cystic echinococcosis was confirmed by positive hydatidosis serology. The multidisciplinary meeting retained the indication of right basal segmentectomy enlarged to a diaphragmatic patch, associated with treatment by albendazole. The diagnosis was confirmed by parasitological and pathological data. In this article, we will deal with the macroscopic and microscopic features of this rare parasitosis in metropolitan France and we will discuss the elements of management of a fresh resected specimen during macroscopic examination to prevent parasite swarming.