[Fortuitous discovery of hydatid cyst of the breast].

INTRODUCTION: Hydatid cyst of the breast is rare even in areas of endemic echinococcosis. It accounts for 0.3% of all localizations and 2% of the uncommon sites. It can be isolated or associated with other localizations. CASE: We report the case of a hydatid breast cyst, associated with a pulmonary hydatid cyst, fortunately diagnosed by mammography and ultrasonography. Both cysts were removed. DISCUSSION: Hydatid breast cysts must be considered in any cystic breast mass, particularly in endemic countries.