Hydatid cyst of the breast.

Hydatid disease (hydatid cyst or echinococcal disease) is contracted in humans through oral transmission by ingestion of eggs. Hydatid disease most frequently affects the liver and the lungs. Involvement of the breast is rare. A combination of radiological and cytological findings usually suggests the correct diagnosis. We present mammography and cytology findings of primary hydatid disease of the breast in a 56-year-old woman.