Sonographic diagnosis of primary hydatid disease in the breast: the scroll sign.

Primary hydatid disease of breast is a rare entity and is caused by the larval stage of Echinococcus granulosus. The disease is more commonly seen in sheep-rearing populations and imaging plays a pivotal role in its diagnosis. Several imaging signs have been described in relation to hydatid cysts. However, the "scroll sign," due to the infolding of the endocyst, has rarely been encountered, with only one similar case in literature, in which the imaging findings were inconclusive. We present a case of primary hydatid disease of breast in a young Asian woman, with the sonographic scroll sign.