Breast cystic echinococcosis with ultrasonographic “cerebral gyrus sign”: a case report

Background Cystic echinococcosis (CE), caused by Echinococcus granulosus , is a zoonotic parasitic disease that primarily affects the liver and lungs, with breast involvement being extremely rare. We report a case of breast CE in a 50-year-old Tibetan woman from an endemic area. Case presentation A 50-year-old Tibetan woman from a pastoral area presented with a palpable mass in the left breast.Ultrasonography revealed a mixed-echoic nodule exhibiting a “cerebral gyrus sign” in the glandular layer of the left breast. MRI revealed an oval mass in the upper quadrant of the left breast, showing homogeneous high signal intensity on fat-suppressed T2-weighted images and thin peripheral ring enhancement. The final pathology diagnosis after surgery was breast CE. Conclusions This case highlights the ultrasonographic “cerebral gyrus sign” as a potential imaging clue for breast CE and emphasizes that hydatid disease should be considered in patients from endemic regions presenting with complex breast masses, even with negative serology. Increased awareness of this rare entity may help reduce misdiagnosis and guide appropriate clinical management.