A rare phenotype of breast hydatid cyst causing misdiagnosis and unnecessary intervention: a case report.

Hydatid cyst (cystic echinococcosis) is a chronic parasitic infection by the larval stage of the cestode that is called resulting in the development of cystic lesions in animals and humans. In this report, we describe a rare phenotype of hydatid cyst in the breast of a 23-year-old female presented with breast mass in the left upper outer quadrant for 3 months with palpable left axillary lymph nodes. Both US and mammography provided a picture of complex suspicious cystosolid lesion with amorphous micro-calcification (BIRAD-4A). Surgical consultation was performed and Tru-Cut biopsy was recommended. Histopathology results revealed multiple viable protoscolices of and suggested the final diagnosis of breast hydatid cyst. The patient returned with ruptured and infected hydatid cyst of the breast and started treatment with Albendazole 400 mg twice daily in addition to antibiotics. Following-up after two months of Albendazole treatment showed a dramatic shrinkage in the size of the cystic lesion. In conclusion, hydatid cyst should be considered as a differential diagnosis of any cystic or cystosolid lesion in the breast and any organ in the body from head to toe apart from the hair and nails. Radiologists should be aware to the benign lesions that may mimic breast cancer to avoid misdiagnosis and unnecessary invasive procedures and consequent complications.