Músculo esternalis: variante anatómica que simula neoplasia en mamografía

The sternalis muscle is a rare anatomical variant of the chest wall. Its frequency is estimated at approximately 8% of the world population, both in men and women, and can be unilateral or bilateral. Its importance is due to the fact that it can simulate malignancy on mammography. Recognizing it avoids performing unnecessary additional imaging studies, including guided biopsies involving extra financial costs to the system, as well as undue stress and anxiety in patients.