An X across the Chest: A Rare Case of a Criss-crossed Sternalis Muscle

The present case study aims at drawing attention to a very rare presentation of the sternalis muscle noticed during routine dissection, and is intended to highlight the clinical significance and usefulness of this unique muscle in reconstructive surgeries, especially of the breast.

Though many morphological variants of the muscle have been reported, we came across a unique bilateral sternalis muscle during routine dissection for undergraduate medical teaching, in an 80-year-old male cadaver. The muscle originates on both sides from the external oblique aponeurosis from the fleshy belly, and after becom-ing tendinous, converges in the midline to form a common tendon at the level of the sternal angle, and then splits again into two tendons which become continuous with the ipsilateral sternocleidomastoid.

Notwithstanding the fact that the presence of a sternalis can be misdiagnosed as a wide range of anterior chest wall lesions and tumors, especially with misdiag-nosis of breast masses in routine mammograms, it has great use as a muscular flap for reconstructive surgeries of the anterior chest wall, head, neck and breast.