Sternalis Muscle: An Unexpected Finding during Mastectomy

Figure 1

(a) Intraoperative photograph showing a thin fleshy ribbonlike muscle of size approximately 10 cm × 3 cm present in the right parasternal region perpendicular to fibres of the pectoralis major muscle. PM: pectoralis major, SM: sternalis muscle. (b) MRI of anterior chest wall (post-MRM) showing a unilateral sternalis muscle (white arrow) in transverse section.

(a)

(b)