Asian Journal of Medical Research and Case Reports

The rectus sternalis is a relatively common anatomical deformity encountered in anatomical practice, occasionally present in humans, and well known to anatomists. This muscle may be incidentally discovered during oral and maxillofacial surgery because myocutaneous flaps (pectoralis major musculocutaneous flap, delto-pectoral flap) in the thoracic region are often utilized for reconstruction after resection of malignant tumors. In this report, we present a case involving an 82-year-old man with large bilateral rectus sternalis. The purpose of presenting this case is to remind us of the importance of anatomical knowledge in all medical procedures. This muscle is longitudinally aligned along the lateral aspect of the sternum and in front of the pectoralis major muscle. Based on its innervation, there is a consensus that the rectus sternalis may be part of the pectoralis major muscle or part of the rectus abdominis muscle. The rectus sternalis is more common in female than in male patients, and it occurs twice as often unilaterally as bilaterally. Furthermore, its incidence is dependent on sex, race, and ethnicity and is particularly high among Asians. It is important for the health care professional to identify this muscle in the early stages of clinical decision-making.