Bilateral supernumerary pectoral muscle

Abstract

Pectoral muscles are important muscles in the anterior chest wall, and they have a key role in the axillary region from the point of view of imaging and surgical procedures. In the present case, there was a presence of supernumerary pectoral muscles on both sides. Both of them were lying deep to pectoralis major muscle, arising inferior to but in the same plane of the pectoralis minor muscle. There were three slips of muscle present on the left side and only one slip on the right side. Laterally, these slips were merging with the deep part of the lower border of pectoralis major muscle. They seem to be the part of the pectoralis major of their respective side, which probably failed to migrate along with it during embryological development. Such supernumerary pectoral muscles cannot be ignored as their presence can considerably influence different clinical scenarios.

Keywords

• Accessory
• axillary lymph nodes
• imaging
• pectoralis muscle
• supernumerary