Sternalis and transversus thoracis muscles: An anatomical variation and its clinical implicationss

An unusual muscle was discovered during the dissection of the presternal and pectoral regions, which, according to Jelev classification, can be considered a sternalis muscle. The identified right sternalis muscle has a common origin with the sternal head of the right sternocleidomastoid muscle and then splits in two bellies, the right one, much longer, which inserts on the right 2nd–5th costal cartilages, and the left one which inserts on the 2nd–3th left sternocostal joints. The sternalis muscle was associated with a very poor developed right transversus thoracis muscle. The study is important for the anatomists and more important for the clinicians, as this muscle's presence may cause diagnostic errors in the pectoral region.