Bahgat Mohammed, Khan Abdul Sattar, Alsemeh Amira E
Anatomy Division, Biomedical Sciences Department, College of Medicine, King Faisal University, Al-Ahsa, SAU.
Family and Community Medicine Department, College of Medicine, King Faisal University, Al-Ahsa, SAU.
Cureus. 2024 Aug 31;16(8):e68263. doi: 10.7759/cureus.68263. eCollection 2024 Aug.
The sternalis muscle is a rare anatomical variant located in the anterior thoracic wall. Understanding variations in the sternalis muscle anatomy is essential for clinicians, especially radiologists and surgeons to prevent misdiagnosis and avoid complications during surgical procedures in the anterior thoracic region. We present a unique case of bilateral branched sternalis muscles. On either side, the sternalis muscle lies deep to the breast and superficial fascia and superficial to pectoralis major muscle and pectoral fascia. Each sternalis muscle is branched into medial and lateral slips with the medial slip larger than the lateral slip. The medial slip of the right sternalis was larger than the medial slip of the left sternalis. The lateral slip of the left sternalis was larger than the lateral slip of the right sternalis. The lateral slip of the left sternalis muscle has a curved course with superior-lateral convexity and inferomedial concavity. Near its middle, the left sternalis lateral slip is branched into two smaller slips separated by a narrow cleft. The left sternalis muscle in our report is a new variant with multiple branching, which cannot be matched to any type of the previously described classifications. In this case report, we discussed the need of modification of the currently available sternalis classification system to accommodate all types of the previously reported sternalis muscles including the branching pattern of this muscle.
胸骨肌是位于胸前壁的一种罕见解剖变异。了解胸骨肌解剖结构的变异对于临床医生，尤其是放射科医生和外科医生至关重要，可防止误诊并避免在胸前区手术过程中出现并发症。我们报告一例双侧分支胸骨肌的独特病例。每侧的胸骨肌位于乳房和浅筋膜的深面，胸大肌和胸肌筋膜的浅面。每块胸骨肌均分为内侧和外侧束，内侧束大于外侧束。右侧胸骨肌的内侧束大于左侧胸骨肌的内侧束。左侧胸骨肌的外侧束大于右侧胸骨肌的外侧束。左侧胸骨肌的外侧束走行呈弯曲状，上外侧凸，下内侧凹。在其近中部，左侧胸骨肌外侧束分为两个较小的束，中间有一狭窄间隙。我们报告中的左侧胸骨肌是一种具有多个分支的新变异类型，与之前描述的任何分类类型均不相符。在本病例报告中，我们讨论了修改现有胸骨肌分类系统的必要性，以涵盖之前报道的所有类型的胸骨肌，包括该肌肉的分支模式。
