Table 1 Summary table of sternalis muscle of the anterior thoracic wall.
From: Sternalis muscle: an underestimated anterior chest wall anatomical variant
Etiology | Congenital |
|---|---|
Incidence | Cadavers: 1-18.2%. Mammograms: 0.019%. Multidetector CT: 6.2% |
Gender ratio | Slightly higher incidence in females |
Appearance risk factors | Unknown - Uninvestigated |
Symptoms | Usually asymptomatic. Minor aesthetic complains and a subject with areola-nipple deviation has been reported so far |
Treatment | No treatment needed in asymptomatic cases. In reported symptomatic case surgical removal or release was recommended |
Findings on imaging | Mammogram: Irregular structure medially on the craniocaudal projection. Plain X-ray: Not visible. CT/MRI: Flat and parallel to the sternum structure overlying pectoralis major muscle. 3D reconstruction from CT or MRI: Very helpful in cases of narrow strip-like sternalis muscle |
Differential diagnosis | Alterations in electrocardiogram. In imaging: may mimic breast carcinoma, fat necrosis, abscess, diabetic mastopathy, hematoma, lymphadenitis, surgical scar, extra-abdominal desmoids tumor, medial insertion of the pectoralis muscle, granular cell tumor, sclerosing adenositis |
Points of surgical interest | Can be used as an individual or conjoined sternalis-pectoralis muscle flap for breast reconstruction after mastectomy, as a flap in the reconstruction of the anterior chest wall and head & neck |