Rectus Sternalis: A Case Report

  • Rupali A Gajare Assistant Professor, Department of Anatomy
Keywords: Dissection, Mammography, Sternum


The sternalis is an anatomical variant of anterior chest wall muscle. It occurs either unilateral or bilateral. It lies in the anterior chest
wall, superfi cial to the sternal origins of the pectoralis major muscle. The sternalis usually courses longitudinally adjacent to the
sternum and does not cross the midline. In the Department of Anatomy, during routine dissection of thoracoabdominal region of
a 49-year-old male, a distinct, separate fusiform muscular mass about 12 cm long was found in the left hemithorax, covered by
superfi cial fascia and located anterior to the pectoralis major muscle. The details are given in this case report. There is a lot of debate
on the origin of the muscle. This muscle can be misdiagnosed on routine mammography as a breast mass. It can play an important
role in reconstruction fl ap surgeries. Such anatomical variation should be kept in mind during surgical procedures and diagnosis.

Author Biography

Rupali A Gajare, Assistant Professor, Department of Anatomy

Rajiv Gandhi Medical College, Kalva, Maharashtra, India


1. Shankar VV, Rajan R. Rectus sternalis muscle - A rare anatomical variant.
Natl J Clin Anat 2013;2:41-3.
2. Blees G. A peculiar type of sternalis muscle. Acta Morphol Neerl Scand
3. Bailey PM, Tzarnas CD. The sternalis muscle: a normal fi nding encountered
during breast surgery. Plast Reconstr Surg 1999;103:1189-90.
4. Vandeweyer E. The sternalis muscle in head and neck reconstruction. Plast
Reconstr Surg 1999;104:1578-9.
5. Arráez-Aybar LA, Sobrado-Perez J, Merida-Velasco JR. Left musculus
sternalis. Clin Anat 2003;16:350-4.
6. Loukas M, Bowers M, Hullett J. Sternalis muscle: a mystery still. Folia
Morphol (Warsz) 2004;63:147-9.
7. Scott-Conner CE, Al-Jurf AS. The sternalis muscle. Clin Anat
8. Harish K, Gopinath KS. Sternalis muscle: importance in surgery of the
breast. Surg Radiol Anat 2003;25:311-4.
9. Bradley FM, Hoover HC Jr, Hulka CA, Whitman GJ, McCarthy KA,
Hall DA, et al. The sternalis muscle: an unusual normal fi nding seen on
mammography. AJR Am J Roentgenol 1996;166:33-6.
10. Standring S. Gray’s Anatomy. 39th ed. London: Churchill; 1973.
11. Larsen WJ, editor. Human Embryology. 2nd ed. Edinburgh:
Churchill- Livingstone; 1997.
12. Jeng H, Su SJ. The sternalis muscle: an uncommon anatomical variant
among Taiwanese. J Anat 1998;193:287-8.
13. O’Neill MN, Folan-Curran J. Case report: bilateral sternalis muscles with a
bilateral pectoralis major anomaly. J Anat 1998;193:289-92.
14. Morrita M. Observation of muscles sternalis and musculi pectoralis in
mammals and a morphological interpretation of essence of musclus
sternalis. Acta Anat Japan 1944;22:357-66.
15. Kida MY, Izumi A, Tanaka S. Sternalis muscle: topic for debate. Clin Anat
16. Young Lee B, Young Byun J, Hee Kim H, Sook Kim H, Mee Cho S, Hoon
Lee K, et al. The sternalis muscles: incidence and imaging fi ndings on
MDCT. J Thorac Imaging 2006;21:179-83.
17. Gupta M, Harjeet. Bilateral sternales in relation to body of sternum. Nepal
Med Coll J 2004;6:62-3.
18. Jelev L, Georgiev G, Surchev L. The sternalis muscle in the Bulgarian
population: classifi cation of sternales. J Anat 2001;199:359-63.