Deepthi Simhadri, Suseelamma D and Praveen Kumar M
Occasionally a vertical strip of muscle is seen at the lateral border of sternum, which is named as ?Rectus sternalis (sternalis) muscle?. This muscle is considered as part of the vertical strip of muscles (strap muscles present from chin to pubis). A rare case of unilateral right sided sternalis muscle was found during routine dissection of human male cadaver at Kamineni Institute of Medical Sciences, Narketpally. The early detection of this variant muscle is necessary for assessing in radiological examination. Here by we report a case of right unilateral rectus sternalis muscle. Knowledge of variations occurring in the muscular system is of great importance to the surgeons and professionals who works with imaging. An unusual variation in chest wall rectus sternalis, it can be confused for a mass on mammography, but confusion revolved by computerised tomography/magnatic resonance imaging. It has unclear embryonic origin, perhaps a remnant of the panniculus carnosus. It is an unusal muscle found occasionally in the anterior part of the thorax. This variation was found in a male cadaver during routine dissection, it belongs to a muscle of pectoral group. It was found in 8% of population. This muscle is called as rectus sternalis, rectus means straight; it lies parallel to the lateral border of sternum on right side, absent in left side. It is an accessory muscle of the chest wall; it is useful for reconstruction of the neck, chest, abdomen, and perhaps even other places. At last, sternalis may be nothing more than misplaced developed muscle tissue, arising from variable sources in a localised region at the anterior thorax, and serving no apparent function but to be fuddle diagnosticians. Therefore, familiarity of the sternalis only broadens the surgeon?s knowledge of variations of chest wall anatomy but also provides reconstructive operations (when present) for wounds in the chest wall as well as adjacent regions. It may be bilateral (or) unilateral. It is a rare variation.