Types of pectus carinatum

Pectus carinatum is a protrusion deformity of the anterior chest wall. The primary forms are:  
(A) Chondrogladiolar prominence, in which the middle and lower portions of the sternum protrude. This is the most common type. 
(B) Chondromanubrial prominence, in which the upper portion of the sternum protrudes anteriorly and the body of the sternum is deviated posteriorly. A final anterior deflection of the distal sternum gives the characteristic Z shape to the sternum on a lateral view. This type represents fewer than 5% of cases.  
(C) Lateral (asymmetric) prominence, which is an asymmetric form of chondrogladiolar prominence. The sternum is typically midline but tilted away from the affected side.
Individual variations of these forms occur, including combinations of chondrogladiolar and chondromanubrial types or combinations of pectus carinatum with pectus excavatum (sternal depression).