Pectus excavatum is best described as which type of chest wall deformity?

Pectus excavatum is best described as which type of chest wall deformity?

• A. A concave anterior chest wall due to inward displacement of the sternum
• B. A convex protrusion of the sternum
• C. A widened rib cage
• D. A depressed diaphragm due to herniation

Answer: (A)

The concept being tested is how chest wall deformities are defined by the position of the sternum. Pectus excavatum creates a concave, funnel-shaped anterior chest wall because the sternum and adjacent costal cartilage are displaced inward. That inward displacement describes a concave chest, so this option best matches pectus excavatum. The other descriptions fit different conditions: a convex protrusion of the sternum is pectus carinatum; a widened rib cage suggests a barrel chest; a depressed diaphragm due to herniation describes a diaphragmatic hernia.

The concept being tested is how chest wall deformities are defined by the position of the sternum. Pectus excavatum creates a concave, funnel-shaped anterior chest wall because the sternum and adjacent costal cartilage are displaced inward. That inward displacement describes a concave chest, so this option best matches pectus excavatum. The other descriptions fit different conditions: a convex protrusion of the sternum is pectus carinatum; a widened rib cage suggests a barrel chest; a depressed diaphragm due to herniation describes a diaphragmatic hernia.