Partial agenesis of the pectoralis major and minor muscle: A cadaveric case report.

Rationale: The pectoralis major and minor muscles, located in the anterior chest wall, are crucial for upper limb movements.

Patient Concerns: Their nonsyndromic absence is rare but significant for surgical procedures involving the axillary and pectoral regions.

Diagnoses: Ultrasound can confirm the diagnosis and delimit the extent of the muscular abnormality, detect abnormalities of the costal cartilages, among others.