An Axillary Arch Muscle Variant with Potential Neurovascular Implications

The axillary arch (AA), also known as Langer’s axillary arch, is the most common muscular variation encountered in the axilla. It typically arises from the latissimus dorsi and traverses the axillary fossa, often crossing anterior to the neurovascular structures before inserting into the pectoralis major or surrounding fascia. Although frequently asymptomatic, this variant may cause neurovascular compression or complicate surgical procedures involving the axilla. During routine cadaveric dissection, an axillary arch muscle was identified in a 97-year-old male donor. The muscular slip originated from the medial border of the latissimus dorsi and inserted into the trilaminar tendon of the pectoralis major, passing anterior to the axillary artery and median nerve. No additional muscular variations were observed. This report highlights the anatomical features and clinical relevance of the axillary arch and emphasizes the importance of recognizing this variation to avoid diagnostic confusion and surgical complications.