In an 87-year-old male cadaver received through the Gift Body Program at Saint Louis University School of Medicine, a common arterial trunk arose from the third part of the left axillary artery (AA) that divided into the subscapular artery (SA) and a common stem for the deep brachial artery (DBA), the anterior humeral circumflex artery (AHCA), and the posterior humeral circumflex artery (PHCA). Both the SA and AHCA appeared normal. The PHCA traveled through the quadrangular space and gave off the radial collateral artery (RCA) in the posterior arm which anastomosed with the radial recurrent artery. The DBA traveled through the triangular interval and continued as the middle collateral artery (MCA) in the posterior arm to anastomose with the interosseous recurrent artery. Lastly, the medial and lateral cord contributions to the median nerve formed posteriorly to the AA. Knowing anatomical variation of the AA has clinical and embryological significance.
