Unusual Origin of the Posterior Circumflex Humeral Artery: A Case Report.

Prior knowledge of possible variations in human anatomy is essential for basic medical and clinical training. Many surgeons can avoid uncharacteristic situations by having sources and availability of resources that document potential irregularities in human anatomy. In this case, a human cadaver is identified as having an altered origin of the posterior circumflex humeral artery (PCHA). While it usually stems from the axillary artery, this cadaver had a left-sided PCHA originating from the subscapular artery (SSA) and continuing into the quadrangular space. This irregularity of the PCHA from the SSA is not commonly discussed in the literature. Physicians and anatomists need to be fully aware of this possibility and be prepared for any unexpected differences in anatomy during procedures.