The chondroepitrochlearis muscle is a rare anomaly of the pectoralis major crossing over the neurovascular bundle in the axilla. Often associated with other supernumerary muscles like the arch of Langer, it has been reported in the past as a cause of restriction of arm abduction, cosmetic defects and compression of the ulnary nerve. This case report describes the first known vascular complication due to a chondroepitrochlearis muscle, causing intermittent compression of the axillary vein and thrombosis, associated with pain, upper limb lymphedema, and impaired movements. The diagnosis was suspected from the medical history and confirmed by palpation and dynamic ultrasonography. Surgery was performed to divide the muscle slip with the help of lymphofluoroscopy to prevent damage to the lymphatic structures. Pain and impairment of movement disappeared within a few days after surgery and lymphedema decreased significantly.
