ABSTRACT
Metastasis to the bone is a known risk of breast cancer, with the humerus being the most common upper extremity site of metastases, with most lesions located at the humeral diaphysis. We present a unique case of proximal humeral metastasis involving the epiphysis secondary to primary invasive ductal carcinoma in a middle-aged Caucasian female. It is important to have a high degree of suspicion for metastasis when musculoskeletal pain occurs in breast cancer patients, as it may be masked by common, degenerative conditions about the shoulder girdle. When humeral metastases involve the epiphysis, treatment options are complicated by its location, which jeopardizes the integrity of articular cartilage and the function of the shoulder girdle. External beam irradiation provides pain control in a non-invasive manner, sans surgical risks. Surgical intervention will vary depending on the characteristics of the bony lesion, but the use of endoprosthetics has emerged as the most effective option for restoring range of motion and pain control with acceptable rates of implant survival.