Chronic expanding hematoma is a rare pathology, which has not been previously described as a complication of gunshot injury with retained bullet fragments. Because of the similar characteristics of chronic expanding hematoma to malignancy, it can present a diagnostic challenge for clinicians. Imaging and biopsy evaluation is needed to reach a conclusive diagnosis and implement appropriate treatment. In this case report, we will discuss the development, diagnosis, and management of a chronic superficial cervicothoracic mass in a patient who presented 30 years post-gunshot injury with retained bullet fragments.