49. A 61-year-old woman presents to the pain clinic with a chief complaint of left shoulder and arm pain for 3 years after undergoing radiation therapy for breast cancer. Physical examination reveals lymphedema of the left axilla with noticeable skin changes. Examination of the left supraclavicular area precipitates a sharp pain that radiates down her left arm. Which of the following is likely diagnosis for her clinical presentation ? (A) Radiation-induced plexopathy (B)Tumor metastasis (C) Reflex sympathetic dystrophy (D) Cervical radiculopathy (E) Thrombangiitis obliterans