What is A 66-year-old woman presents with a 6-month history of scaling and abnormal pigmentation of the skin. Her past medical history is significant for the treatment of thyroid cancer 1 year ago. Biopsy of lesional skin shows atrophy of the epidermis and dense fibrosis of the dermis, which displays dilated superficial blood vessels. These pathologic findings are most likely caused by previous exposure to which of the following? and explain in detail?
Ionizing radiation administered for the treatment of cancer must first traverse the skin, leading to radiation dermatitis. Skin biopsy shows atrophy of the epidermis and dense fibrosis of the dermis, which displays dilated superficial blood vessels. In some cases, persistent ulcers require skin grafts. The other choices do not cause these dermal findings.Diagnosis: Radiation injury