Diffusely Scattered Macules Following Radiation Therapy

Abstract

A 41-year-old woman was referred to dermatology by her radiation oncologist for evaluation of a rash on the right breast at the site of prior radiation therapy of 4 to 6 weeks' duration. Approximately 2 years prior, the patient was diagnosed with triple-negative invasive ductal carcinoma of the right breast. She was treated with neoadjuvant chemotherapy, bilateral simple mastectomies, and 28 doses of adjuvant radiation therapy. Thirteen months after completing radiation therapy, the patient noted the onset of asymptomatic freckles on the right breast that had appeared over weeks and seemed to be multiplying. Physical examination at the time of dermatology consultation revealed multiple diffusely scattered, brownishred, 3-to 5-mm macules concentrated on the right breast but also involving the right supraclavicular and right axillary areas, abdomen, and thighs. WHAT'S THE DIAGNOSIS? a. cutaneous mastocytosis b. eruptive seborrheic keratoses c. fixed drug eruption d. lichen planus pigmentosus e. solar lentiginosis