We present a rare case of postradiation lichen planus confined to the irradiated breast area following radiotherapy for breast cancer. The clinicopathological features and temporal association supported the diagnosis of radiation-induced lichen planus, with complete resolution after corticosteroid treatment. This case illustrates postradiation lichen planus as a distinct immune-mediated dermatosis and suggests that ionizing radiation may not only cause direct tissue damage but also influence local immune regulation, potentially predisposing to cutaneous autoimmunity.
Gabilondo et al. (Fri,) studied this question.