Abstract

Lichen sclerosus and morphea are chronic inflammatory disorders of unknown etiology. The vast majority of cases of lichen sclerosus involve genital skin, while the extragenital form is seen in only 10-15% of cases. Morphea occurs more commonly on the trunk but the two may co-exist as overlap lesions. There are rare case reports of radiation-induced morphea/extragenital lichen sclerosus overlap. We present the case of a 78-year-old female with a new lesion of the left breast that had started as erythema and scaling with intermittent formation of a blood-filled blister. She was diagnosed with ductal adenocarcinoma of the left breast 11 years prior and underwent partial mastectomy and adjuvant radiation with 5 years of aromatase inhibitor therapy. A recent mammogram was unremarkable. On physical exam, there was a well-demarcated erythematous and hemorrhagic-crusted plaque involving the left nipple, areola, and adjacent breast. The clinical suspicion was of Paget’s disease. Two punch biopsies demonstrated well-developed features of lichen sclerosus/morphea overlap with epidermal atrophy, interface vacuolar change, and extensive sclerosis extending deep into the dermis. She was treated with tacrolimus 0.1% ointment and showed a marked response. This case illustrates an unusual presentation of radiation-induced morphea, with overlapping extragenital lichen sclerosus, presenting with features suspicious for Paget’s disease. It highlights the necessity of biopsy to exclude Paget’s disease, as well as chronic radiation dermatitis and lymphedema, in the setting of previous adenocarcinoma and radiotherapy.