A 47-year-old woman with a history of inflammatory breast cancer presented with a 2- to 3-week history of asymptomatic lesions of the right chest and axilla. The cancer in her right breast had been treated 3.5 years earlier by bilateral mastectomy, right axillary lymph node dissection, tamoxifen therapy, and radiotherapy to the right chest. Physical examination revealed grouped vesicles, some on a background of mild erythema, and scattered, flesh-colored, flat-topped papules overlying the patient's mastectomy scars and radiation field on the right chest and axilla (Figure 1). The left chest and axilla were unaffected. Results from a Tzanck preparation, direct fluorescent antibody testing for herpes simplex virus and varicella zoster virus, and viral cultures were negative. A punch biopsy specimen was obtained from the right axilla (Figure 2 and Figure 3).