(BMJ)—A woman in her 70s who had mastectomy for triple-negative L-sided breast CA 8y prior presented w/ an 8-mo hx of an evolving asymptomatic rash on her trunk and L arm. The rash didn’t improve w/ topical steroids or PO abx. Exam: indurated red plaque on L trunk, neck, and arm and R breast. What’s the dx?