Cutaneous Urothelial Carcinoma Presenting as Rash in a Patient with Small Bowel Obstruction

Summary: Urothelial carcinoma rarely metastasizes to the skin, but when it does, it is associated with a poor prognosis. We present a case of cutaneous urothelial carcinoma in a patient admitted for small bowel obstruction. Dermatology was consulted to evaluate a progressive skin eruption in an 80-year-old female with past medical history significant for invasive urothelial carcinoma with plasmacytoid features diagnosed four years prior. She had been treated with transurethral resection, ileal conduit, and pembrolizumab and was in her normal state of health until 6 weeks prior, when she began experiencing fatigue, emesis, abdominal distention, and weight loss. She was admitted for a suspected small bowel obstruction. Around the time her bowel symptoms began, she developed a rash on the left medial knee which gradually spread up the leg onto the groin and lower abdomen. She denied associated pain or pruritus. Examination was significant for erythematous to violaceous retiform patches on the left thigh and multiple erythematous to violaceous indurated plaques, some with overlying nodularity on the left groin and lower abdomen. A biopsy of the lower abdomen revealed poorly differentiated carcinoma consistent with the patient’s urothelial carcinoma. She was discharged home to hospice care.