Scleroderma-like skin changes induced by checkpoint inhibitor therapy.

Checkpoint inhibitors have emerged as beneficial therapies in many different types of malignancy. The most common toxicities of checkpoint inhibitors are immune-related adverse events (irAEs). As clinical experience with these agents increases, more irAEs have been described. We report a case of scleroderma-like skin changes induced by checkpoint inhibitor therapy. A 61-year-old man was treated with nivolumab for oligometastatic renal cell carcinoma. He initially tolerated the therapy well, but after 16 treatments he began experiencing skin thickening and edema of the abdominal wall, which progressed down the trunk and legs. A punch biopsy revealed epidermal attenuation overlying thickened dermal collagen with entrapment and displacement of the eccrine coils and loss of periadnexal adipose tissue. Focally increased plasma cells were present near the junction of the dermis and subcutaneous adipose tissue. Loss of CD34 staining was seen throughout the dermis. These findings were consistent with a diagnosis of scleroderma. After discontinuation of nivolumab and initiation of steroid therapy, the patient's symptoms significantly improved. This case is among the first reports of scleroderma-like changes induced by a checkpoint inhibitor.