Sweet's syndrome under ipilimumab therapy and a brief comparison of the cases in literature.

Ipilimumab is an anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) antibody. Ipilimumab has shown improvement in overall survival in patients with advanced melanoma. Because ipilimumab activates the immune system against the tumor, ipilimumab is associated with adverse events related to immune system activation. Immune-associated side effects are frequently seen in the gastrointestinal system and skin. Sweet's syndrome (SS) is an uncommon inflammatory disorder. Some drugs or malignancy can cause SS. Only a few case reports have been reported of ipilimumab-associated SS. A 53-year-old female with metastatic melanoma was treated with ipilimumab. After the fourth cycle, she developed painful lesions on her legs and hands. The pathologic biopsy of the lesions revealed neutrophilic dermatosis consistent with SS. Herein we report a case presented with SS under ipilimumab therapy. Melanoma patients treated with ipilimumab can develop SS. The clinicians should be aware of this condition.