Systemic sarcoidosis first manifesting in a tattoo in the setting of immune checkpoint inhibition

The use of immune checkpoint inhibitors is revolutionising the treatment of cancer. However, their unique toxicity profile is substantially different from what has been observed with traditional chemotherapy, resulting in a novel learning curve for medical oncologists. Early recognition of these toxicities can make a substantial impact in ameliorating these side effects in the oncological and medical-surgical fields. Here, we present a case of Lofgren syndrome sarcoidosis, which first manifested in a tattoo in a patient with metastatic urothelial cancer on therapy with anti-CTLA-4 (ipilimumab) and anti-PD1 (nivolumab).