Suspected immune checkpoint inhibitor-induced pulmonary sarcoid reaction in metastatic renal cell carcinoma.

We present the case of a 50-year-old male patient with metastatic clear cell renal cell carcinoma (mRCC) who developed a diffuse pulmonary opacification and lymphadenopathy during nivolumab maintenance therapy. This was diagnosed as presumed sarcoid granulomatous inflammatory reaction secondary to immunotherapy, which resolved with holding off therapy and the nivolumab was resumed.