Nivolumab-Induced Pneumonitis in Patient With Metastatic Melanoma Showing Complete Remission on 18F-FDG PET/CT

Abstract

A 49-year-old patient with metastatic melanoma was treated with nivolumab (Opdivo). An early 18F-FDG PET/CT after 2 cycles showed a progressive metabolic disease. A 4-month optimal follow-up 18F-FDG PET/CT showed a complete metabolic response. The treatment was stopped after 22 cycles because of immunotherapy-related pneumonitis. After discontinuation of treatment, PET/CT examinations demonstrated a metabolic complete remission during 2 years. The metabolic pattern on early PET was suggestive of pseudoprogression, which is a rare phenomenon reflecting an activation of inflammatory cells within the tumor microenvironment causing lesions to increase in size and to accumulate FDG until a sufficient immune response is developed.

Immunotherapy (Cemiplimab)-Induced Bullous Pemphigoid

“…Treatment with corticosteroids and pausing cemiplimab for 1 cycle led to a significant improvement of the skin lesions, allowing successful continuation of immunotherapy afterwards. Immunotherapy-associated adverse effects comprise a large array of nonspecific features visible on 18 F-FDG PET/CT, 2 for example, sarcoid-like reaction, 3–5 hypophysitis, 6,7 thyroiditis, 8 pneumonitis, 9,10 colitis, 11 adrenalitis, 12 or pancreatitis 13,14 . Although the more frequent adverse events are well-known today, other less common adverse events, as in our case, may impose diagnostic challenges, particularly with regard to the discrimination from metastases and progressive disease.…”