Drug-induced Sarcoid-like Reaction Presenting as Fascitis

Drug-induced sarcoid-like reactions (DISRs) present complex challenges in clinical management. The most common presentation in FDG-PET/CT scan is bilateral symmetrical lymphadenopathy, and occasionally spleen and bone involvement. DISR presenting as fasciitis/ myofasciitis is extremely rare. We will discuss pre-chemo, post-chemo, and follow-up FDG-PET/ CT scans, exhibiting DISR-induced fasciitis and resolution of findings after cessation of immunotherapy. How to diagnose and manage DISR is still debatable. Histologic confirmation or short interval follow-up scans with resolution findings can lead to the diagnosis, depending on the severity of symptoms, cessation of therapy or continuation of therapy is instituted.