Spontaneous Remission of Everolimus-Induced Interstitial Lung Disease in Metastatic Renal Cell Carcinoma : An Autopsy Case Report

Interstitial lung disease (ILD) is a common side effect of the mechanistic target of rapamycin inhibitor everolimus. Most cases of everolimus-induced ILD are mild and reversible. As per guidelines, even if Common Terminology Criteria for Adverse Events grade 1 or 2 everolimus-induced ILD occurs, either continuation of everolimus without dose reduction or readministration at a low dose is possible. However, the pathophysiology of everolimus-induced ILD is unknown. We present a case of everolimus-induced ILD with spontaneous remission during treatment in a patient with metastatic renal cell carcinoma. At autopsy, there was no evidence of remodeling or chronic inflammation in the lungs. Cryptogenic interstitual pneumonia and broncholitis obliterans with organizing pneumonia can be suspected as a pattern of mild everolimus-induced ILD. This case report provides evidence that everolimus-induced ILD is reversible fromthe pathological perspective.