Elevation of Serum Carcinoembryonic Antigen Concentration Caused by Everolimus-Induced Lung Injury: A Case Report

A 66-year-old woman underwent right nephrectomy for treatment of renal cell carcinoma (RCC). Two years later, she underwent wedge resection of the right lung for treatment of metastatic RCC and primary adenocarcinoma of the lung. She began oral sorafenib for the remaining nodules of the left lung, which were suspected to be metastatic RCC. Two years later, the sorafenib was changed to everolimus because of slight enlargement of the left pulmonary nodules. The carcinoembryonic antigen (CEA) concentration then increased to 25.7 ng/mL, and chest computed tomography (CT) revealed ground-glass opacities (GGO) in the bilateral lungs. Everolimus-induced lung injury was suspected, and she discontinued the everolimus. Two months later, the serum CEA concentration decreased to almost within the reference range at 5.9 ng/mL, and the GGO disappeared on chest CT. In conclusion, we encountered a patient who developed an elevated serum CEA concentration caused by everolimus-induced lung injury.