Two cases of everolimus-associated interstitial pneumonia in patients with renal cell carcinoma.

We herein report two cases of everolimus-associated interstitial pneumonia in patients with renal cell carcinoma. A 68-year-old Japanese man (case 1) was admitted to our hospital because of progressive dyspnea, left infiltration and consolidation on chest radiographs. He had started receiving everolimus (10 mg daily) three months before the admission for the treatment of recurrent renal cell carcinoma. Bronchoalveolar lavage fluid taken from his left B(4) showed a marked increase of lymphocytes (42.9%). An organizing pneumonia pattern of everolimus-associated interstitial pneumonia was strongly suspected radiologically, and treatment with high-dose corticosteroids, discontinuation of everolimus and oxygen support was started. The treatment was successful, and the patient recovered with only minor pulmonary fibrotic changes in the left lower lobe. A 57-year-old Japanese man (case 2) was referred to our department for the evaluation of interstitial pneumonia. He had started to receive everolimus (10 mg daily) four months previously. Chest CT demonstrated interstitial pneumonia predominantly in bilateral lower lobes, with small pulmonary metastatic nodules. His pulmonary complications were spontaneously resolved eight days after the discontinuation of everolimus. To the best of our knowledge, Case 1 is the first reported case of successfully treated organizing pneumonia pattern of interstitial pneumonia with acute respiratory failure induced by everolimus in Japan.