Severe Pneumonitis after Nivolumab Treatment Accompanied by Acute Pulmonary Embolism in a Patient with Lung Adenocarcinoma

A 75‐year‐old Han Chinese man presented with a 1‐day history of acute shortness of breath. His medical history included lung adenocarcinoma, hepatitis B virus (carrier), hypertension, previous deep vein thrombosis (DVT), smoking for 45 years, and drinking for 35 years. He underwent dissection of his right upper and middle lobes and mediastinal lymph nodes 5 years previously and developed pleural and multiple pulmonary metastasis 3 months postoperatively. Molecular tests for epidermal growth factor receptor, KRAS, and anaplastic lymphoma kinase rearrangement were negative. He received 33 cycles of chemotherapy and 2 sessions of radiotherapy for lung metastases. However, he still developed bilateral lung metastases and multiple thoracic and lumbar vertebral metastases. Six weeks before the current presentation, he received nivolumab (3 mg/kg every 2 weeks, three cycles).