Serial imaging before and during immunotherapy in a patient with metastatic lung adenocarcinoma. A right lower lobe primary tumor, extensive thoracic adenopathy, and a sternal metastatic lesion were present at diagnosis of stage IV disease. The primary tumor and metastases, except for the sternal lesion, were stable over the first 3 months on platinum-based chemotherapy and immunotherapy. Over the next 7 weeks, however, there was disease progression at all sites. Repeat biopsy demonstrated high grade NSCLC with necrosis.