Fig. 2

Case 2. Chest CT showing a primary lesion in the right lower lobe (a), a 10-mm nodule in the right S6, and right middle lobe atelectasis due to bulky hilar and subcarinal lymph nodes (b) before afatinib treatment. Chest CT showing the marked regression of both the primary tumor (c) and lymph node metastases, with the disappearance of middle-lobe atelectasis (d) after afatinib therapy. Histological findings (hematoxylin-eosin staining) showing the prominent proliferation of fibroblasts (e); residual viable tumor cells were found in a small area of the primary lesion (f)