In June 2019, a 70-year-old woman was referred to our hospital due to pain in the chest and back. Chest computed tomography (CT) revealed a tumor in the upper left lobe involving the left hilum and mediastinum (Fig. 1A, E). Moreover, multiple metastatic sites were suspected at mediastinal lymph nodes, ribs, liver, and left adrenal gland (Fig. 1I). The pathological result of biopsy of liver metastases showed adenocarcinoma originating from the lung. After complete inspection, the patient was diagnosed as stage IV NSCLC (adenocarcinoma). The gene detection of biopsy tissue by amplification refractory mutation system (ARMS) showed deletion in exon19 at the EGFR gene. Rearrangement in the anaplastic lymphoma kinase (ALK) and c-Ros oncogene 1 receptor kinase (ROS1) fusions were negative. Afterwards, the patient started to receive targeted therapy of icotinib (125 mg, per os, t.i.d.). Re-examination by radiological scans in 1-month intervals demonstrated the primary lung cancer mass had no obvious change but the remaining metastasis of the liver, adrenal gland, and mediastinal lymph nodes had decreased in size significantly (Fig. 1B, F, J). According to the Response Evaluation Criteria in Solid Tumors v.1.1 (RECIST 1.1), a stable response in pulmonary lesions and partial response in extrapulmonary metastasis were confirmed. In November 2019, the patient received two cycles of chemotherapy with pemetrexed on the basis of targeted therapy. However, the pulmonary tumor remained stable after combination therapy (Fig. 1C, G). In order to clarify the different responses between the primary pulmonary lesion and other metastasis, electronic bronchoscope was performed, which revealed an ulcer at the left main and superior lobar bronchus. Also, a biopsy specimen revealed chronic inflammation with necrosis. A nucleic acid test of respiratory pathogens in the sputum was positive for mycobacterium TB complex. The patient was then transferred to the TB hospital. GeneXpert MTB/RIF detection showed a positive result but a TB smear was negative. After the diagnosis of TB in January 2020, the patient received anti-TB treatment with an HRZE fixed dose combination composed of isoniazid, rifampicin, pyrazinamide, and ethambutol for 2 months. Meanwhile, she continued targeted therapy. In May 2020, chest and abdomen CT demonstrated that the pulmonary mass had shrunk significantly but metastases of the liver and adrenal gland had enlarged markedly, which was assessed as disease progression (Fig. 1D, H, L). Re-biopsy of the liver metastasis showed the same pathological pattern as before. The gene detection by ARMS revealed deletion in exon19 and a point mutation in exon20 (T790M) at the EGFR gene. Hence, the patient received osimertinib treatment.