Fig. 4.

Two representative cases of patients with necrosis in a lung lesion, a positive sequencing only, and a complication of an invasive diagnostic test. (A-D) In a 78 years old woman, pneumothorax (arrowhead) occurred after percutaneous needle biopsy (PCNB) of a lung lesion (arrow) in outer location on lingula segment of the left upper lobe with necrosis. The patient was diagnosed with stage I lung adenocarcinoma and epidermal growth factor receptor (EGFR) exon 19 deletion was detected by EGFR PCR method. Result of BW sequencing also showed an EGFR exon 19 deletion mutation, E746_A750del. The patient underwent radiosurgery rather than surgical resection considering her old age and low performance status. (A) axial view (B) coronal view (C) PCNB (D) pneumothorax occurred after PCNB

(E-H) In a 51 years old woman, pulmonary hemorrhage (arrowhead) with hemoptysis developed after PCNB of a lung lesion (arrow) in mid location on right lower lobe with necrosis. The patient was diagnosed with stage II lung adenocarcinoma and EGFR exon 20 insertion was detected by EGFR PCR method. Result of BW sequencing also showed an EGFR exon 20 insertion mutation, D770_N771insSVD. The patient underwent lobectomy. After 1 year, recurrence of lung cancer was observed and the patient received amivantamab, a target agent for EGFR exon 20 insertion mutation, and the partial response of lung lesions was observed thereafter. (E) axial view (F) coronal view (G) PCNB (H) pulmonary hemorrhage developed after PCNB.