PMC9035954_01
CT views of metastatic disease with large right pleural effusion (*), pleural thickening, and intra-abdominal adenopathy (white arrow) at diagnosis. CT, computed tomography.
cro-0015-0285-g01.jpg
PMC9035954_01_cro-0015-0285-g01.jpg
F1
A chest X-ray revealed a large right-sided pleural effusion, with subsequent computed tomography scan of the thorax, abdomen/pelvis confirming the presence of the pleural effusion and additional multiple lung nodules, extensive upper retroperitoneal lymphadenopathy, and small volume ascites (Fig. 1).
Schematic outlining the mutation of the atypical K757N mutation in relation to other common sensitizing mutations in EGFR-positive lung cancer.
cro-0015-0285-g02.jpg
PMC9035954_01_cro-0015-0285-g02.jpg
F2
Targeted next-generation sequencing (NGS) revealed the absence of KRAS and BRAF mutations but was positive for an exon 19 missense mutation where a lysine residue was substituted with asparagine at position 757 (K757N) at 49% allele frequency (Fig. 2).