Fig. 1

Imaging, pathologic and molecular characteristics of the multifocal adenocarcinoma. Computed tomography showing a solid nodule in the LUL (a) and a Ground-Glass Nodule in the LLL(F) . Microscopic showed mixed solid and cribriform patterns in the LUL nodule (b) and a Papillary Pattern in the LLL nodule (g) (HE; original magnification, × 100). c ALK protein was positively expressed in LUL nodule (c) but negative for LLL nodule (h) (immunohistochemistry; original magnification, × 100). The break-apart fluorescence in situ hybridization assay verified ALK receptor tyrosine kinase gene (ALK) rearrangement in LUL nodule (d) but not in LLL nodule (i) (FISH; original magnification, × 1000). EGFR mutations were not found in LUL nodule (e), but a deletion of EGFR exon 19 presented in LLL nodule (j) by the ARMS-PCR method. NGS test confirmed the ALK fusion(E13;A20, relative abundance 6.42%) in LUL nodule (k) and EGFR 19 exon deletion (c.2240_2248delTAAGAGAAG, p.L747_A750delinsS, relative abundance 15.58%) in LLL lesion (l)