Next-generation sequencing revealed no detectable mutations in MET, KRAS, NRAS, ROS1, BRAF, or KIT. However, the tumor harbored both high-level ERBB2 (HER2) amplification, with an estimated copy number of 74.5, and a pathogenic ERBB2 point mutation (c.2264T>C, p.L755S, exon 19), detected at a high variant allele frequency of 98.36%. This evidence concerns the gene ERBB2 and neoplasm.