Acquisition of and Amplifications During the Transformation of -Mutated Lung Adenocarcinoma into Squamous Cell Carcinoma: A Case Report.

Histologic transformation from adenocarcinoma to SCLC is a recognized mechanism of resistance in lung cancer. However, the transformation into squamous cell carcinoma is less common, and the associated genomic alterations remain unclear. Here, we present a case of lung adenocarcinoma harboring an EGFR () mutation that transformed into squamous cell carcinoma. Although L858R mutation was detected throughout the transformation, genomic analyses were performed during the disease course, revealing the amplification of and , which have recently been proposed as potential driver oncogenes in lung squamous cell carcinoma. This case report highlights the genomic alterations observed in repeatedly biopsied specimens, along with a review of the relevant literature.