Pleomorphic Carcinoma With EGFR and Concomitant Mutations Transformed From Lung Adenocarcinoma: A Case Report.

BACKGROUND

Transformation to small cell carcinoma, squamous cell carcinoma, and rarely, pleomorphic carcinoma (PC) has been reported to be found in EGFR-mutated lung cancer with acquired resistance to EGFR tyrosine kinase inhibitors (TKIs). However, evidence for underlying factors including genomic profiles associated with PC transformation has been lacking.

CASE: We report a case of EGFR-mutated lung adenocarcinoma that transformed to PC confirmed by an autopsy after stereotactic radiotherapy and treatment with EGFR-TKIs. Comprehensive genomic profiling of the autopsy tissue revealed BRAF G466A, KRAS L19F, and NF1 Q2324* mutations in addition to EGFR E746_A750del. Anti-cancer treatments with radiation and EGFR-TKIs accompanying these gene alterations might induce the histological transformation and resistance to EGFR-TKIs.

CONCLUSION

This report adds an insight into the involvement of genetic events in histological transformation in EGFR-mutated lung cancer.