NGS as an auxiliary tool for differential diagnosis of solid tumors: a clinical case and literature review

Molecular genetic profiling of solid tumors by next-generation sequencing (NGS) is widely used to select targeted therapy. At the same time, with rare exceptions, NGS has not proven to be a reliable tool for differential diagnosis of diseases. However, some types of tumors have specific somatic mutations, and their detection can serve as a reason for clarifying the diagnosis using standard methods. An example of such mutations are specific abnormalities in the EGFR gene, which occur exclusively in lung cancer. In the described clinical case, the patient was diagnosed with skin adenocarcinoma. Molecular genetic profiling revealed an EGFR exon 19 deletion mutation, which served as a reason for additional histological studies and revision of the diagnosis in favor of lung adenocarcinoma, and demonstrates the possibility of using the results of molecular profiling as an auxiliary method for differentiating cancer subtypes.