EGFR, KRAS, BRAF and HER2 testing in metastatic lung adenocarcinoma: Value of testing on samples with poor specimen adequacy and analysis of discrepancies

Tumor cell content is a crucial parameter for molecular analysis rather than the type of specimen or the DNA quantity. Discrepancies in molecular testing results are rare but might suggest the presence of another tumor type, the emergence of another clone or a molecular testing in a sample with low cell content.