We describe a case of single synchronous facial cutaneous metastasis from intestinal ASC showing KRAS and CTNN1B mutations both on primary and metastatic lesions.
PIK3CA mutations occurred more frequently in SCC than AC (25% vs. 11%, P=0.025), whereas KRAS mutations occurred more frequently in AC than SCC (24% vs. 3%, P<0.001) and ASC (24% vs. 3%, P<0.001).
Our findings suggest that EGFR/KRAS mutations do not occur in pure pulmonary SQCC, and occasional detection of these mutations in samples diagnosed as "SQCC" is due to challenges with the diagnosis of AD-SQC and adenocarcinoma, which can be largely resolved by comprehensive pathologic assessment incorporating immunohistochemical biomarkers.
EGFR mutations occur in adenosquamous carcinoma in the same percentages as in conventional adenocarcinoma in the Western population.KRAS mutations are less common.