EGFR and nasopharyngeal type undifferentiated carcinoma: Notably, a compound EGFR mutation was detected in four non-adenocarcinoma patients, including two squamous cell carcinomas (SCC, L858R + L858Q and L858R + T790M), one lymphoepithelioma-like carcinoma (LELC, 19Del + L858R) and one adenosquamous carcinoma (ASC, 19Del + T790M).