The breakdown of histological subtypes other than adenocarcinoma for patients who were TTF-1-negative was as follows: 14 NOS, 2 pleomorphic carcinomas, and 1 LC-NEC in the non-PEM− group; 1 NOS, 3 pleomorphic carcinomas, and 1 LC-NEC + adenocarcinoma mixed type in the non-PEM+ group; 3 NOS and 1 LC-NEC in the PEM− group; 2 NOS, 1 pleomorphic carcinoma; and 1 pleomorphic carcinoma + adenocarcinoma mixed type in the PEM+ group. Here, TTF1 is linked to laryngotracheoesophageal cleft.