S1.
WHO classification of esophageal carcinomas (referring to WHO classification of tumors of the digestive system. 2010)
| Histological type | ICD-O code |
| Squamous cell carcinoma | 8070/3 |
| Rare variants: | |
| Verrucous carcinoma | 8051/3 |
| Spindle cell squamous cell carcinoma | 8074/3 |
| Basaloid squamous cell carcinoma | 8083/3 |
| Adenocarcinoma | 8140/3 |
| Mucoepidermoid carcinoma | 8430/3 |
| Undifferentiated carcinoma | 8020/3 |
| Neuroendocrine neoplasms: | |
| Neuroendocrine tumors (NET) | |
| NET G1 | 8240/3 |
| NET G2 | 8249/3 |
| Neuroendocrine carcinomas (NEC) | 8246/3 |
| Small cell carcinoma | 8041/3 |
| Large cell neuroendocrine carcinoma | 8013/3 |
| Mixed adenoneuroendocrine carcinoma | 8244/3 |