Table 21.

Histological classification

Histological classification	Cases (%)
Squamous cell carcinoma	3990 (84.5%)
Squamous cell carcinoma	973 (20.6%)
Well differentiated	713 (15.1%)
Moderately differentiated	1788 (37.9%)
Poorly differentiated	516 (10.9%)
Adenocarcinoma	239 (5.1%)
Barrett’s adenocarcinoma	109 (2.3%)
Adenosquamous carcinoma	30 (0.6%)
Mucoepidermoid carcinoma	5 (0.1%)
Adenoid cystic carcinoma	3 (0.1%)
Basaloid carcinoma	81 (1.7%)
Neuroendocrine cell tumor	21 (0.4%)
Undifferentiated carcinoma	12 (0.3%)
Other carcinoma	6 (0.1%)
Carcinosarcoma	36 (0.8%)
Malignant melanoma	11 (0.2%)
GIST	1 (0.0%)
Other	46 (1.0%)
Unknown	132 (2.8%)
Total	4722