Table 21.

Histological classification

Histological classification	Cases (%)
Squamous cell carcinoma	4086 (83.2%)
Squamous cell carcinoma	756 (15.4%)
Well differentiated	750 (15.3%)
Moderately differentiated	1989 (40.5%)
Poorly differentiated	591 (12.0%)
Adenocarcinoma	306 (6.2%)
Barrett's carcinoma	118 (2.4%)
Adenosquamous carcinoma	22 (0.4%)
Mucoepidermoid carcinoma	1 (0.0%)
Basaloid carcinoma	86 (1.8%)
Neuroendocrine tumor	1 (0.0%)
Neuroendocrine carcinoma	32 (0.7%)
Undifferentiated carcinoma	8 (0.2%)
Malignant melanoma	16 (0.3%)
Carcinosarcoma	43 (0.9%)
GIST	2 (0.0%)
Adenoid cystic carcinoma	3 (0.1%)
Sarcoma	2 (0.0%)
Other carcinomas	3 (0.1%)
Other tumors	41 (0.8%)
Unknown	140 (2.9%)
Total	4910