Endoscopic examination of the oesophagus accompanied by histological examination of biopsies or cytological examination of smears enables a confident diagnosis of carcinoma to be established within a period of 24-48 h and in the case of cytology within 15-60 min. Squamous cell carcinoma and adenocarcinoma are easily identified in biopsies or smears taken directly from the lesion. The histopathologist should be alerted to the possible diagnosis of Barrett's adenocarcinoma provided adequate information is given regarding the level of the squamo-columnar junction and the level of the targeted lesion. Unusual tumours are encountered rarely and they include carcinosarcoma, mucoepidermoid carcinoma, adenocystic carcinoma, carcinoid, malignant melanoma, oat cell carcinoma, spindle cell sarcoma, malignant lymphoma, Kaposi's sarcoma, etc. Special stains and multiple levels from the biopsies will be required for accurate identification of these tumours. Dysplasia constitutes a difficult diagnostic problem with reference to its significance regarding surveillance and treatment. Low grade dysplasia represents a recommendation for surveillance provided that the patient is regarded as a good surgical risk if cancer should develop at a later stage. High grade dysplasia is associated with a high risk of invasive cancer and close surveillance is required for the detection and treatment of invasive cancer provided also that the patient is a good surgical risk.