An analysis of the diagnostic accuracy of endoscopic biopsy and cytology in the detection of oesophageal malignancy.

The role of combined cytohistological examination in the differentiation of benign from malignant oesophageal mucosal lesions was studied in 331 patients. Malignancy was confirmed by specimen histopathology in 58 patients. Both endoscopic biopsy and cytology were positive in 41 (71%) patients. Endoscopic biopsy alone suggested malignancy in 10 cases (17%) while cytology was positive after negative biopsy in seven (12%). Cytology yielded four false positive and 10 false negative results giving a sensitivity level of 81%, a specificity of 98% and a positive predictive value for oesophageal malignancy of 92%. Histology on the other hand yielded one false positive and seven false negative results providing a sensitivity of 87%, a specificity of 99% and a positive predictive value of 96%. No patients were left undiagnosed using both diagnostic modalities; cytology increased the diagnostic yield from 87% to 100%. Exfoliative cytology was most valuable in the diagnosis of tumours of the lower one-third of the oesophagus where seven of 31 malignancies (23%) were identified by this method alone (P less than 0.05). Neither the histological type of the tumour nor the morphological appearance was found significantly to affect the diagnostic yield (P greater than 0.05). We conclude that cytological examination should be standard practice in the investigation of oesophageal lesions.