Cytokeratin immunolocalization and lectin binding studies in oesophageal squamous dysplasia.

We examined full thickness specimens of oesophageal squamous dysplasia from both cancer-free and cancer patients using immunohistochemical labelling for cytokeratin subtypes 10/13 and 14 and for involucrin, binding studies for various lectins, and PAS/D staining before and after diastase treatment. We studied specimens from patients with oesophageal carcinoma (52 normal epithelia, and 49 with mild, 38 with moderate, and 32 with severe dysplasia), and 32 specimens from cancer-free patients (five normal epithelia and 16 with mild and 11 with moderate dysplasia). Abnormal cytokeratin expression patterns in atypical cells, i.e. both cytokeratin 10/13 and cytokeratin 14 immunoreactivity in the same cells was detected in 41 of 99 specimens with dysplasias in cancer patients. Helix aspersa, Erythrina cristagalli and Robinia pseudoacacia binding was consistently negative in atypical cells in squamous dysplasia. The non-atypical layer of squamous dysplasia, which was morphologically indistinguishable from the corresponding layer of normal oesophageal squamous epithelium, showed abnormal involucrin expression in 39/ 101 specimens, Helix aspersa binding in 74/106, diastase sensitive PAS staining in 52/110, Erythrina cristaglli binding in 28/107, and Robinia pseudoacacia binding in 16/100. There were no significant differences in the expression of these markers in dysplasia between cancer patients and cancer-free individuals with the exception of increased Robinia pseudoacacia binding in the non-atypical layer in cancer-free patients. The results indicate that abnormal patterns of cytokeratin expression and lectin binding occur not only in atypical cells but also in non-atypical cells in oesophageal squamous dysplasia.