Expression of mucin type carbohydrates may supplement histologic diagnosis in oral premalignant lesions.

Recent studies have shown that changes within membrane bound carbohydrates may be essential for cellular differentiation and malignant transformation. We have therefore, by means of immunohistochemistry, studied the expression of T/Tn related (Thomsen-Friedenrich) carbohydrates in 13 oral lesions with squamous cell dysplasia. The epithelial grade of dysplasia was graded as mild, moderate or severe. The following carbohydrate structures were studied: Tn, T, mucintype 3 chain H, and the sialylated derivates, sialosyl-Tn and sialosyl-T. In general, short structures were detected on the basal cells and longer structures on the more mature spinous cells. In many cases, this sequential expression was more disturbed with increasing grade of epithelial dysplasia. However, our results also showed that some lesions with the same grade of epithelial dysplasia showed different carbohydrate expression. These findings indicate that expression of carbohydrates may supplement histologic diagnosis in the evaluation of the prognosis of premalignant lesions.