LECTINS IN THE VULVA - II - VULVAR INTRAEPITHELIAL NEOPLASIA AND SQUAMOUS-CELL CARCINOMA

This study used lectins as histologic probes to determine the cell sur face oligosaccharide expression in different grades and types of vulva r intraepithelial neoplasia (VIN). Lectin binding patterns in metastas izing and non-metastasizing squamous cell carcinomas (SCCs) of the vul va were also compared to correlate lectin binding patterns with metast atic potential and other clinical/tumor characteristics. Twenty cases each of VIN epithelium, metastasizing SCC, and non-metastasizing vulva r carcinoma were randomly chosen from the pathology archives. Sixteen lectins were used to probe individual terminal oligosaccharide residue s in formalin-fixed, paraffin-embedded tissue specimens from these cas es through an indirect immunohistochemical technique. There were no di fferences in lectin binding patterns between the different histologic subtypes of VIN. In addition, there were no consistent differences bet ween metastasizing and non-metastasizing primary tumors and no major d ifferences in staining patterns between nodal metastases and the corre sponding primary tumors. Furthermore, there was no identifiable correl ation between lectin binding patterns and subsequent survival or local or regional recurrence; however, lectin staining of invasive tumor ce lls did appear to &e related to local invasiveness. In addition, posit ive PNA binding was found to be a constant finding in each of the VIN and invasive SCC cases, confirming that the T-antigen becomes unmasked during the process of vulvar carcinogenesis. However, poorly-differen tiated areas consistently showed absent lectin binding, suggesting los s of specific glycosyl transferase activities. In addition, the blood group ''A'' antigen appears to be lost during the process of tumorgene sis, although the blood group ''O'' antigen appears to be preserved.