BAUHINIA-PURPUREA (BPA) BINDING TO NORMAL AND NEOPLASTIC THYROID-GLANDS

Biotinylated bauhinia purpurea agglutinin (BPA) was studied, using the ABC method, in different thyroid gland conditions (26 follicular aden omas, 39 capillary carcinomas, 15 follicular carcinomas, and 10 normal thyroids), to determine whether specific lectin binding patterns were developed during malignant transformation that could enable the disti nction of carcinoma from adenoma. In normal thyroids, BPA was very rar ely and faintly reactive with follicular cells. In neoplastic conditio ns, BPA binding profiles for follicular adenoma were essentially ident ical to those of normal follicles, whereas BPA unequivocally reacted w ith follicular carcinoma and papillary carcinoma. BPA reacted more str ongly with cells of papillary structures than with those forming solid nests and follicles. In papillary carcinoma, BPA binding was observed mostly in the apical surface and cytoplasm of carcinoma cells, wherea s a diffuse cytoplasmic binding pattern was predominant in follicular carcinoma. Neuraminidase treatment had little or no effect on either n ormal or adenomatous follicular epithelium, whereas in follicular carc inoma, the number of positive cells and the staining intensity was inc reased. These findings suggest that BPA would be useful for the differ ential diagnosis of papillary and follicular carcinomas, and less cons istently so, for differentiating follicular carcinoma from follicular adenoma. Peanut agglutinin with similar sugar specificity was not reac tive with follicular cells either in normal or neoplastic glands.