The
lectin-binding properties of human follicular and
papillary carcinoma were studied histochemically and compared with
lectin binding to normal or goitrous thyroid tissue. Well-differentiated minimally invasive follicular
carcinoma showed a
lectin-binding pattern essentially identical to those of the normal thyroid gland and benign adenomatous lesions. Overtly invasive follicular
carcinoma showed focal reactivity with some
lectins that were nonreactive with normal follicular thyroid cells (Solanum tuberosum and soybean in three of three cases; Ulex europaeus in two of three cases; and Dolichos biflorus, Laburnum alpinum, and peanut in one of three cases). In
papillary carcinomas, the cells lining the papillary structures reacted focally with some
lectins that did not bind to normal thyroid cells (S tuberosum and U europeaus in seven of seven cases; Helix pomatia, Helix aspersa, and soybean in four of seven cases; and peanut, Griffonia simplicifolia, D biflorus, and Vicia villosa in one of seven cases). All these
lectins, as well as those reacting with normal thyroid cells, reacted more strongly with cells of papillary structures than with those forming solid nests and follicles. Despite these
lectin-defined differences in the composition of
glycoconjugates of benign and malignant thyroid cells, the inconsistent and focal nature of the changes precludes the use of
lectins in diagnostic histopathology.