ALTERATION OF THE BASEMENT-MEMBRANE IN HUMAN THYROID-DISEASES - AN IMMUNOHISTOCHEMICAL STUDY OF TYPE-IV COLLAGEN, LAMININ AND HEPARAN-SULFATE PROTEOGLYCAN

Basement membrane (BM)) alteration in thyroid diseases was examined by immunohistochemistry using antibodies for the three major BM proteins : type IV collagen, laminin and heparan sulphate proteoglycan. Linear epithelial BMs surrounding follicles accompanied by vascular BMs formi ng loops, similar to those seen in the normal thyroid, were observed i n Graves' disease and adenomatous goitre. Hashimoto's thyroiditis show ed scant epithelial BMs as a result of follicle destruction. In follic ular adenomas, development of epithelial BMs seemed to be related to f ollicle formation; well-developed epithelial BMs were frequently seen in normo- or large-follicular type, whereas trabecular or solid types revealed scant or poorly developed epithelial BMs. Lumpy accumulation of BM proteins was detected in hyalinizing trabecular adenomas. Papill ary carcinomas revealed two different types of papillae; one type cont ained both epithelial and vascular BMs, and the other had only vascula r BMs. Epithelial BMs in invasive areas of papillary carcinoma were di stributed in an irregular, interrupted manner, and were completely abs ent in many foci. Anaplastic carcinomas showed scant or a total loss o f epithelial BMs. These results suggest that alterations of BM in thyr oid diseases clearly reflect their architectural variations, presumabl y in connection with their function and/or biological behaviour.