Abstract
Azan-Mallory stain of thyroidal colloid and its relation to the functional state of the thyroid were studied by animal experiments and on clinical materials. Thyroidal colloid shows basophilia and acidophilia in elevated and resting state of thyroid function, respectively. The acidophilic colloid itself represents basophilia at its margin adjacent to the follicular cells. In case of adenoma, well differentiated follicles contain acidophilic colloid, and less differentiated, basophilic colloid. In case of adenocarcinoma, both acidophilic and basophilic colloids are irregulary admixed in a single follicle.
