Histochemical study on systemic amyloid microdeposits with special reference to parathyroid intrafollicular deposits

Summary This study was carried out in order to define the histochemical behaviour of the substance present in follicles of normal parathyroid glands obtained at routine autopsies. It was noticed that these follicles with typical amyloid staining properties are constantly present in old persons; furthermore the amyloid in question presents histochemical characteristics which identify it as Apudamyloid.With this in mind we studied the possible, concomitant, systemic, amyloid microdeposits; we noticed that intrafollicular Apudamyloid of the parathyroid gland is often encountered together with immune deposits which are sometimes present in the same gland though not necessarily in the follicles.We are grateful to Mr. L. Bortoletto for his technical assistance.