Primary systemic amyloidosis. A case permitting pathological and biochemical investigations.

In this 72-year-old male patient, large amounts of amyloid substances were deposited in the mesenchymal organs, but not in the parenchymal organs. Histochemical and electron microscopic studies revealed large amounts of amyloid substances and amyloid fibrils in the skeletal and smooth muscle tissues. In the skeletal muscle tissues, where large amounts of amyloid substances were deposited, glycosaminoglycan was also markedly deposited, especially chondroitin-4-sulfuric acid. The concentrations of silicon were also markedly increased in the amyloid fibrils. The concentrations of nickel and cobalt were increased but those of zinc were decreased in all organs measured, although both nickel and cobalt in another case of amyloidosis experienced were within normal values.