Amyloidosis and multiple myeloma. A reevaluation using a control population

To explore the possible influence of multiple myeloma on age-related amyloid accumulation, the frequency, extent and distribution of amyloid deposition in 35 patients who died of multiple myeloma was compared to that observed in 138 patients of comparable age but without myeloma (controls). The presence of multiple myeloma did not appear to enhance the development of age-related amyloid. Amyloid deposition in the patients with myeloma could be distinguished from that in the patients without myeloma by the occasional finding of amyloid in the bone marrow. In addition, material having the tinctorial and ultrastructural characteristics of amyloid was found in the renal tubular casts of 15 patients with myeloma but in none of the controls. The results suggest that although the appearance of amyloid in certain locations appears to be characteristic of multiple myeloma, the presence of amyloid in the heart or vascular system, even in considerable amounts, in a patient with multiple myeloma does not necessarily imply that the two conditions are related.