Atypical Amyloidosis Associated With Nonthrombocytopenic Purpura and Plasmocytic Hyperplasia of the Bone Marrow

1. Two cases of chronic nonthrombocytopenic purpura of unusual distribution, associated with generalized amyloidosis and plasma cell hyperplasia of the bone marrow, are described in detail with their postmortem findings.

2. Grossly recognizable amyloid was present in the antemortem sternal marrow aspirates of both patients.

3. Skin sections in each patient revealed hemorrhages associated with marked amyloid deposition in the dermis and blood vessel walls. It is postulated that this purpura was of vascular type.

4. The diagnosis of the underlying pathology in both patients was made possible by marrow aspiration. The importance of proper use of marrow particle smears in the diagnosis of plasma cell disturbances in the bone marrow is emphasized.

5. The difficulty in differentiating plasma cell myeloma from other causes of plasma cell hyperplasia of the marrow is clearly documented in this report.