Bayrd, Edwin D.

Abstract Five cases of erythroleukemia of the acute or incomplete variety form the basis of this report. Four of the patients were women. The ages of these five patients ranged from 19 to 73 years at time of admission to the Mayo Clinic. Studies were made on the blood and peripheral marrow for varying periods throughout the course of the disease. All five patients had anemia and extreme immaturity of the erythrocytes in the peripheral blood and bone marrow. Leukopenia was eventually present in four cases as was thrombopenia. Splenectomy was performed on one patient. One patient lived six years after the condition developed, two died within thirteen months of the time of diagnosis, one was not followed, and the fifth was still living at last report. Relatively few cases of erythroleukemia have been reported in the literature and most of those reported have been cases of the chronic variety. The erythrocytic picture in the chronic variety differs from that in the acute variety. In the acute type acute erythremia is associated with leukemia and in the chronic type polycythemia is associated with it. Either the erythrocytic abnormality or the leukocytic may appear first. Our studies and those reported in the literature suggest excessive activity of the blast cell in two directions.

Abstract Amyloid fibrils consist in part of immunoglobulin light chains. Because light chains are synthesized by plasma cells, it seems reasonable to treat patients with amyloidosis with alkylating agents. Two patients who had primary amyloidosis and were treated with melphalan subsequently developed a rapidly fatal acute leukemia. Since melphalan may play a significant role in the development of acute leukemia, we suggest that alkylating agents not be used in the treatment of patients with amyloidosis without full consideration of risks involved, particularly until it has been proved that these drugs are beneficial.

Abstract Bone marrow studies of multiple myeloma revealed, in some cases, a conspicuous proliferation of "lymphoid" cells, virtually indistinguishable by light microscopy from those seen in lympho-proliferative disorders. Electron microscopy demonstrated a variety of cells ranging from typical lymphocytes to cells with plasmocytoid features. Between these two types of elements there were cells with intermediate characteristics. In addition, in several cases of myeloma the presence of fixed reticuloendothelial cells and "reticular" plasma cells (or reticulum cells with plasmocytic features) was frequently noted. The presence of reticulum cells and lymphocytes and of cells apparently "intermediate" between these cellular elements and plasma cells, as judged from electron microscopic observations, is suggestive morphologic evidence of a phenomenon of cell transformation and evidence of a mixed cell proliferation in certain cases of multiple myeloma.

Abstract Peripheral blood smears were studied in 25 selected cases of infectious mononucleosis. In 7 the onset was acute and the course severe, in 6 the onset was acute and the course mild, in 6 the onset was gradual and the course severe, and in 6 the onset was gradual and the course mild. The predominance of any of the various types of lymphocytes of infectious mononucleosis was not noted to bear any relationship to the clinical course, although type III lymphocytes and granulocytic immaturity may be more frequently seen when the onset is acute. When toxic changes are present in the granulocytes, the clinical course is likely to be severe.

Abstract Generalizing, it can be said that the pathologic cells seen in smears of the bone marrow in multiple myeloma resemble the plasma cell and vary from the very anaplastic and immature cell to the well-differentiated and almost characteristic plasma cell. The feature which the "myeloma" cell shares with the plasma cell is the abundant, granular, basophilic cytoplasm which tends to be fragile and undergo the same degenerative changes in each; namely, the formation of Russell bodies and vacuolization. Fairly frequently a perinuclear clear area or Hof is present and the nucleus tends to be eccentrically placed. Cytoplasmic extensions or pseudopodia may also be seen in either case, but they occur more often and more dramatically in instances of multiple myeloma. Multinucleated cells are commonly seen. In addition, myeloma-plasma cells will often have a large clear nucleolus and a leptochromatic nucleus and will exhibit a tendency to the formation of isolated areas of condensed chromatin. Cytoplasmic extrusions, free cytoplasmic bodies, occasionally complete with Russell bodies and vacuoles are almost universally present. All cases were of the plasma cell type; there was no exception. In these cases, the myeloma-plasma cell constituted from 2.5 to 96 per cent of the leukocytic elements present. The opinion was expressed that all so-called types of multiple myeloma are merely variations in differentiation of this same cell. It was noted that anaplasia, hypernucleation and lack of plasma cell predominance in certain cases were diagnostic pitfalls. Additional evidence was adduced to confirm the reticulo-endothelial origin of the myeloma-plasma cell. It was further observed that certain prognostically valuable information could be gleaned from a careful review of the cytologic characteristics in these cases.