Bone marrow aplasia and Ewing's sarcoma occuring prior to stem cell transplant

The association of secondary malignancies with bone marrow aplasia after bone marrow transplant is a known entity. We report a 19 year old man who was diagnosed as having bone marrow aplasia. The initial and subsequent evaluations of his bone marrow and blood showed normal chromosomes, normal mitocycin C stimulation, and normal serum acid hemolysis test. In March, 1995, he was treated with antilymphocyte globulin (ALG), cyclosporine (CSA), glucocorticosteroids (G) and gmcsf. His marrow quickly showed trilineage recovery. However by February, 1996, his peripheral blood counts and bone marrow again indicated marrow failure. The very hypocellular marrow showed only a rare CD34 positive cell and the marrow lymphocytes were entirely T suppressor cells (CD3, CD8). Again the bone marrow responded to ALG, CSA, G, and gcsf, but by the summer of 1997 his platelet ct was 43K and absolute neutrophil count (ANC) 600. In the weeks prior to the initially scheduled stem cell transplant, the patient "injured" his right elbow. Subsequent evaluation of the right elbow demonstrated a Ewing's sarcoma/PNET by histology and cytogenetics (46, XY, t(11;22)(q24; q21) of the right distal humerus. This is the first known report of bone marrow aplasia with the association of Ewing's sarcoma occuring prior to stem cell transplant. We speculate that the use of ALG, CSA and G down regulated his helper lymphocyte population and placed him at an increased risk for the development of a malignancy.