MULTIPLE LYMPHOID NODULES IN BONE-MARROW HAVE THE SAME CLONALITY AS UNDERLYING MYELODYSPLASTIC SYNDROME RECOGNIZED WITH FLUORESCENT IN-SITUHYBRIDIZATION TECHNIQUE

Benign nodular lymphoid lesions are not rare in the bone marrow of pat ients with myelodysplastic syndrome (MDS). Herein, we report a case of MDS with clonal lymphoid aggregates in the bone marrow but without ev idence of systemic lymphoma. The case of a 71-year-old man was evaluat ed for cytopenia, His bone marrow was Initially hypocellular, with 10% blasts and a few small lymphoid aggregates. The diagnosis of refracto ry anemia with excess blasts was made. The disease progressed graduall y, and he received erythropoietin and granulocyte colony-stimulating f actor for a short time. Forty-two months later, acute leukemia (M1) de veloped, with 60% to 70% blasts in the bone marrow. The bone marrow al so showed large aggregates of lymphocytes. Immunohistochemical study o f these cells in the nodular lesions showed 50% CD3+ and 50% CD20+. Cy togenetic and molecular genetic studies revealed monosomy 7 and T- and B-cell clonal gene rearrangement, Fluorescent in situ hybridization s tudy with centromere-specific probes of a bone marrow specimen showed monosomy 7 in both nodular lymphoid lesions and surrounding bone marro w cells, indicating that both processes originated from the same abnor mal pluripotential progenitor. (C) 1998 Wiley-Liss, Inc.