Cytogenetic findings in lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia - Chromosomal abnormalities are associated with the polymorphous subtype and an aggressive clinical course

We correlated bone marrow cytogenetic findings with morphologic and immunop henotypic data in 37 patients with lymphoplasmacytic lymphoma (LPL)/Waldens trom macroglobulinemia (WM). Each LPL/WM case was classified as lymphoplasm acytoid (n=18), lymphoplasmacytic (n=10), or polymorphous (n=9) using the K iel criteria. Of 12 cases with chromosomal abnormalities, a single numeric abnormality was present in 4 and a complex karyotype in 8. The most common numeric abnormalities were +5 and -8 in 3 cases each; the most common struc tural abnormality was del(6q) in 6 cases. Cytogenetic abnormalities were si gnificantly less common in the lymphoplasmacytic and lymphoplasmacytoid gro ups (5/28 [18%]) compared with the polymorphous group (7/9 [78%]). Clinical follow-up was available for 28 patients for a median of 36 months. Six (67 %) of 9 patients with aneuploid tumors, including 4 with polymorphous subty pe, subsequently had clinical progression or developed high-grade lymphoma. In contrast, 4 (21%) of 19 patients with diploid tumors, including 1 of po lymorphous type, developed clinical progression or high-grade lymphoma. We conclude that abnormal cytogenetic findings in LPL/WM correlate with the po lymorphous subtype and poor prognosis.