Deletion 7q in B-cell low-grade lymphoid malignancies: A cytogenetic/fluorescence in situ hybridization and immunopathologic study

Ten cases presenting a simple karyotype and del(7q) as a primary event were selected out of 353 patients referred as B-cell low-grade malignant lympho proliferative disorders. Chromosome 7-specific painting probes confirmed th e deletion that was tentatively assigned to bands q31q35. Chromosome 7 was involved in an interstitial deletion in seven cases, in an unbalanced trans location in two cases, and in a ring chromosome in one case. Common clinica l/hematological features included advanced age, marked splenomegaly, and pe ripheral blood monoclonal IgM(D) lymphocytosis, Regardless of morphologic e ntity, most cases shared lymphoplasmacytoid features. Deletion 7q map delin eate a variety of low-grade B-cell lymphoid disorders characterized by a co mmon clinical history and immunopathologic similarities. The cytogenetic pa ttern and the ongoing work on molecular mapping of this deletion suggest th at the loss of a putative tumor-supressor gene at 7q31q32 may constitute an early event in their pathogenesis. (C) Elsevier Science Inc., 1999. All ri ghts reserved.