Activation of the c-myc Oncogene in a Precursor-B-Cell Blast Crisis of Follicular Lymphoma, Presenting as Composite Lymphoma

B-CELL lymphomas are considered to represent "frozen" stages in the maturation of normal B cells. However, progression to a more malignant histologic form is frequently observed in low-grade lymphomas. 1 Cytogenetic studies have shown that sub-clones can develop during the course of the disease, identifiable by a cascade of multiple recurrent chromosomal abnormalities. 2 , 3 In follicular lymphoma, for example, these abnormalities may be superimposed on translocation t(14;18)(q32;q21), which is found as a marker in about 85 percent of cases and involves the putative oncogene bcl-2. 4 Although several of these aberrations could be correlated with histologic progression, development of leukemia, or a poor . . .