Cytogenetic, in sits hybridization, and molecular studies were perform
ed in a case of T-cell-rich B-cell lymphoma. Demonstration of Ig gene
rearrangements for both heavy and light chains confirmed the B-lineage
restriction of the neoplastic cell population. Moreover, as expected
in B-cell malignancies, all abnormal karyotypes showed a 14q+ chromoso
me marker involving 14q32. The origin of the extra material on the der
ivative 14q+, as defined by chromosome painting with a library for chr
omosome 11, and Southern blotting for c-myc and bcl-2 rearrangements,
remains unknown.