BCL1 major translocation cluster gene rearrangements had been previously documented in two MCL patients; the other MCL and the two B-SLL, showed no detectable BCL1 or cyclin D1 rearrangements.
The t(11;14) breakpoint junctions involving the bcl-1 major translocation cluster were amplified by PCR in 4 of 11 (36%) MCL cases and in none of the MCL-PC or SLL cases.
All samples showed JH rearrangement, and three samples (two diffuse small lymphocytic lymphomas and one diffuse large cell lymphoma probably transformed from a diffuse small lymphocytic lymphoma) demonstrated rearranged bcl-1 sequences.