CLONAL ANALYSIS BY POLYMERASE CHAIN-REACTION OF B-CELL LYMPHOMA WITH LATE RELAPSE - A REPORT OF 5 GASES

BACKGROUND. Little is known about the clonal heterogeneity of non-Hodg kin's lymphoma between presentation and relapse, although several such reports have been published on acute lymphoblastic leukemia. METHODS. We examined five patients with B-cell lymphoma who relapsed more than 5 years after initial presentation. Formalin fixed, paraffin embedded tissues were analyzed for clonal immunoglobulin heavy chain gene rear rangement by the polymerase chain reaction (PCR) and sequencing of the PCR products. Four specimens retained the original histologic type, b ut one showed histologic transformation from diffuse large cell lympho ma to follicular small cleaved cell lymphoma. RESULTS, Although the si ze of the PCR products looked identical on the gel between presentatio n and relapse in all patients, only three of the four specimens that r etained the original type had identical gene rearrangements at both pr esentation and relapse. One of these four and the fifth specimen showe d novel gene rearrangements. CONCLUSIONS. This study suggests that lat e relapse lymphoma may present as a new clone. Sequencing of the PCR p roducts is important in the evaluation of clonal heterogeneity. (C) 19 96 American Cancer Society.