CORRELATION OF PCR-DETECTED CLONAL GENE REARRANGEMENTS WITH BONE-MARROW MORPHOLOGY IN PATIENTS WITH B-LINEAGE LYMPHOMAS

Bone marrow biopsy is the conventional staging and posttherapy evaluat ion method for assessing marrow involvement by lymphoma. Polymerase ch ain reactions (PCR) for antigen receptor rearrangements have the poten tial to increase the detection of minimal de rees of marrow involvemen t. The present study is a concurrent morphologic and PCR evaluation of 225 staging or posttherapy marrow biopsies from 127 patients with B-l ineage non-Hodgkin's lymphoma. The biopsies were morphologically categ orized into four groups: group 1 (positive for lymphoma), 60 biopsies (27%); group 2 (suspicious for lymphoma), 20 biopsies (9%); group 3 (l ymphocytic lesions of indeterminate biology), 22 biopsies (10%); and g roup 4 (negative for lymphoma), 123 biopsies (54%). Molecular studies were performed on concurrently obtained aspirates and used consensus i mmunoglobulin-heavy-chain (IgH) and IgH/bcl-2 gene PCR primers. A mole cular clone was detected in 53 of the 225 aspirates (24%): group 1, 34 aspirates (57%); group 2, five aspirates (25%); group 3, one aspirate (5%): and group 4, 13 aspirates (11%). A PCR-positive aspirate was pr esent in 47% of follicular lymphomas, 58% of diffuse large cell lympho mas, and 72% of the other lymphomas in the group I specimens. Morpholo gy or PCR was positive in 79 of the 225 cases (35%). The molecular det ection of clonality in the aspirate DNA from cases with positive morph ologic findings was lower than anticipated. The discordance between mo rphology and PCF, results may be related to sample variation between t he trephine biopsy and aspirate, a failure to aspirate sufficient lymp homa cells, or insufficient primer homology for amplification. UNA ext racted from trephine sections may provide results more concordant with morphology, because PCR detected a clone in 10 of 11 DNA specimens ex tracted from trephine biopsies with positive morphologic findings and PCR negative aspirates.