Aims-To evaluate the rapid detection of various forms of monoclonal B
cell proliferations by using the polymerase chain reaction (PCR) to id
entify clonal immunoglobulin heavy chain genomic rearrangements. Metho
ds-Thirty four B cell lymphomas defined by morphology, immunophenotypi
ng, and positive immunoglobulin heavy chain gene rearrangements detect
ed by Southern blot analysis were examined. An additional 22 cases rep
resenting miscellaneous lymphoproliferative and non-lymphoproliferativ
e disorders were also studied. Results-Monoclonal rearrangements were
identified in 19 (56%) cases of B cell lymphoma. The method was less s
ensitive in the detection of follicular centre cell lymphomas (15 of 2
8, or 54%) than non-follicular centre cell lesions (four of six, or 67
%). Monoclonal rearrangement was not identified in 19 control cases, i
ncluding T cell lymphomas, Hodgkin's disease, reactive lymphadenopathy
and metastatic carcinoma. Three cases showed positive immunoglobulin
gene rearrangement by PCR but were negative on Southern blotting. Two
of these cases had definite clinical, morphological, and immunophenoty
pic evidence of monoclonal B cell proliferation suggesting that PCR co
uld, on occasion, pick up cases missed by Southern blotting and that t
he two methods are complementary in clonal lymphoproliferative disease
diagnosis. The third case represented a ''false positive'' PCR reacti
on involving a colonic adenocarcinoma. Conclusions-PCR analysis, using
the primer sequences outlined in this study, will detect about 55% of
clonal lymphoproliferative proliferations with increased sensitivity
for non-follicular centre cell lesions. With these levels of detection
in mind, this testing strategy can still be especially useful in case
s which prove diagnostically problematic with standard morphological a
nd immunophenotypic analysis, and in instances where the quantity and
type of diagnostic material is limiting (needle aspirates and cellular
fluids).