The application of polymerase chain reaction (PCR) to cytological mate
rial represents a promising, relatively noninvasive approach to clinic
al molecular genetic analysis. The detection rate of the t(14;18), the
most common translocation in B-cell lymphomas, which results in rearr
angement of the immunoglobulin heavy chain (IGH) and BCL2 genes, has n
ot been examined in archival cytological smears. We studied 10 cases o
f lymphoma that showed a cytogenetic t(14;18) in a surgical specimen a
nd for which were available both lymphoma DNA from the same specimen a
nd prior or subsequent archival cytological smears, either FNA or exfo
liative, diagnosed as positive for lymphoma. The paired DNA samples, r
espectively extracted from the archival smears and frozen surgical bio
psy tissue, representing clinical intervals of up to 20 mo, were studi
ed in each case by PCR with IGH and BCL2 major breakpoint region prime
rs. In four cases, the same clonotypical PCR product was seen in both
samples. In four other cases, neither sample yielded a PCR product-the
se cases were also negative by Southern blotting using a BCL2 major br
eakpoint region probe. In one case, the PCR product could only be demo
nstrated in DNA from frozen tissue. Finally, in one other case, a PCR
product was only detected in DNA from archival cytological smears. Thu
s, the overall concordance of PCR results in the paired DNA samples wa
s 80%. Our findings suggest that, in cases of B-cell lymphoma previous
ly characterized by PCR, the t(14;18) can be detected in archival cyto
logical smears in the majority of cases, thereby providing valuable da
ta regarding the clonal derivation of metachronous lymphoma samples in
which only cytological material is obtained.