Introduction: The
differential diagnosis of B-
cell lymphoproliferative processes remains a challenge for
pathologists ,
dermatologists and
oncologists , despite advances in
histology ,
immunohistochemistry and
molecular biology .
Objective: Evaluate
aid and limitations of clonality
analysis in the
diagnosis of primary cutaneous
B-cell lymphomas and B-
cell pseudolymphomas .
Methods: This study included 29 cases of B-
cell lymphoproliferative processes classified as primary cutaneous
B-cell lymphomas (13), B-
cell pseudolymphomas (6) and inconclusive cases (10) using
histology and
immunohistochemistry . The clonality
analysis was performed by
polymerase chain reaction analysis of
immunoglobulin light chain and heavy chain rearrangements.
Results: DNA quality was shown to be generally poor; eight samples were inadequate for
polymerase chain reaction analysis . The results showed monoclonality in eight of the primary cutaneous
B-cell lymphomas and polyclonality in four of the B-
cell pseudolymphomas . In addition, monoclonality was shown in two of the inconclusive cases by
histology and
immunohistochemistry , demonstrating the utility of
polymerase chain reaction as an ancillary diagnostic tool for primary cutaneous
B-cell lymphomas .
Discussion: The low quality
DNA extracted from these cases demanded the use of an IgH protocol that yielded small fragments and IgK. Both
methods used together improved
detection .
Conclusion: Use of the two
protocols ,
immunoglobulin heavy chain FR3-trad and
immunoglobulin light chain -Kappa Biomed
protocols for clonality
analysis improved diagnostic accuracy.