Polymerase chain reaction analysis of immunoglobulin gene rearrangement incutaneous lymphoid hyperplasias

Background: The differential diagnosis of cutaneous lymphoid hyperplasia an d B-cell lymphoma ma!, be difficult. Whether the detection of clonal immuno globulin gene rearrangement in the cutaneous lesion is predictive of a mali gnant outcome remains controversial. We therefore studied cases of cutaneou s lymphoid hyperplasia by polymerase chain reaction analysis. Design: Retrospective study of patients seen between 1988 and 1996. Setting: Two dermatology university departments. Patients: Twenty-four patients with cutaneous lymphoid hyperplasias were in cluded according to clinical, histopathological and immunophenotypic criter ia. Main Outcome Measures: Clinical, histopathological, and laboratory findings . Results: There were 13 men and 11 women (mean age, 49 years) who presented with erythematous or violaceous papules or nodules. The lesions were unique in 13 cases and multiple in II cases. All patients had immunochemical evid ence of a mixed T- and B-cell infiltrate with polytypic B cells. Polyclonal ity was demonstrated in 23 patients, whereas a dominant B-cell clone was de tected in 1 patient. No lymphoma developed during the follow-up (median, 4 years). In the same period, we studied 53 cases of B-cell lymphomas. Thirty -five (66%) of the 53 cases had a detectable clonal immunoglobulin gene rea rrangement. Conclusions: In the majority of our cases, polyclonality demonstrated by po lymerase chain reaction analysis was in accordance with;ht diagnosis of cut aneous lymphoid hyperplasia. In 1 of the 23 patients, the presence of a B-c ell clone could be evidenced. This fact did nut modify the treatment as the re were no histological or immunophenotypic signs suggestive of a lymphoma.