A study of histologic and immunophenotypical staining patterns in cutaneous lymphoid hyperplasia

BackgroundCutaneous lymphoid hyperplasia (CLH) is generally classified according to clinicopathologic entities or put into broad spectrums of B-cell or T-cell predominance or co-dominance.ObjectiveWe sought to discern histologic features and immunohistochemical staining patterns in CLH that may form a basis for a histologic classification system.MethodsWe studied the clinical, histologic, immunophenotypical, and molecular characteristics of 24 consecutive patients with CLH.ResultsThe 24 cases were classified according to characteristic histologic features and immunophenotypical staining patterns as follows: presence of germinal center (GC) cell clusters forming well-defined lymphoid follicles (n = 10); presence of clusters of GC cell clusters not forming well-defined lymphoid follicles (n = 6); persistent arthropod assault type CLH (n = 1); CLH with a prominent histiocytic component (n = 4); and CLH without specific histologic and immunophenotypical features, that is, nonspecific mixed T-cell and B-cell CLH (n = 3). Most of the CLH cases did not demonstrate clonal T-cell receptor and/or immunoglobulin heavy chain gene rearrangements except for 3 cases in which the long-term follow-up was uneventful.LimitationsThere were a limited number of cases in our study.ConclusionsA classification based on characteristic histologic features and immunophenotypical staining patterns, along with pertinent clinical and molecular data, may enhance the diagnosis of CLH.