Tumid lupus erythematosus: criteria for classification with immunohistochemical analysis.

OBJECTIVE

To define comprehensive criteria for the classification and differential diagnosis of tumid lupus erythematosus (LE).

METHODS

A prospective study of patients fulfilling the classical description of tumid LE was performed. Clinical evaluation, histopathologic and direct immunofluorescence analyses of skin specimens, and serologic evaluation were conducted. The inflammatory cell infiltrate was quantitatively investigated by immunohistochemical analysis of fresh frozen skin specimens using multiple lymphocytic markers.

RESULTS

Fifteen patients were followed for a mean of 7 years. Smooth, indurated, nonscarring, pink to violaceous papules, plaques, or nodules, devoid of surface changes were distributed on sun exposed sites. The mean lesion duration was 2 years, female:male ratio was 8:7, and racial distribution was 11 white, 2 Hispanic, and 2 African American patients. Histopathologic findings included a superficial and deep, perivascular, and frequently periadnexal infiltrate of lymphocytes, mucin deposition throughout the dermis, and absent to focal dermal-epidermal junctional involvement. Direct immunofluorescence immunoreactants and low titer antinuclear antibodies were variably present. Immunohistochemical findings included a predominance of pan-T cell marker CD3-expressing (78.0% +/- 6.3%) T lymphocytes. Most were CD4 expressing (82.7% +/- 8.0%) helper T cells; a minority were CD8 expressing (31.3% +/- 14.0%) cytotoxic T cells. The CD4:CD8 ratio was 3.1 (+/-1.3):1. One patient developed systemic LE and one a discoid LE lesion.

CONCLUSION

Comprehensive clinical, histopathologic, and immunohistochemical criteria for the classification of tumid LE are proposed that differentiate tumid LE from other cutaneous disorders that may be clinically and histologically indistinguishable. The chronic, benign course indicates that tumid LE be classified as a form of chronic cutaneous LE, although it may be a cutaneous feature of systemic LE.