Cutaneous manifestations of lupus erythematosus: A practical clinicopathologic review for pathologists.

Accurate diagnosis of connective tissue diseases is often challenging and relies on careful correlation between clinical and histopathologic features, direct immunofluorescence studies, and laboratory workup. Lupus erythematosus (LE) is a prototype of connective tissue disease with a variety of cutaneous and systemic manifestations. Microscopically, cutaneous LE is classically characterized by an interface dermatitis, although other histopathologic patterns also exist depending on the clinical presentation, location, and chronicity of the skin lesions. In this article, we review the clinical, serologic, histopathologic, and direct immunofluorescence findings in LE-specific and LE-nonspecific skin lesions, with an emphasis on lesser known variants, newly described features, and helpful ancillary studies. This review will guide general pathologists and dermatopathologists in accurately diagnosing and subclassifying cutaneous LE.