Paraneoplastic Pemphigus Presenting as a Lichen Planus Pemphigoides—like Eruption

Background.—Paraneoplastic pemphigus refers to a specific disease entity in which neoplasia is associated with severe mucosal ulceration and polymorphous cutaneous eruptions, sometimes resembling erythema multiforme. Direct immunofluorescence and indirect immunofluorescence on standard substrates are similar to pemphigus vulgaris; however, paraneoplastic pemphigus serum uniquely binds to all epithelia and has distinctive immunoprecipitation characteristics. Observations.—A 63-year-old woman with chronic lymphocytic leukemia developed a severe, mucocutaneous, vesiculobullous eruption with the clinical and histopathologic characteristics of lichen planus pemphigoides evolving into a Stevens-Johnson—like presentation and the immunofluorescence findings of pemphigus vulgaris. Evaluation of her serum confirmed the presence of autoantibodies specific for paraneoplastic pemphigus by indirect immunofluorescence and immunoprecipitation criteria. Conclusion.—The spectrum of paraneoplastic pemphigus must now be expanded to include cases that present clinically and histologically as a lichen planus pemphigoides— like eruption.