[Paraneoplastic pemphigus: review of the literature, apropos of a case associated with chronic lymphoid leukemia].

In 1990, Anhalt et al described a newly autoimmune bullous disease: paraneoplastic pemphigus, in five patients. It was characterized by a distinct set of circulating autoantibodies from those in the sera of patients with pemphigus vulgaris and superficial pemphigus. We report a 71 year-old man with chronic lymphocytic leukemia of 4 years duration who developed a severe mucocutaneous eruption with clinical and immunofluorescence findings of pemphigus vulgaris evolving into an oral bullous lichen planus presentation. Evaluation of his serum confirmed the presence of autoantibodies specific for paraneoplastic pemphigus by indirect immunofluorescence on rat-bladder and immunoprecipitation. Subsequently, additional cases have been reported in the literature. All occurred in patients with various neoplastic conditions. These patients present with polymorphous skin lesions and severe erosive oral disease. Histologic examination shows interface dermatitis and keratinocyte necrosis in addition to acantolysis. Direct immunofluorescence may reveal deposition of immunoglobulin and/or complement at the basement membrane as well as deposition on epithelial cell surfaces. Circulating IgG anti-cell-surface antibodies are detectable with both stratified and stratified epithelia as substrates. These antibodies immunoprecipitate a complex of four desmosomal proteins, including desmoplakin I (250 kDa), the bullous pemphigoid antigen (230 kDa), desmoplakin II (210 kDa) and a 190 kDa antigen.