Paraneoplastic pemphigus: A report of three cases including one long-term survivor

Background: Paraneoplastic pemphigus is a newly described autoimmune disease characterized by painful mucosal ulcerations and polymorphous skin lesions in association with an underlying neoplasm. All reported patients with an associated malignant neoplasm have had a poor prognosis. Objective: We present three new cases of paraneoplastic pemphigus associated with a malignant neoplasm and further characterize this disease. Methods: We used clinical criteria, histologic and immunopathologic examinations, and im-munophenotyping to characterize this disease. In addition, we performed immunoprecipita-tion studies with extracts of radiolabeled human keratinocytes to characterize the antigens to which patient serum binds. Results: All three patients had clinical, histologic, and immunopathologic findings that were strongly suggestive of paraneoplastic pemphigus. Their sera immunoprecipitated a complex of four polypeptides from human keratinocyte extracts with molecular weights of 250, 230, 210, and 190 kd, confirming the diagnosis of paraneoplastic pemphigus. The 250, 230, and 210 kd antigens comigrated with desmoplakin I, the 230 kd buhous pemphigoid antigen, and desmoplakin II, respectively. Lymphocyte immunophenotyping revealed large populations of monoclonal CD19⁺, CD5⁺ B cells in two cases. Although two of the patients died, one patient is alive and well 2 years after the diagnosis of paraneoplastic pemphigus. Conclusion: We report three cases of paraneoplastic pemphigus. One patient is alive and well 2 years after diagnosis, which suggests that a subgroup of patients may have a more benign course.