Retrospective analysis of 12 Korean patients with paraneoplastic pemphigus.

Paraneoplastic pemphigus (PNP) is a rare, life-threatening, autoimmune, mucocutaneous blistering disease associated with neoplasia. Both humoral and cellular immunity are involved in the pathogenesis of PNP. Characteristically, PNP has a diverse spectrum of clinical and immunopathological features. We retrospectively analyzed 12 Korean patients with PNP who were diagnosed between 1993 and 2011. We performed analysis of the clinical features, clinical outcomes, underlying neoplasia, histological features and laboratory findings. All of the patients except one had severe mucosal involvement. Two patients had only mucosal lesions but no cutaneous involvement was observed. Erythema multiforme or lichen planus-like eruptions rather than bullous lesions were more commonly observed skin rashes. The most common histological features were interface dermatitis and apoptotic keratinocytes. There were associated hematological-related neoplasms in 11 patients, with Castleman's disease (n = 4) as the most frequent. Twelve patients were followed for 5-148 months (mean, 43.0). The prognosis depended on the nature of the underlying neoplasm. Six patients died due to respiratory failure (n = 3), postoperative septicemia (n = 1), lymphoma (n = 1) and sarcomatosis (n = 1). The 2-year survival rate was 50.0%, and the median survival period after diagnosis was 21.0 months. Immunoblotting was performed in 12 patients and autoantibodies to plakins were detected in 11 patients. The results of this study demonstrated the clinical, histological and immunological diversity of PNP. Widely accepted diagnostic criteria that account for the diversity of PNP are needed.