[A case of retroperitoneal Castleman's disease with paraneoplastic pemphigus]

Paraneoplastic pemphigus is a rare autoimmune bullous dermatosis, which is caused by potential neoplasm, especially the Castleman's disease. Castleman's disease associated with paraneoplastic pemphigus is misdiagnosed frequently and easily in clinical practices. Furthermore, it is reported that the mortality rate for this disease is very high. Bronchiolitis obliterans is the most common complication and the most important cause of death. There was a female patient presenting recalcitrant mucocutaneous erosions, ulcers and scattered erythemas in the body. The patient was diagnosed and treated for pemphigus vulgaris with little success in Xiangya Hospital, Central South University in January 2015. Further investigations confirmed the diagnosis of paraneoplastic pemphigus with retroperitoneal tumor. Subsequently, the patient was treated with tumor resection in combination with intravenous immunoglobulin and corticosteroids. The pathology revealed that it was the Castleman's disease. Her mucocutaneous performance recovered obviously and the bronchiolitis obliteran did not appear in the follow-up. Castleman's disease associated with paraneoplastic pemphigus should be considered when mucosal and skin lesions showing no improvement under corticosteroids. Early and complete removal of the tumor together with immunotherapy could be beneficial to the patient's prognosis.