Cutaneous Disorders Associated with Castleman's Disease.

Castleman's disease is a rare disease of the lymph nodes and related tissues, presenting as angiofollicular or giant lymph node hyperplasia. Although various skin manifestations have been reported to occur in Castleman's disease, a comprehensive study of cutaneous disorders in Castleman's disease is lacking. Therefore, the aim of this study was to investigate Castleman's disease-associated cutaneous disorders. The medical records of 57 patients with Castleman's disease who visited our hospitals from January 2007 to May 2018 were analysed retrospectively. Patients were classified according to the presence of skin involvement. Plasma variant-type Castleman's disease and multicentric Castleman's disease were more commonly found in patients with Castleman's disease with a cutaneous disorder than in those without a cutaneous disorder. In addition, the skin disorders were classified according to pathomechanisms: immune complex-related (paraneoplastic pemphigus, xanthogranulomas), cytokine-related (vasculitis-like lesion, cherry angioma, hyperpigmentation), and non-specific (pruritus). This study builds on previous case reports of cutaneous disorders in Castleman's disease and proposes a new classification system.