JYC Chan, QU Lee, SC Ling, CK Li, NKC Tse

Abstract

Castleman disease (CMD) is an uncommon lymphoproliferative disorder characterised by hyperplasia of lymphoid tissue. There are three histopathologic types of CMD: hyaline-vascular type, plasma cell type and mixed type. Hyaline-vascular CMD is typically unicentric, while plasma cell CMD tends to be multicentric. In rare occasion, CMD can be associated with paraneoplastic pemphigus (PNP), an autoimmune syndrome which encompasses a multitude of mucocutaneous and systemic clinical features. In children with PNP associated with Castleman disease, they have been reported to have very poor prognosis and high mortality rate as a result of respiratory compromise despite aggressive treatment. We report a case of unicentric, CD-20 positive, hyaline-vascular retroperitoneal CMD presenting with paraneoplastic pemphigus and bronchiolitis obliterans with significant clinical improvement in oral mucositis and the prevention of tumour recurrence, using regular rituximab (375 mg/m²/dose) and 3-day course of pulse methylprednisolone therapy (10 mg/kg/day) after tumour resection.