Castleman's disease: atypical manifestation in an 11-year-old girl.

Castleman's disease (angiofollicular lymphoid hyperplasia) is a rare lymphoproliferative disorder that can be found in both nodal and extranodal sites. It is classified histologically as the more common hyaline vascular variant, a plasma cell variant, or a mixed form. The hyaline vascular variant is typically characterized by a benign clinical course with no constitutional symptoms other than localized pressure from the mass. We report an atypical case of the hyaline vascular variant with constitutional symptoms that have been clinically associated with the aggressive plasma cell variant. Diagnosis was confirmed histopathologically after surgical resection, which was curative and resulted in resolution of all symptoms. This case broadens our understanding of Castleman's disease as a part of the spectrum of lymphoproliferative and inflammatory diseases. Furthermore, it supports recent studies suggesting that systemic pathogenicity is related to associated cytokine dysregulation and highlights the need to include Castleman's disease in the differential diagnosis of pediatric lymphoproliferative disorders.