Castleman disease (CD) is a benign lymphoproliferative disorder that may present as a localized or multicentric form (see these terms). The clinical manifestations are heterogeneous, ranging from asymptomatic discrete lymphadenopathy to recurrent episodes of diffuse lymphadenopathy with severe systemic symptoms.

Drusen (singular, 'druse') are tiny yellow or white accumulations of extracellular material (lipofuscin) that build up in Bruch's membrane of the eye.