Clinical and histopathological spectrum of Castleman disease.^1,3 A. Castleman disease (CD) is clinically divided based on LN distribution (multicentric vs unicentric) and etiology (HHV8-associated, POEMS-associated, and idiopathic). Idiopathic MCD (iMCD) is further subdivided based on clinical subtype (TAFRO, NOS, and IPL, which is a recently implicated subtype of NOS). B. CD subtypes are generally distributed across 3 histopathological subtypes: (1) hyaline/hypervascular, (2) plasmacytic, and (3) mixed.