Pathologic features of plasmacytic histopathologic subtype of unicentric Castleman disease

(A) Reactive lymphoid follicles and interfollicular plasmacytosis are present.
(B) In this field, the reactive germinal center is radially penetrated by a prominent blood vessel.
(C) Sheets of cytologically mature plasma cells are present within the interfollicular region. Hematoxylin and eosin stain.