Fig. 2

Case 1: HE staining of core needle biopsy specimen shows there are a few large round or ovoid cells scattered in the inflammatory background (a, inset: low-power view of needle biopsy), which are reminiscent of Hodgkin and Reed-Sternberg cells (b, arrows). Microscopic examination of resected specimens exhibit the classical morphology of hyaline-vascular Castleman’s disease (c, lower left area) and hyperplastic ovoid to spindle cells (c, upper right area). High-power view of figure C shows the transitional zones (d). Multinucleated giant cells and Hodgkin and Reed-Sternberg-like cells are disseminated in the lesions (e, f, arrows). Immunohistochemical staining shows the spindle cells (including some scattered large cells) are positive for CD21 (g), CD35 (h) and D2–40 (i, arrows)