Pathology - Castleman disease. Mediastinal mass in a younger woman. Histologic Features of Castleman disease, hyaline vascular type - Increase in paracortical blood vessels - Germinal center 'twinning' = rnost specific feature - Hyalinized germinal centers with penetrati ngvessels - Suggestion of mantle zone 'onion skinning' - Michael Cascio, M.D. @mjcascio #Castleman #disease #Pathology #Smear #Microscopy #Clinical