Fig. 5
From: Paraneoplastic pemphigus and Castleman’s disease: a case report and a revision of the literature
A Lymphoid follicle with atrophic germinal centre and numerous radially oriented penetrating hyalinized blood vessels (“lollipop” appereance). Note the perifollicular areas of sclerosis and the sclerotic blood vessels. B Lymphoid follicle with atrophic germinal centre and expanded mantle zone arranged in concentric rings (“onion skin” appearance). C CD20 immunostain shows many B follicles with atrophic germinal centres. D IgD immunostain shows the follicles mainly composed of mantle B-cells with a concentric arrangement. E CD21 immunostain shows the atrophic germinal centres mainly composed of hyperplastic follicular dendritic cells