Nowak V, et al. - Using immunohistochemistry and consensus scoring criteria as used for immunoglobulin 4-related disease (IgG4-RD), IgG4+ plasma cells per high-power field (HPF) and the ratio of IgG4+ vs IgG+ plasma cells (IgG4/IgG ratio) in lymph node biopsies of 24 people with nodular-sclerosing Hodgkin lymphoma (NSHL) were ascertained in order to discover the actual amount of IgG4+ plasma cells in NSHL and its likelihood to be wrongly diagnosed in routine clinical practice. In NSHL vs follicular hyperplasia, greater numbers of IgG4+ plasma cells were noted. In NSHL, the mean count of IgG4+ plasma cells per HPF differed exceedingly (3–88) with expanded numbers of IgG4+ plasma cells observed around areas of fibrosclerosis. In summary, notably greater levels of IgG4+ plasma cells are usual in NSHL, highlighting the requirement to eliminate Reed–Sternberg cells through morphology and immunohistochemistry in biopsies where IgG4-RD is speculated.