摘要
Rosai-Dorfman disease (RDD) is an infrequently encountered disorder characterized by histiocytes exhibiting emperipolesis and varying degrees of chronic inflammatory cell infiltrates. It is generally considered an important differential diagnosis of IgG4-related sclerosing disease because of their similar histopathologic features. We report herein a case of RDD in the parotid gland with an increase in the absolute number of IgG4 + plasma cells as well as an increase in the ratio of IgG4 + to IgG + plasma cells. We also discuss both disease entities and this overlapping phenomenon. ©2011 American Medical Association. All rights reserved.