IgG4-related Disease of the Ovary: A First Description.

IgG4-related disease has been previously described to involve numerous organs and anatomic sites, however, involvement of the ovary has not yet been reported in the literature. In this case report we describe an ovary involved with an inflammatory process with histopathologic features supportive of involvement by IgG4-related disease: a dense lymphoplasmacytic infiltrate with an eosinophilic component, obliterative phlebitis, and a prominent proportion of IgG-positive cells with IgG4 expression by immunohistochemistry (40%-50%). The differential diagnosis for this case would include eosinophilic perifolliculitis involving the ovary, another rare entity that shares the eosinophilic component of IgG4-related disease. In short, we present the first description of IgG4-related disease of the ovary providing morphologic characterization and immunohistochemical studies supporting the diagnosis.