Kimura’s disease of the lacrimal gland mimicking IgG4-related orbital disease

Background Kimura’s disease (KD) is a rare and benign chronic inflammatory soft tissue disorder of unknown origin, which predominantly inflicts young male adults in Asia. IgG4-related disease is a new disease concept, established this century and characterized by fibrosis and sclerosis of the involved organs, with infiltration of IgG4-positive plasma cells. These two kinds of diseases share similar characteristics, which may complicate their diagnosis.