Isolated testicular immunoglobulin G4-related disease: A mimicker of malignancy

ImmunoglobulinG4 related disease (IgG4RD) is a systemic fibroinflammatory disease recognized recently. This usually presents with multiorgan involvement. We are reporting a case of a35-year-old male patient with isolated IgG4RD of the testis. This patient presented with right testis pain which responded to conservative treatment. However, later, he reported with hard swelling in the right testis which on imaging was suggestive of malignancy and hence underwent radical orchiectomy. Histopathology with immunohistochemical staining confirmed IgG4RD of the testis. To the best of our knowledge, this is the first report of purely isolated case of IgG4RD of testis in English literature.