Rare case of immunoglobulin G4‐related disease arising in gonadal glands with long‐term remission without steroid treatment: Discussion and literature review

Introduction Immunoglobulin G4-related disease embraces a wide range of extra-pancreatic manifestations. However, localized pathogenesis in gonadal glands, including testes or seminal vesicles, is rare. The clinical course and therapeutic strategy for this disease have not been clearly characterized. Case presentation A 61-year-old Asian male had a left orchiectomy and right seminal vesicle biopsy because of a mass in the left testis and right seminal vesicle. Histological findings showed an infiltration of immunoglobulin G4-positive plasma cells in the respective tissues and met immunoglobulin G4-related disease diagnostic criteria. No recurrence and exacerbation have been observed after 12 years' follow-up without any clinical intervention. To date, immunoglobulin G4-related disease in gonadal tissue is rare. This is the first case with mass-forming lesions in both the testis and seminal vesicle. Conclusion Based on the clinical course of our case and the literature, for patients with accurately diagnosed inactive gonadal immunoglobulin G4-related disease, watchful waiting is a feasible clinical treatment option.