Infrequent organ involvement in immunoglobulin G4-related prostate disease: A case report

BACKGROUND: Immunoglobulin G4-related prostate disease (IgG4-RPD) characterized by a high count of IgG4-positive plasma cells has distinctive serological and radiological findings. Here we report a case of a patient who was successfully treated for IgG4-RPD, which manifested as frequent micturition, dysuric, and systemic lymphadenopathy. CASE SUMMARY: The patient was a 33-year-old man who was referred to our hospital because of urinary tract symptoms that had persisted for 4 years. A physical examination revealed systemic lymphadenopathy and blood tests showed hyperglobulinemia with an IgG level of 18.90 g/L and an IgG4 level of 18.40 g/L. Computed tomography (CT) revealed bilateral lacrimal gland, right parotid gland and prostatic enlargement. Based on these findings, IgG4-RD was suspected, and further pathological examination and follow-up results showed expected results. Finally, the patient was diagnosed with IgG4-RPD based on clinical symptoms, pathological examination, therapeutic effects, and follow-up results. He received 50 mg oral prednisolone (the dose was gradually reduced and a low dose was used for long-term maintenance) in combination with cyclophosphamide 1.0 g via an intravenous drip for 6 mo. One year after the treatment was initiated, he was free of urinary or other complaints and his serum IgG4 level normalized. CONCLUSION: In IgG4-RPD with severe urinary tract symptoms, radiological findings should be carefully examined. IgG4-RPD prognosis is good because the disease responds well to glucocorticoids. Furthermore, it is urgent for clinicians and pathologists to improve their understanding of IgG4-RPD.