Two cases of immunoglobulin G4‐related disease diagnosed by transvaginal urethral needle biopsy

INTRODUCTION: Immunoglobulin G4‐related disease is a systemic disease characterized by multifocal systemic involvement. We report two cases of women diagnosed with immunoglobulin G4‐related disease in the urethra. CASE PRESENTATION: Case 1: A 67‐year‐old woman presented with discomfort around her perineum. Magnetic resonance imaging revealed a well‐defined mass around the urethra. She underwent an ultrasound‐guided core needle biopsy of the mass. The pathologic specimen showed immunoglobulin G4 positive cells. Steroid therapy was initiated, causing improvement of symptoms, decreased serum immunoglobulin G4 levels, and shrinking of the mass. Case 2: An 89‐year‐old woman was accidentally diagnosed with renal pelvic wall thickening on computed tomography. The pathologic specimen captured by ultrasound‐guided needle biopsy showed immunoglobulin G4 positive cells. She had no symptoms and received no medical treatment. CONCLUSION: The frequency of urethral mass formation in female patients with immunoglobulin G4‐related disease may also be high, and an echo‐guided transvaginal urethral biopsy may be performed as a definitive diagnostic tool for immunoglobulin G4‐related disease.