2017 Volume 108 Issue 4 Pages 229-233
IgG4-related kidney disease (IgG4-RKD) is a comprehensive term for renal lesions associated with IgG4-related disease (IgG4-RD), which is a recently recognized clinical entity characterized by a dense lymphoplasmacytic infiltrate rich in IgG4+ plasma cells with fibrosis affecting several organs. A 70-year-old woman was referred to our hospital for an abnormality at the left renal hilum detected by CT scan. Urinalysis was negative, urine cytology was rated as Class IIIa, and contrast-enhanced CT revealed left renal pelvic wall thickening without an irregular lumen and swelling of bilateral obturator lymph nodes. Ureterorenoscopy and biopsy were performed, and results showed no evidence of malignancy. Then, laparoscopic pelvic lymphadenectomy was performed. Plasma cells were the predominant infiltrating inflammatory cells; immunostaining showed marked infiltration of IgG4+ plasma cells with >10 IgG4+ plasma cells per high-power field, and the IgG4+/IgG+ cell ratio was over 40%. Serum IgG4 was extremely high. We made a final diagnosis of possible IgG4-related disease according to Comprehensive diagnostic Criteria for IgG4-related disease 2011. We report a long-term (40-month) follow-up case of IgG4-related kidney disease without therapy because there are no symptoms.