Abstract: TH-PO078
A Case of IgG4-Related Kidney Disease with a Rare Renal Cyst
Session Information
- AKI: Liver Disease, Nephrotoxicity, Novel Therapeutics
November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Uchida, Hiroki, Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Yufu, Oita, Japan
- Okita, Jun, Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Yufu, Oita, Japan
- Kudo, Akiko, Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Yufu, Oita, Japan
- Nakata, Takeshi, Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Yufu, Oita, Japan
- Fukuda, Akihiro, Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Yufu, Oita, Japan
- Uesugi, Noriko, Department of Pathology, Fukuoka University School of Medicine, Fukuoka, Fukuoka, Japan
- Shibata, Hirotaka, Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Yufu, Oita, Japan
Introduction
IgG4-related kidney disease (IgG4-RKD) is characterized by tubulointerstitial nephritis with elevated IgG4-positive plasma cells. Characteristic imaging findings of IgG4-RKD include diffuse kidney enlargement, multiple low-density lesions, solitary masses, and diffuse thickening of the renal pelvis wall. Here, we report a case of IgG4-RKD with a rare renal cystic formation that shrank after steroid treatment.
Case Description
A 73-year-old man was admitted to our hospital with acute kidney injury and tubulointerstitial disorder. Blood tests showed elevated IgG and IgG4 (IgG 3941 mg/dL，IgG4 425 mg/dL). CT imaging showed enlargement of both kidneys, and a solitary mass in the left kidney. Renal biopsy of the right kidney showed tubulointerstitial nephritis with storiform fibrosis and increased IgG4-positive plasma cells, which led to a diagnosis of IgG4-RKD. Ultrasonography showed no substantial component or blood flow within the kidney mass, and MRI showed diffusion-weighted images with heterogeneous diffusion restriction inside the kidney mass, and no clinical findings to suggest infection, suggesting a simple cystic lesion. Steroid treatment for IgG4-RKD improved kidney function and IgG4 levels, in addition, CT imaging showed a markedly reduction of cystic renal mass (Fig 1).
Discussion
In one case, a benign renal lesion due to IgG4-RKD was found after nephrectomy, while in another case, a renal mass thought to be a benign renal lesion was found to be renal cancer after steroid treatment. In this case, the mass lesion shrank following steroid treatment, and CT and MRI imaging findings suggested a cystic renal mass caused by IgG4-RKD. Careful judgment is required when deciding if renal masses may be benign or malignant in patients with IgG4-RKD. Here, we report a rare case of a solitary renal cystic mass associated with IgG4-RKD.