Abstract
In a 69-year-old woman with a history of Mikulicz’s disease, a hypoechoic solitary renal mass was identified on routine ultrasound examination. Based on the findings of computed tomography (CT) and magnetic resonance imaging (MRI), renal cell carcinoma was a possible diagnosis. Subsequent partial nephrectomy revealed a mass characterized by an increased number of blood vessels, internal hemorrhage, and a thick fibrous capsule. Immunohistochemically, the mass comprised of tubulointerstitial nephritis with increased immunoglobulin (Ig)G4-positive plasma cells and fibrosis. Generally, diagnosis of IgG4-related kidney disease (IgG4-RKD) is not difficult when the kidney is involved together with other systemic involvements. However, diagnosis becomes harder when a solitary renal mass appears as a single-organ involvement. On precise review of our imaging findings, MRI signals were markedly affected by hemorrhage, so the mass showed hypointensity on both T1- and T2-weighted imaging, and the signal of in-phase images decreased. Dynamic MRI showed no apparent enhancement of the mass, while CT showed an apparent enhancement effect. Capsule formation was another key finding for IgG4-RKD and was recognized as a gradually enhancing boundary zone surrounding the mass on both CT and MRI. When a solitary renal mass is associated with hemorrhage and thick capsule formation, inflammatory pseudotumor should be considered as differential diagnosis.
Similar content being viewed by others
References
Umehara H, Okazaki K, Masaki Y, et al. (2012) A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details. Mod Rheumatol 22:1-14
Takahashi N, Kawashiwa A, Fletcher JG, et al. (2007) Renal Involvement in Patients with Autoimmune Pancreatitis: CT and MR Imaging Findings. Radiology 242:791-801
Saeki T, Kawano M (2014) IgG4-related kidney disease. Kidney International 85(2):251-257
Kawano M, Saeki T, Nakashima H et al (2011) Proposal for diagnostic criteria for IgG4-related kidney disease. Clin Exp Nephrol 15:615-626
Szade A, Grochot-Przeczek A, Florczyk U et al (2015) Cellular and molecular mechanisms of inflammation-induced angiogenesis. IUBMB life 67(3):145-159
Walsh DA, Pearson CI (2001) Angiogenesis in the pathogenesis of inflammatory joint and lung diseases. Arthritis Res 3(3):147-153
Cai YI, Li HZ, Zhang YS (2016) IgG4-related inflammatory pseudotumor of the kidney mimicking renal cell carcinoma: A case report. Oncol Lett 11:3438–3440
Shoji S, Nakano M, Usui Y (2010) IgG4-related inflammatory pseudotumor of the kidney. Int J Urol 17:389-390
Wynn TA (2008) Cellular and molecular mechanisms of fibrosis. J Pathol 214(2):199-210
Funding
This study received no specific grant from any funding agency.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical approval
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.
Informed consent
Informed consent was obtained from the patient in the study.
Rights and permissions
About this article
Cite this article
Watanabe, H., Tanaka, H., Fujii, Y. et al. A case of immunoglobulin G4-related inflammatory pseudotumor mimicking renal cell carcinoma. Abdom Radiol 44, 1230–1236 (2019). https://doi.org/10.1007/s00261-018-01885-1
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00261-018-01885-1