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IgG4-related systemic disease mimicking renal pelvic cancer: a rare case
Yiwei Wang, Xing Chen, Rongkui Luo
1Department of Urology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China. guo.jianming@zs-hospital.sh.cn.
Background:
Immunoglobulin G4-related disease (IgG4-RD) is a new clinical entity. Characteristic features of IgG4-RD are elevated serum IgG4 levels, infiltration of IgG4-positive cells, mass-forming lesions with fibrosis and good response to corticosteroids. The variable imaging features of IgG4-RD and the overlap with other differential diagnoses often pose a diagnostic challenge, as they frequently mimic malignant tumors or other inflammatory diseases in the abdomen.
Case Presentation:
A 54-year-old woman visited our hospital with left flank discomfort and palpebral edema. Computed tomography, magnetic resonance imaging, retrograde pyelography and positron emission tomography/computed tomography indicated renal pelvic cancer. However, after a left-sided nephroureteral cystectomy was performed, the mass was pathologically confirmed as an IgG4-related lesion. Her elevated serum IgG4 level and a past history of sicca complex supported the diagnosis of IgG4-RD.
Conclusions:
It is critical to recognize the importance of laboratory examinations such as serum IgG4 level if a patient has a past history of rheumatic disease.
