A 67-year-old Caucasian female presented to Cleveland Clinic for evaluation of acute kidney injury secondary to bilateral ureteral obstruction that occurred two months prior to the current visit.
Over a period of six months, the patient had developed new-onset tiredness, difficulty working, and gastrointestinal complaints characterized by daily vomiting, intermittent generalized abdominal pain, and a six-pound weight loss.
An abdominal computed tomography (CT) scan demonstrated bilateral hydroureter extending to the upper pelvis (Figure 1a), where the ureters were obscured by a confluent soft tissue density anterior to the sacrum and extending inferiorly to the level of the lower pelvis (Figure 1b). Laboratory tests revealed a serum creatinine of 10.2 mg/dL and a BUN of 102 mg/dL. Her prior baseline creatinine level was 0.97 mg/dL. The patient underwent cystoscopy with bilateral ureteral stenting. Over the ensuing two months, serum creatinine gradually decreased to a new plateau of 2.72 mg/dL.
The patient was referred to the Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute at Cleveland Clinic for further evaluation. Her clinical examination was unremarkable. Laboratory testing demonstrated a serum creatinine of 2.7 mg/dL and a BUN of 50 mg/dL. IgG subclass 3 and 4 , CA 125, and beta 2 microglobulin levels were elevated.
After extensive discussion with the urology and kidney team, the patient underwent bilateral retrogrades, stent exchange, and bilateral robotic ureterolysis. The retrograde studies revealed that both kidneys were at a lower-than-normal anatomic position with significant medial deviated ureters, hydronephrosis, and hydroureter to the level of the ureteropelvic junction bilaterally.
The patient underwent extensive robotic ureter dissection on both the right and left side with multiple biopsies of the soft tissue mass. The left ureter was very adherent at the crossing of the iliac vessels requiring a psoas hitch with a ureteral implant on the left side. The patient tolerated the procedure well and was discharged on postoperative day 3.
The biopsy specimens demonstrated benign fibroadipose tissue with evidence of chronic inflammation. The IgG4 immunostain performed on the periureteral tissue showed more than 20 positive plasma cells per high power field.
The patient was treated with mycophenolate mofetil and prednisone. Inflammatory markers, CA 125, westergreen sedimentation rate, beta-2 microglobulin, and IgG sub-classes decreased on treatmentand serum creatinine value decreased to 1.4 mg/dL and BUN decreased to 42 mg/dL. A CT scan performed six months post-op demonstrated significant reduction in the size of the retroperitoneal and presacral soft tissue mass with almost complete resolution of the bilateral hydronephrosis.
IgG subclass 4-related autoimmune disease (IgG4-RSD) can involve multi-ple organ systems, which include retroperitoneum, bile ducts, pancreas, and salivary glands. The histopathology of the affected organs demonstrates extensive lymphoplasmacytic infiltration, abundant IgG subclass 4 positive plasma cells and fibrosis. Robotic ureterolysis is a valuable tool for ureteral dissection with less overall morbidity. Glucocorticoid therapy has been a treatment mainstay but combination therapy with prednisone and myocphenalate mofetil has proved effective more recently.
The authors are affiliated with the Cleveland Clinic’s Glickman Urological & Kidney Institute. Dr. Schreiber is Chair of the Department of Nephrology and Hypertension. Dr. Haber is an associate staff member in the Department of Urology.
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