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.

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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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