A 32 year old male with recently diagnosed hypertension was admitted for worsening abdominal pain and 20 lbs of unintentional weight loss over 4 months. He reported intermittent abdominal pain for a year associated with constipation, nausea, nonbloody nonbilous emesis, and low back pain radiating to the legs with weakness limiting ambulation. Associated symptoms included difficulty urinating, lightheadedness, and dyspnea on exertion. He recently immigrated from Haiti two weeks ago. Physical exam was significant only for tenderness in the periumbilical area. Labs were significant for elevated inflammatory markers and acute kidney injury. CT chest/abdomen/pelvis demonstrated homogeneous soft tissue encasing the left kidney/adrenal gland, renal vessels, juxtarenal aorta and IVC with mild bilateral hydronephrosis, bladder wall thickening, retrocrural lymphadenopathy and chronic splenic vein occlusion. The initial diagnosis was lymphoma. IR performed left pararenal soft tissue core biopsy and FNA, which demonstrated increased IgG and IgG4 plasma cells (IgG/IgG4 <50%) consistent with IgG4 related disease/retroperitoneal fibrosis. Serum IgG was diffusely elevated. Serological and infectious workup was negative. The patient was started on prednisone with significant improvement in his abdominal pain and urinary symptoms. Repeat CT in two months showed improving retroperitoneal fibrosis with persistent, but decreasing right hydronephrosis. He was switched to mycophenolate as a steroid sparing agent.
Discussion:
In our case, the encasement of the ureters explained the bilateral hydronephrosis and AKI on admission. Initially, this patient was suspected to have lymphoma; however, it is important to remember that both RF and lymphoma have similar presentations. CT imaging and histopathology can be utilized to differentiate: in RF, the fibrosis encases, but does not displace, the vessels as opposed to lymphoma, which does displace the vessels. As in this case, definitive diagnosis is made by biopsy demonstrating sclerosis and infiltration of mononuclear cells primarily IgG4 positive.
Conclusions:
Retroperitoneal fibrosis (RF), or Ormond’s Disease, is a rare condition of unclear etiology characterized by chronic non-specific inflammation of the retroperitoneum. Idiopathic RF, accounting for 70% of cases, is an IgG4 related disease characterized by inflammation and fibrosis surrounding intraabdominal organs. Secondary causes of RF are drugs, malignancy, infection, radiation, surgery, and environmental exposures: smoking. Early symptoms are non-specific such as lower back pain, weight loss, nausea, vomiting, and fevers. Most cases will present after urologic or renal involvement. Choice of imaging is CT scan to visualize extent of fibrosis. Medical treatment of idiopathic RF is glucocorticoids, which alleviated this patient’s symptoms. Mycophenolate or methotrexate are used if unresponsive to glucocorticoids. This case is an important reminder of the subtle presentation of this rare disease.