American Urological Association - Idiopathic Retroperitoneal Fibrosis (Ormond's Disease)
Idiopathic Retroperitoneal Fibrosis (Ormond's Disease)
- Ormond's disease is a diffuse or localized fibroblastic proliferation associated with chronic inflammation.
- Although benign, this lesion can be locally aggressive, with compression or obstruction of the ureters and vascular structures, including the aorta.
- Cause is unknown, but frequent association with immune disease and response to steroids suggests being immune-related (hyper-immunoglobulin G4 syndrome: elevated serum IgG4 and plasma cells are IgG4+).
- Gastrointestinal involvement is unusual, but may occur.
- Usually occurs in adults; rarely in children.
- Patients present with a history of pain in the lower abdomen, flank, or lower back.
- One third of cases associated with drugs (esp. methysergide, adrenergic blocking agents and methyldopa).
- May occur with malignancies (lymphoma, sarcoma or carcinoma), trauma or immune-mediated connective tissue disease.
- May be a part of multiple fibrosclerosis (systemic idiopathic fibrosis).
- Gross: ill-defined fibrous mass usually centered at the 4th and 5th lumbar vertebrae and often encasing one or both ureters (hydronephrosis) and/or vasculature as well (image A).
- Fibroblastic proliferation with densely hyalinized collagen.
- Variable (but generally obvious) chronic inflammatory infiltrate composed of lymphocytes and plasma cells (image B), (image C), & (image D).
- IgG4 positive plasma cells are present.
- Germinal center formation may occur with marked inflammation.