Retroperitoneal fibrosis, Ormond Disease
Retroperitoneal fibrosis (igG4 related disease) is idiopathic in 70% of cases and is thought to be a subset of idiopathic multifocal fibrosclerosis.
It is rare, affects men more than women (3:1) of all ethnicities, and
occurs at an average age of 40 to 60 years. Patients present (90%) with
pain in the lower back, abdomen, flank, and/or scrotum. Some patients
have systemic symptoms that include fever, anorexia, and malaise. The
physical examination is usually (75%) unremarkable, although
hypertension is common. Lower-extremity edema and phlebitis can be seen.
Laboratory findings are nonspecific, including elevated ESR/CRP (75% to
90% of cases) and azotemia (50%). Serologies
are typically negative. Radiographic CT findings show a homogeneous
mass surrounding the aorta that follows the iliac bifurcation.
Lymphadenopathy is rare. Medial deviation of the mid part of the ureter
are common (60% to 75%). Open, laparoscopic, or CT-guided biopsy shows
sclerosis and infiltration of mononuclear cells. Small-vessel vasculitis
is seen in 50% of cases. Biopsy helps to rule out secondary causes of
RPF (drugs, malignant disease, infections, IgG4-related systemic
disease). The etiology of IRPF is unknown but may be an exaggerated
local inflammatory reaction to oxidized low-density lipoprotein from
aortic atherosclerosis. An autoimmune process is also proposed because
RPF can occur in patients with other autoimmune diseases. Treatment
includes high-dose prednisone for 1 month with tapering off to 10 mg/day
by 3 to 6 months. Maintenance prednisone continues for 1 to 3 years.
Recurrence of the disease (10% to 30% of cases) or treatment resistance
is treated with mycophenolate mofetil, tamoxifen, or methotrexate.
Patients are monitored in terms of ESR/CRP, creatinine, and CT scans
every 3 months while on therapy and every 6 months when off treatment.