Idiopathic retroperitoneal fibrosis: Clinicopathologic features and differential diagnosis

Abstract

Idiopathic retroperitoneal fibrosis (IRF) is a rare disease often causing obstructive uropathy. We evaluated the clinicopathologic features of 24 patients with IRF to characterize the histopathology of the disease and to provide a framework for the differential diagnosis with other retroperitoneal fibrosing conditions. Retroperitoneal specimens were analyzed by light and electron microscopy and by immunohistochemistry. Most patients presented with abdominal/lumbar pain, constitutional symptoms, and high acute-phase reactants. Overall, 20 had ureteral involvement and 13 developed acute renal failure. The retroperitoneal tissue consisted of a fibrous component and a chronic inflammatory infiltrate with the former characterized by myofibroblasts within a type-I collagen matrix. The infiltrate displayed perivascular and diffuse patterns containing lymphocytes, macrophages, plasma cells, and eosinophils. The perivascular aggregates had a central core of CD20(+) cells and a mantle of CD3(+) cells in equal proportions. In the areas of diffuse infiltrate, CD3(+) cells outnumbered the CD20(+) cells. Most plasma cells were positive for the IgG4 isotype. Small vessel vasculitis was found in the specimens of 11 patients. Our study indicates that a sclerotic background with myofibroblasts associated with a diffuse and perivascular infiltrate mainly consisting of T and B lymphocytes may be a pathological hallmark of IRF.

Clinical Features of 10 Patients with IgG4-related Retroperitoneal Fibrosis

“…The male-to-female ratio was 1:0.6 in our series, which is similar to that previously reported (1:0.3-1:0.8 (11)(12)(13)(14)). In one review of 14 cases of IgG4-related RF (23), all patients were men and their mean age was 67 years.…”

“…The mean age at diagnosis of IgG4-related RF was 70.1 years in our series, whereas previous studies have reported a younger mean age at diagnosis, ranging from 54.2 to 64 years (11)(12)(13)(14). The male-to-female ratio was 1:0.6 in our series, which is similar to that previously reported (1:0.3-1:0.8 (11)(12)(13)(14)).…”

“…Abdominal and/or back pain is reportedly the most common symptom, affecting 88-94% of RF patients (11)(12)(13)(14). However, in the present series, symptoms predominantly related to RF (back pain and edema of the lower extremities) were observed in only two patients, and the remaining eight patients reported initial symptoms due to associated diseases.…”

“…RF occasionally occurs as an extrapancreatic lesion of AIP, and some forms of RF can be classified as IgG4-related disease (9,10). However, most papers published on the topic of RF do not include the concept of IgG4-related RF (11)(12)(13)(14). Although the literature contains several case reports of IgG4-related RF (15)(16)(17)(18), only one such case series has been published (19).…”

Renal allotransplantation in retroperitoneal fibrosis: technical aspects

“…There Picture story are idiopathic (as in our patient) and secondary forms. Renal failure due ureteric obstruction is common [3]. Only very few reports of kidney transplantation in such patients.…”