DOI:10.2214/AJR.07.3629
AJR 2008; 191:423-431
© American Roentgen Ray Society
Retroperitoneal Fibrosis: A Review of Clinical Features and Imaging Findings
Carmel G. Cronin1,
Derek G. Lohan1,
Michael A. Blake2,
Clare Roche1,
Peter McCarthy1 and
Joseph M. Murphy1
1 Department of Radiology, University College Hospital, Newcastle Rd., Galway,
Ireland.
2 Department of Radiology, Massachusetts General Hospital, Boston, MA.
Received January 5, 2008;
accepted after revision February 8, 2008.
CME
This article is available for CME credit. See
www.arrs.org
for more information.
Address correspondence to C. G. Cronin
(carmelcronin2000{at}hotmail.com).
Abstract
OBJECTIVE. Retroperitoneal fibrosis is a rare collagen vascular
disorder of unclear cause. Both benign and malignant associations have been
described, rendering differentiation of these entities of paramount importance
because sinister pathology alters the diagnosis. Thus, a high level of
diligence is required in the investigation of this condition, particularly in
patients with concomitant systemic conditions.
CONCLUSION. Familiarity with the realm of imaging manifestations of
retroperitoneal fibrosis is vital to ensure correct diagnosis and optimal
treatment.
Keywords: fibrosis • malignant retroperitoneal disease • retroperitoneal fibrosis
Introduction
Retroperitoneal fibrosis is an uncommon fibrotic reaction that is thought
to have been first described by the French urologist Albarran in 1905 as
ureteral obstruction secondary to fibrotic changes in the retroperitoneal
space
[1–3].
The description of two cases by Ormond
[4] in 1948 established
retroperitoneal fibrosis as a clinical entity. This condition has previously
been described as chronic periaortitis
[2], periureteritis
[5], and sclerosing
retroperitoneal granuloma [6].
Because ureteral obstruction is a common sequela of retroperitoneal fibrosis,
excretory urography or retrograde pyelography may be used to outline the site
and severity of obstruction
[7–10].
Today, improvements in cross-sectional imaging have obviated these techniques
in many instances. CT
[11–16]
and MRI
[17–20]
have become the mainstays of diagnosis and allow comprehensive evaluation of
the extent and sequelae of this condition. The role of nuclear scintigraphy,
most notably in the form of 18F-FDG PET, has also been recently
assessed
[21–23].
Malignant retroperitoneal fibrosis is estimated to occur in up to 8% of cases
[24]. Because the prognosis of
malignant retroperitoneal fibrosis is poor
[17], an awareness of its
potential presence and sufficient knowledge of the typical and atypical
radiologic features are central to the evaluation of affected patients.
Epidemiology
Retroperitoneal fibrosis has an incidence of one per 200,000
[1,
25]. It is typically seen in
people 40–60 years old
[24,
26,
27], and men are two to three
times more likely to develop retroperitoneal fibrosis than women. There is no
ethnic predilection. Most (> 70%) cases are thought to be idiopathic
[28]; the remainder occur in
association with inflammatory disorders, malignancies, or medications. Rare
pediatric [29,
30] and familial
[28] reports have been
described.
Although usually regarded as an obstructive uropathy, retroperitoneal
fibrosis has been increasingly recognized as a systemic condition. Its
manifestations are diverse, including mediastinitis, thyroiditis, and
sclerosing cholangitis (Appendix
1). Indeed, associations with various immunologic disorders and
favorable responses to immunosuppressive agents have prompted proposals of an
autoimmune cause for retroperitoneal fibrosis. One such postulation is that
retroperitoneal fibrosis is an exaggerated inflammatory response to advanced
atherosclerosis, the suspected allergen being a component of ceroid, which is
produced in the atheroma
[31].
Clinical Presentation
Early symptoms tend to be relatively nonspecific, most commonly abdominal
or lumbar discomfort (Appendix
2). As the degree of fibrosis progresses, the compressive effects
of the abnormal soft-tissue mass determine symptomatic evolution. Severe pain
in the lower back, abdomen, and flank areas and unilateral or bilateral lower
extremity swelling are most common. A decrease in urinary excretion may herald
renal or ureteral involvement. Testicular swelling in men and endometriosis in
women may occur secondary to anatomic distortion
[1,
2,
7,
32]. The diagnosis of
retroperitoneal fibrosis is often delayed, either because of its manifestation
in the absence of clinical symptoms or because of its occurrence in the
presence of associated concomitant disease. Potentially confounding
differential diagnoses are presented in
Appendix 3.
Pathology
On gross examination, retroperitoneal fibrosis manifests as a pale,
plaquelike mass with ill-defined margins and enveloping adjacent viscera,
including the ureters and the inferior vena cava. Microscopic evaluation
confirms the presence of fibroblastic proliferation with a pleomorphic
inflammatory cell infiltrate consisting predominantly of lymphocytes,
macrophages, and vascular endothelial cells, many of which are positive for
human leukocyte antigen, DR subregion (HLA-DR)
[31]. Comprehensive evaluation
of the entire specimen is vital for exclusion of an underlying neoplastic
process.
Imaging Features
Conventional Radiography
This technique is of limited diagnostic value and is often performed before
retroperitoneal fibrosis is considered in the differential diagnosis.
Abdominal radiographs are most often unremarkable, although in the late stages
they may show a central soft-tissue mass or silhouetting of the psoas shadow.
Features related to rare complications of retroperitoneal fibrosis, including
bowel dilatation secondary to obstruction or pneumatosis relating to
infarction, may be appreciated. Osseous associations of retroperitoneal
fibrosis include ankylosing spondylitis, Pott's disease (tuberculosis) of the
spine, and metastatic disease, all of which may be seen on conventional
radiography. Chest radiographs may show signs of noncardiogenic pulmonary
edema (increased airspace density, pleural effusions, and upper lobe venous
diversion in the absence of cardiomegaly) secondary to nephrogenic fluid
overload. Pulmonary fibrosis secondary to disorders such as systemic lupus
erythematosus and ankylosing spondylitis may suggest the diagnosis.
Mediastinal widening may indicate the presence of mediastinal fibrosis.
Excretory Urography
Excretory urography predates cross-sectional imaging as the technique of
choice in the evaluation of patients with retroperitoneal fibrosis. Diagnosis
relied on the presence of a classic triad consisting of delayed renal contrast
excretion with unilateral (20% of cases) or bilateral (68% of cases)
hydronephrosis and proximal hydroureter secondary to ureteral involvement,
medial deviation of the middle third of both ureters, and tapering of the
ureteral lumen at the L4–L5 vetebral level
[7–9].
However, the sensitivity and specificity of this approach were limited because
medial deviation of the ureter, considered a classic sign of retroperitoneal
fibrosis on pyelography, may be seen in 20% of unaffected individuals
[33]. Furthermore,
hydronephrosis and hydroureter may be seen to varying degrees in the presence
of retroperitoneal fibrosis according to the stage and severity of the disease
process. Uncertainty exists regarding the process involved in the production
of hydronephrosis and hydroureter; Lalli
[10] suggested that
interference with ureteral peristaltic activity rather than mechanical
obstruction was at fault. This theory is further supported by the relative
ease with which ureteral catheters may traverse areas of narrowing in the
presence of retroperitoneal fibrosis
[10,
34].
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Fig. 1A —60-year-old man with biopsy-proven idiopathic retroperitoneal
fibrosis. Transverse sonogram at level of mid aorta reveals presence of
paraaortic and preaortic hypoechoic soft-tissue mass (arrows). Right
ureteral and pelvicalyceal dilatation were found to coexist.
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Fig. 1B —60-year-old man with biopsy-proven idiopathic retroperitoneal
fibrosis. Correlating CT image also shows obstructive uropathy
(arrowheads) resulting from ureteral involvement that precluded
contrast administration. Note that calcified abdominal aorta is not elevated
from underlying lumbar spine and relatively smooth peripheral margins of
abnormal soft tissue (arrows).
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Fig. 2A —55-year-old man with retroperitoneal fibrosis. Axial oral and
IV contrast-enhanced CT images show presence of low-attenuation mass anterior
and lateral to aorta and iliac vessels, without anterior displacement of
either aorta or inferior vena cava. Retroperitoneal mass obliterates fat plane
between vessels and psoas muscle (arrows, A). Plaque
bifurcates and follows common iliac arteries (arrowhead,
B).
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Fig. 2B —55-year-old man with retroperitoneal fibrosis. Axial oral and
IV contrast-enhanced CT images show presence of low-attenuation mass anterior
and lateral to aorta and iliac vessels, without anterior displacement of
either aorta or inferior vena cava. Retroperitoneal mass obliterates fat plane
between vessels and psoas muscle (arrows, A). Plaque
bifurcates and follows common iliac arteries (arrowhead,
B).
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Sonography
Retroperitoneal fibrosis may be identified as a hypoechoic or anechoic,
well-demarcated although irregularly contoured retroperitoneal mass on
sonography [35] (Figs.
1A and
1B). Varying degrees of
hydronephrosis and hydroureter may result. A comprehensive evaluation of the
prevertebral and paravertebral lumbar spine is essential to fully assess the
presence and extent of the fibrotic reaction.
A number of sonographic characteristics have been suggested as having
potential value in determining the underlying cause of retroperitoneal
fibrosis. Caudal extension beyond the sacral promontory and the absence of
lobulation suggest a benign cause; however, these signs are of insufficient
specificity to allow the exclusion of malignancy. Doppler flow evaluation has
also been assessed in the differentiation of benign from malignant
retroperitoneal fibrosis, with limited success
[36]. Indeed, the overall
sensitivity of sonography in the detection of retroperitoneal fibrosis is
poor; only 25% of affected patients in whom disease is identified on CT yield
a corresponding abnormality on sonography
[11,
30]. However, abdominal
sonography may be of value in the detection of coexisting primary biliary
cirrhosis, bile duct dilatation due to common bile duct stricturing, portal
hypertension due to portal vein compression, and focal or diffuse pancreatic
distortion due to sclerosing pancreatitis.
CT
The widespread availability of MDCT has allowed comprehensive evaluation of
retroperitoneal fibrosis location, extent, and effect on adjacent organs and
vascular structures. CT may also allude to the underlying cause, such as
abdominal aortic aneurysm or inflammation relating to pancreatitis or
mesenteric lymphadenopathy. Retroperitoneal fibrosis most often manifests as a
paraspinal, well-demarcated but irregular retroperitoneal mass that is
isodense to surrounding muscle
[1] (Figs.
1A,
1B,
2A,
2B,
3A, and
3B). Initial fibrosis tends to
begin near the aorta and the iliac arteries, extending through the
retroperitoneum to involve the ureters. The center of fibrosis is usually
located at the level of the aortic bifurcation; this abnormal tissue
bifurcates to follow the common iliac arteries. Significant extension may
occur, anteriorly to involve the duodenum, pancreas, and spleen, and
craniocaudally to extend from the mediastinum to the sacrum. Retroperitoneal
fibrosis per se is not known to produce local bone destruction, although such
osseous involvement may occur secondary to underlying malignancy. As a rule,
the abdominal aorta and inferior vena cava are not displaced anteriorly from
the spine as a result of retroperitoneal fibrosis, but exceptions may occur
[13].
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Fig. 3A —55-year-old man with inflammatory abdominal aortic aneurysm.
Oral and IV contrast-enhanced axial (A) and coronal (B) CT
images show ill-defined mass of soft-tissue attenuation surrounding
atheromatous aneurysm. Bilateral nephrostomy tubes have been placed for
obstructive uropathy.
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Fig. 3B —55-year-old man with inflammatory abdominal aortic aneurysm.
Oral and IV contrast-enhanced axial (A) and coronal (B) CT
images show ill-defined mass of soft-tissue attenuation surrounding
atheromatous aneurysm. Bilateral nephrostomy tubes have been placed for
obstructive uropathy.
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The degree of soft-tissue enhancement on CT correlates with activity of the
fibrotic process. Avid enhancement may be seen in the acute stages, with
increases of 20–60 H after contrast administration. Little or no
enhancement may be seen in the presence of advanced or chronic disease
[11]. Unfortunately, many
patients may have renal impairment secondary to obstructive uropathy, which
precludes the administration of IV contrast agents. In such cases, biochemical
markers of inflammation, including erythrocyte sedimentation rate and
C-reactive protein level, may be of benefit in monitoring the response to
therapy.
However, the fibrous reaction may not be readily appreciable on CT. Indeed,
Brun et al. [12] reported that
one third of patients with surgically proven retroperitoneal fibrosis had no
corresponding abnormality on CT.
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Fig. 4A —50-year-old man with biopsy-confirmed non-Hodgkin's lymphoma.
Contrast-enhanced CT scans show bulky soft-tissue mass (arrow,A) surrounding aorta and inferior vena cava. Note slight elevation
of aorta from spine, feature suggestive of neoplasia.
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Fig. 4B —50-year-old man with biopsy-confirmed non-Hodgkin's lymphoma.
Contrast-enhanced CT scans show bulky soft-tissue mass (arrow,A) surrounding aorta and inferior vena cava. Note slight elevation
of aorta from spine, feature suggestive of neoplasia.
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Fig. 5 —64-year-old woman with abdominal pain. Contrast-enhanced
abdominal CT scan reveals presence of retroperitoneal mass. Aorta is minimally
elevated from underlying spine, raising concern for underlying neoplasia.
CT-guided biopsy and subsequent cystoscopy confirmed presence of metastatic
transitional cell carcinoma of urinary bladder.
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Fig. 6 —35-year-old man with HIV who presented with abdominal pain
and fever. Sputum culture and chest radiography suggested tuberculosis. IV
contrast-enhanced CT scan of abdomen shows nonlobulated retroperitoneal
paraaortic mass of soft-tissue attenuation. Biopsy confirmed benign infective
lymphadenopathy.
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CT in the Differentiation of Benign Retroperitoneal Fibrosis from Neoplasia
Despite the attention of a number of investigators, attempts to define CT
characteristics that may allow confident differentiation of benign from
malignant retroperitoneal fibrosis have proven futile. However, several
features have been described that may aid in the suggestion of the presence of
underlying neoplasia. Malignant retroperitoneal fibrosis has a tendency to be
larger and bulkier, displaying mass effect and displacing the aorta and
inferior vena cava anteriorly from the spine and the ureters laterally
[13] (Figs.
4A,
4B, and
5). The occurrence of this
vascular displacement is likely related to enlargement of the lymph nodes
lying posterior to the aorta and inferior vena cava. In contrast, the purely
fibrotic process involved in idiopathic retroperitoneal fibrosis results in
"tethering" of these structures to the underlying vertebrae (Figs.
1A,
1B,
2A,
2B,
3A, and
3B). However, the sensitivity
and specificity of these features are poor and exceptions are encountered
(Figs. 6,
7, and
8).
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Fig. 7 —35-year-old woman with endometrial adenocarcinoma. Confluent
low-attenuation retroperitoneal metastatic deposits (arrow) have
appearance similar to that of retroperitoneal fibrosis. CT scan shows this
soft tissue is centered on lower infrarenal aorta, has relatively smooth
margins, and does not elevate aorta from spine—features that may allow
differentiation of malignant from benign retroperitoneal fibrosis. Note
associated left hydronephrosis (arrowhead).
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Fig. 8 —Contrast-enhanced CT scan in 47 year-old-man shows
retroperitoneal mass that fails to elevate aorta from spine. However, this
mass has suspicious lobulated anterior margin. Upper gastrointestinal
endoscopy (not shown) revealed presence of gastric adenocarcinoma, with
subsequent biopsy-proven retroperitoneal metastasis.
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Fig. 9 —50-year-old woman with new diagnosis of pancreatic
adenocarcinoma. CT scan shows paraaortic retroperitoneal soft-tissue mass but
no elevation of aorta from spine, which suggests benign cause. However, this
mass has lobulated anterior margin, which raises concern for metastatic
disease. Subsequent biopsy confirmed malignant nature of this paraaortic soft
tissue.
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Brun et al. [12] proposed
using soft-tissue distribution as a distinguishing feature between benign and
malignant retroperitoneal fibrosis. Those authors noted a tendency for
lymphoma to have a more cephalad distribution, whereas retroperitoneal
fibrosis predominantly occurs caudal to the renal hilum. Although this may
certainly be the case, exceptions occur, so this approach has limited clinical
utility.
The morphologic characteristics of the soft-tissue mass have also been
suggested as possibly allowing differentiation of benign from malignant
retroperitoneal fibrosis. Idiopathic retroperitoneal fibrosis has a tendency
to manifest as a plaquelike density with peripheral infiltration, whereas the
presence of neoplasia results in peripheral nodularity and lobulation
(Fig. 9). Again, although it
is of potential value in suggesting an underlying cause, this approach has
failed to hold true in many cases
[37].
Others have suggested a relationship between soft-tissue contrast
enhancement and underlying cause, but with little success
[14–16].
Retroperitoneal fibrosis is known to enhance to different extents depending on
degree of inflammation, with chronic plaques showing little if any
enhancement. Furthermore, metastatic deposits may also show enhancement,
depending on the vascularity of the underlying primary neoplasm.
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Fig. 10A —59-year-old man with biopsy-confirmed metastatic
retroperitoneal fibrosis of unknown primary cause. Coronal (A and
B) and axial (C and D) T1-weighted and steady-state free
precession T2-weighted MR images show low-signal-intensity paraaortic mass
(arrow,A–C) with slightly nodular outline, raising
suspicion for presence of malignancy. Note bilateral ureteral dilatation
(arrows, D).
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Fig. 10B —59-year-old man with biopsy-confirmed metastatic
retroperitoneal fibrosis of unknown primary cause. Coronal (A and
B) and axial (C and D) T1-weighted and steady-state free
precession T2-weighted MR images show low-signal-intensity paraaortic mass
(arrow, A–C) with slightly nodular outline, raising
suspicion for presence of malignancy. Note bilateral ureteral dilatation
(arrows, D).
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Fig. 10C —59-year-old man with biopsy-confirmed metastatic
retroperitoneal fibrosis of unknown primary cause. Coronal (A and
B) and axial (C and D) T1-weighted and steady-state free
precession T2-weighted MR images show low-signal-intensity paraaortic mass
(arrow, A–C) with slightly nodular outline, raising
suspicion for presence of malignancy. Note bilateral ureteral dilatation
(arrows, D).
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Fig. 10D —59-year-old man with biopsy-confirmed metastatic
retroperitoneal fibrosis of unknown primary cause. Coronal (A and
B) and axial (C and D) T1-weighted and steady-state free
precession T2-weighted MR images show low-signal-intensity paraaortic mass
(arrow, A–C) with slightly nodular outline, raising
suspicion for presence of malignancy. Note bilateral ureteral dilatation
(arrows, D).
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Fig. 11A —50-year-old man with retroperitoneal fibrosis. Inflammatory
abdominal aneurysm and inflammatory retroperitoneal fibrosis are seen on
fat-saturated axial T1 gradient-recalled echo image (A). MR images show
near-circumferential paraaortic soft-tissue mass without elevation of aorta
from underlying spine. Right hydronephrosis and right renal atrophy have
resulted. Contrast-enhanced image (B) shows intense enhancement of
retroperitoneal fibrosis, consistent with active inflammation.
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Fig. 11B —50-year-old man with retroperitoneal fibrosis. Inflammatory
abdominal aneurysm and inflammatory retroperitoneal fibrosis are seen on
fat-saturated axial T1 gradient-recalled echo image (A). MR images show
near-circumferential paraaortic soft-tissue mass without elevation of aorta
from underlying spine. Right hydronephrosis and right renal atrophy have
resulted. Contrast-enhanced image (B) shows intense enhancement of
retroperitoneal fibrosis, consistent with active inflammation.
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Fig. 12B —60-year-old man with idiopathic retroperitoneal fibrosis.
Arrows indicate retroperitoneal soft-tissue mass. Axial unenhanced T1-weighted
gradient-recalled echo (B) and contrast-enhanced fat-saturated
T1-weighted gradient-recalled echo (C) acquisitions show little
soft-tissue enhancement after contrast administration, which also indicates
absence of associated inflammation.
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Fig. 12C —60-year-old man with idiopathic retroperitoneal fibrosis.
Arrows indicate retroperitoneal soft-tissue mass. Axial unenhanced T1-weighted
gradient-recalled echo (B) and contrast-enhanced fat-saturated
T1-weighted gradient-recalled echo (C) acquisitions show little
soft-tissue enhancement after contrast administration, which also indicates
absence of associated inflammation.
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MRI
As is the case with CT, MRI allows comprehensive large-field-of-view
evaluation of the retroperitoneal structures, including revealing valuable
information that may indicate the cause of retroperitoneal fibrosis or its
associated complications. MRI does so with soft-tissue contrast resolution far
superior to that of CT, while precluding the need for the administration of
iodinated contrast medium.
Retroperitoneal fibrosis has signal characteristics similar to those of
other fibrotic processes, with a tendency toward diffusely low signal
intensity on T1-weighted imaging (Figs.
10A,
10B,
10C, and
10D). The T2 signal of this
tissue may vary considerably, however, which is a reflection of the degree of
associated active inflammation (and thus edema). Soft-tissue contrast
enhancement can be expected to mirror the degree of edema identified on
T2-weighted imaging (Figs.
11A,
11B,
12A,
12B, and
12C). Chronic, inactive
fibrosis will have little such edema and thus be visualized as having low
signal on both T1- and T2-weighted imaging
[18,
19]. This feature may prove
valuable in assessing a patient's response to treatment; decreasing edema, and
thus T2-signal, indicates a favorable therapeutic response. Accompanying
decreases in gadolinium contrast enhancement should also be expected on
implementation of appropriate therapy
[19,
20] (Figs.
11A,
11B,
12A,
12B, and
12C).
The manifestation of malignant retroperitoneal fibrosis on MRI may be
variable and is often difficult to differentiate from benign causes of this
entity [17]. Signal intensity,
the presence or absence of soft-tissue edema, and the degree of contrast
enhancement may be quite nonspecific, rendering tissue characterization by MRI
inaccurate in many cases [17].
Presence or absence of aortic elevation from the underlying spine,
distribution of the soft-tissue mass, morphologic features such as marginal
lobulation, and degree of contrast enhancement have proven equally as futile
for MRI as for CT in the confident differentiation of benign from malignant
causes of retroperitoneal fibrosis (Figs.
10A,
10B,
10C, and
10D).
Scintigraphy
The degree of 67Ga uptake in retroperitoneal fibrosis may be
expected to mirror its inflammatory activity, with avid concentration of this
agent in its early, inflammatory stages and little, if any uptake in the late,
fibrotic stage [38,
39]. Similarly for FDG PET,
metabolically active retroperitoneal fibrosis will show increased radiotracer
uptake, irrespective of a benign or malignant underlying cause. Nonetheless,
FDG PET has been successfully applied in the evaluation of disease activity
[21]. FDG PET also facilitates
the detection of remote disease such as seen in multifocal fibrosclerosis,
occult neoplasm, or infectious processes with which retroperitoneal fibrosis
may be secondarily associated
[22,
35].
In many instances, despite implementation of effective medical treatment
for retroperitoneal fibrosis, residual retroperitoneal tissue persists. Vaglio
et al. [23] reported the
usefulness of FDG PET in confirming the absence of disease activity in
patients with decreased concentrations of acute phase reactants, evidenced by
attenuated or absent FDG accumulation (Figs.
13A,
13B,
13C, and
13D). This technique may also
prove valuable in the follow-up of these patients because increasing
radiotracer uptake heralds inflammatory relapse.
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Fig. 13A —52-year-old man with biopsy-proven idiopathic retroperitoneal
fibrosis. Coronal fused PET/CT (A) and coronal PET (B) images
show increased paraaortic uptake of 18F-FDG, consistent with active
inflammation of retroperitoneal fibrosis (white arrows). Mild
right-sided ureteral obstruction is also shown on PET image (B)
(black arrow, B).
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Fig. 13B —52-year-old man with biopsy-proven idiopathic retroperitoneal
fibrosis. Coronal fused PET/CT (A) and coronal PET (B) images
show increased paraaortic uptake of 18F-FDG, consistent with active
inflammation of retroperitoneal fibrosis (white arrows). Mild
right-sided ureteral obstruction is also shown on PET image (B)
(black arrow, B).
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Fig. 13C —52-year-old man with biopsy-proven idiopathic retroperitoneal
fibrosis. Follow-up PET/CT (C) and coronal PET (D) images 2
months after immunotherapy show residual paraaortic tissue (arrows,C) but no radiotracer uptake, thus indicating favorable response
to treatment.
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Fig. 13D —52-year-old man with biopsy-proven idiopathic retroperitoneal
fibrosis. Follow-up PET/CT (C) and coronal PET (D) images 2
months after immunotherapy show residual paraaortic tissue (arrows,C) but no radiotracer uptake, thus indicating favorable response
to treatment.
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Management Options
As we have seen, current imaging techniques are insufficiently specific to
allow confident differentiation between idiopathic retroperitoneal fibrosis
and secondary retroperitoneal fibrosis due to malignancy, infection, or other
causes. As a result, open or imaging-guided biopsy remains the mainstay of
diagnostic confirmation [7,
13,
22,
40]. The choice of biopsy
technique depends on many factors: for example, the size and anatomic location
of the mass, CT or MRI evidence of active inflammation, the overall estimated
risk of malignancy, the operator's level of experience, and patient
suitability and preference. Multiple biopsy techniques have been used in
sampling retroperitoneal fibrosis, including open biopsy, laparoscopic biopsy,
transcaval retroperitoneal biopsy
[41], and fine-needle
aspiration [42]. However, in
malignant retroperitoneal fibrosis, the metastatic cells are usually dispersed
so diffusely in the fibrotic plaque that multiple deep surgical biopsies are
necessary to establish the diagnosis
[13,
43]. CT-guided fine-needle
aspiration or core biopsies, because of the small amount of tissue sampled,
are considered far less effective and less reliable than deep surgical
biopsies [44]. A diagnostic
and management dilemma may arise because even when negative needle biopsies
are obtained, a diagnosis of benign disease may be erroneously made because of
the paucity of malignant cells in their surrounding desmoplastic reaction
[43]. However, Koep and
Zuidema [7] found that if no
malignancy is present on biopsy material, the patient can be given a fairly
optimistic prognosis with a cumulative mortality rate of 9%. Those authors
suggested that when suboptimal improvement occurs, surgical reexploration may
be indicated and further search for malignancy should be undertaken
[7].
Effective management depends on removal of the offending cause, when
identified. Corticosteroids achieve prompt improvement of symptoms and often
lead to a reduction in size of the retroperitoneal mass and resolution of
obstructive complications [21,
45]. Supplementation with
other immunotherapeutic agents, or even surgical intervention, may also be
required, depending on patient response and subsequent imaging findings.
Disease-modifying antirheumatic drugs (DMARDs) and immunosuppressive drugs may
be of value, either as steroid-sparing agents or in cases refractory to
steroids. A number of benign fibrotic tumors (e.g., desmoid tumors) have shown
response to tamoxifen. This selective estrogen receptor modulator has been
successfully used in the management of retroperitoneal fibrosis in various
small trials, although the exact mechanism of its action remains unclear
[46]. However, high doses of
these agents may be required to obtain a response, and relapse may occur when
they are discontinued.
Drainage of the upper urinary tract may be required as a temporary measure
to facilitate improvement in renal function. Percutaneous nephrostomy and
subsequent ureteral stenting are the current preferred approach, providing
short-term relief of symptoms until the effects of appropriate management are
seen. Surgical intervention may be required in patients in whom the
compressive effects of retroperitoneal fibrotic soft tissue are not relieved
using conventional means. The standard surgical approach consists of open
biopsy, ureterolysis, and ureteral transposition (laterally or, preferably,
intraperitoneally) with omental wrapping of the involved ureter. However, this
approach is not without hazard; ureteral devascularization, tears, and
strictures with ureteral leakage or urinary fistula formation occur
frequently. Several authors have reported successful laparoscopic ureterolysis
[47], offering the potential
for less invasive surgical treatment options.
Outcome
The prognosis for patients with benign retroperitoneal fibrosis is
generally considered to be good, depending on the identification and nature of
the underlying cause. Although severe complications such as chronic renal
failure may result, in most instances idiopathic retroperitoneal fibrosis does
not lead to long-term morbidity or affect patient survival. Malignant
retroperitoneal fibrosis, on the other hand, carries a poor prognosis, with a
mean survival of as little as 3–6 months
[7,
10].
Conclusion
Retroperitoneal fibrosis is an uncommon entity for which an underlying
cause is found in less than 30% of cases, with 8% of causes relating to
malignancy. Although the prognosis for idiopathic retroperitoneal fibrosis is
good, patients with malignant underlying causes often have dismal outcomes. CT
and MRI offer superb delineation of the extent and complications of this
disease process, though they fare poorly in the differentiation of benign from
malignant causes. Sonography and scintigraphy are similarly unhelpful.
We have outlined the various imaging appearances of retroperitoneal
fibrosis, illustrating the strengths and weaknesses of each, and stressing the
universal limitation of their failure to allow confident differentiation of
benign from malignant causes. As a result, biopsy with histopathologic
evaluation remains the current mainstay of soft-tissue evaluation.
References
- Kottra JJ, Dunnick NR. Retroperitoneal fibrosis. Radiol
Clin North Am 1996;43
:1259-1275
- Vaglio A, Salvarani C, Buzio C. Retroperitoneal fibrosis.
Lancet 2006;367
:241-251[CrossRef][Medline]
- Albarran J. Rétention rénale par
périurétérite: libération externe de
l'uretère. Assoc Fr Urol 1905;9
:511-517
- Ormond JK. Bilateral ureteral obstruction due to envelopment and
compression by an inflammatory retroperitoneal process. J
Urol 1948;59
:1072-1079[Medline]
- Hohenfellner R. Uncommon forms of periureteritis. Urol
Int 1962;14
:292-309[Medline]
- Dehner LP, Coffin CM. Idiopathic fibrosclerotic disorders and other
inflammatory pseudotumors. Semin Diagn Pathol1998; 15
:161-173[Medline]
- Koep L, Zuidema GD. The clinical significance of retroperitoneal
fibrosis. Surgery 1977;81
:250-257[Medline]
- Webb AJ, Dawson-Edwards P. Non-malignant retroperitoneal fibrosis.
Br J Surg 1967;54
:508-518[Medline]
- Vivas I, Nicolas AI, Velazquez P, et al. Retroperitoneal fibrosis:
typical and atypical manifestations. Br J Radiol2000; 73
:214-222[Abstract]
- Lalli AF. Retroperitoneal fibrosis and inapparent obstructive
uropathy. Radiology 1977;122
:339-342[Abstract]
- Feinstein RS, Gatewood OM, Goldman SM, et al. Computerized
tomography in the diagnosis of retroperitoneal fibrosis. J
Urol 1981;126
:255-259[Medline]
- Brun B, Laursen K, Sorensen IN, et al. CT in retroperitoneal
fibrosis. AJR 1981;137
:535-538[Abstract/Free Full Text]
- Amis ES Jr. Retroperitoneal fibrosis. AJR1991; 157
:321-329[Abstract/Free Full Text]
- Mulligan SA, Holley HC, Koehler RA, et al. CT and MR imaging in the
evaluation of retroperitoneal fibrosis. J Comput Assist
Tomogr 1989;13
:277-281[Medline]
- Brooks AP. Computed tomography of idiopathic retroperitoneal
fibrosis (`periaortitis'): variants variations, patterns and pitfalls.
Clin Radiol 1990;42
:75-79[CrossRef][Medline]
- Degesys GE, Dunnick NR, Silverman PM, et al. Retroperitoneal
fibrosis: use of CT in distinguishing among possible causes.
AJR 1986;146
:57-60[Abstract/Free Full Text]
- Arrive L, Hricak H, Tavares NJ, et al. Malignant versus
nonmalignant retroperitoneal fibrosis: differentiation with MR imaging.
Radiology 1989;172
:139-143[Abstract/Free Full Text]
- Brooks AP, Reznek RH, Webb JAW. Magnetic resonance imaging of
idiopathic retroperitoneal fibrosis: measurement of T1 relaxation time.
Br J Radiol 1990;63
:842-844[Abstract/Free Full Text]
- Yuh WT, Barloon TJ, Sickels WJ, et al. Magnetic resonance imaging
in the diagnosis and follow-up of idiopathic retroperitoneal fibrosis.
J Urol 1989;141
:602-605[Medline]
- Burn PR, Singh S, Barbar S, et al. Role of gadolinium-enhanced
magnetic resonance imaging in retroperitoneal fibrosis. Can Assoc
Radiol J 2002;53
:168-170[Medline]
- Vaglio A, Buzio C. Chronic periaortitis: a spectrum of diseases.
Curr Opin Rheumatol 2005;17
:34-40[CrossRef][Medline]
- Drieskens O, Blockmans D, van den Bruel A, et al. Riedel's
thyroiditis and retroperitoneal fibrosis in multifocal fibrosclerosis:
positron emission tomography findings. Clin Nucl Med2002; 27
:413-415[CrossRef][Medline]
- Vaglio A, Greco P, Versari A. Post-treatment residual tissue in
idiopathic retroperitoneal fibrosis: active residual disease or silent
"scar"? A study using 18F-fluorodeoxyglucose positron
emission tomography. Clin Exp Rheumatol2005; 23
:231-234[Medline]
- Lepor H, Walsh PC. Idiopathic retroperitoneal fibrosis.
J Urol 1979;122
:1-6[Medline]
- Higgins PM, Bennett-Jones DN, Naish PF, et al. Non-operative
management of retroperitoneal fibrosis. Br J Surg1988; 75
:573-577[Medline]
- McDougal WS, MacDonell RC. Treatment of idiopathic retroperitoneal
fibrosis by immunosuppression. J Urol1991; 145
:112-114[Medline]
- Warakaulle DR, Premattilleke I, Moore NR. Retroperitoneal fibrosis
mimicking retrocrural lymphadenopathy. Clin Radiol2004; 59
:292-293[CrossRef][Medline]
- Chan SL, Johnson HW, McLoughlin MG. Idiopathic retroperitoneal
fibrosis in children. J Urol 1979;122
:103-104[Medline]
- Sherman C, Winchester P, Brill PW, et al. Childhood retroperitoneal
fibrosis. Pediatr Radiol 1988;18
:245-247[CrossRef][Medline]
- Doolin EJ, Goldstein H, Kessler B, et al. Familial retroperitoneal
fibrosis. J Pediatr Surg 1987;22
:1092-1094[CrossRef][Medline]
- Meier P, Vogt B, Blanc E. Rethinking the triggering inflammatory
processes of chronic periaortitis. Nephron Exp Nephrol2007; 105
:e17-e23[CrossRef][Medline]
- Aziz F, Conjeevaram S, Phan T. Retroperitoneal fibrosis: a rare
cause of both ureteral and small bowel obstruction. World J
Gastroenterol 2006;12
:7061-7063[Medline]
- Saldino RM, Palubinskas AJ. Medial placement of the ureter: a
normal variant, which may simulate retroperitoneal fibrosis. J
Urol 1972;107
:582-585[Medline]
- Snow BW, Garrett RA. Retroperitoneal fibrosis in children.
Urology 1984;23
:569[CrossRef][Medline]
- Chander S, Ergun EL, Chugani HT, et al. High
2-deoxy-2-[18F]-fluoro-D-glucose accumulation in a case of
retroperitoneal fibrosis following resection of carcinoid tumor.
Mol Imaging Biol 2002;4
:363-368[CrossRef][Medline]
- Rubenstein WA, Gray G, Auh YH, et al. CT of fibrous tissues and
tumors with sonographic correlation. AJR1986; 147
:1067-1074[Abstract/Free Full Text]
- Fagan CJ, Larrieu AJ, Amparo EG. Retroperitoneal fibrosis:
ultrasound and CT features. AJR 1979;133
:239-243[Abstract]
- Liebman RM. Positive gallium scan in retroperitoneal fibrosis.
AJR 1983;141
:949-950[Free Full Text]
- Hillebrand M, Gerstenberg E, Kuntz RM, et al. Gallium-67
szintigrafie bei retroperitonealer fibrose: Indikation, durchfuhrung und
klinische bedeutung. Nucl Med 1996;35
:25-30
- Baker LRI, Mallinson WJW, Gregory MC, et al. Idiopathic
retroperitoneal fibrosis: a retrospective analysis of 60 cases. Br
J Urol 1988;60
:497-503
- Pfammatter T, Hilfiker PR, Kurrer M, Sulser T. Transcaval biopsy of
retroperitoneal fibrosis. Urol Int 1998;60
:258-261[CrossRef][Medline]
- Dash RC, Liu K, Sheafor DH, Dodd LG. Fineneedle aspiration findings
in idiopathic retroperitoneal fibrosis. Diagn
Cytopathol 1999;21
:22-26[CrossRef][Medline]
- Higgins PM, Aber GM. Idiopathic retroperitoneal fibrosis: an
update. Dig Dis 1990;8
:206-222[Medline]
- Bullock N. Idiopathic retroperitoneal fibrosis. (editorial)
BMJ 1988;297
:240-241[Free Full Text]
- Kardar AH, Kattan S, Lindstedt E, et al. Steroid therapy for
idiopathic retroperitoneal fibrosis: dose and duration. J
Urol 2002;168
:550-555[CrossRef][Medline]
- Dedeoglu F, Rose CD, Athreya BH, et al. Successful treatment of
retroperitoneal fibrosis with tamoxifen in a child. J
Rheumatol 2001;28
:1693-1695[Abstract/Free Full Text]
- Fong BC, Porter JR. Laparoscopic ureterolysis: technical
alternatives. J Endourol 2006;20
:820-822[CrossRef][Medline]
- Tang KH, Schofield JB, Powell-Jackson PR. Primary biliary cirrhosis
and idiopathic retroperitoneal fibrosis: a rare association. Eur J
Gastroenterol Hepatol 2002;14
:783-786[CrossRef][Medline]
- Vaglio A, Corradi D, Manenti L, et al. Evidence of autoimmunity in
chronic periaortitis: a prospective study. Am J Med2003; 114
:454-462[CrossRef][Medline]
- Vaglio A, Manenti L, Allegri L, et al. ANCA-positive periaortic
vasculitis: does it fall within the spectrum of vasculitis? J
Intern Med 2002;251
:268-271[CrossRef][Medline]
- Tsai TC, Chang PY, Chen B-F. Retroperitoneal fibrosis and juvenile
rheumatoid arthritis. Pediatr Nephrol1996; 10
:208-209[Medline]
- Okada H, Takahira S, Sugahara S, et al. Retroperitoneal fibrosis
and systemic lupus erythematosus. Nephrol Dial
Transplant 1999;14
:1300-1302[Abstract/Free Full Text]
- Hautekeete ML, Babany G, Marcellin P, et al. Retroperitoneal
fibrosis after surgery for aortic aneurysm in a patient with periarteritis
nodosa: successful treatment with corticosteroids. J Intern
Med 1990;228
:533-536[Medline]
- LeBlanc CM, Inman RD, Dent P, et al. Retroperitoneal fibrosis: an
extraarticular manifestation of ankylosing spondylitis. Arthritis
Rheum 2002;47
:210-214[CrossRef][Medline]
- De la Iglesia Martinez F, Grana Gil J, Gomez Veiga F, et al. The
association of idiopathic retroperitoneal fibrosis and ankylosing spondylitis.
J Rheumatol 1992;19
:1147-1149[Medline]
- Lim CS, Singh Ranger G, Tibrewal S, et al. Sclerosing mesenteritis
presenting with small bowel obstruction and subsequent retroperitoneal
fibrosis. Eur J Gastroenterol Hepatol2006; 18
:1285-1287[CrossRef][Medline]
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Abstract
Introduction
