Type:
Educational Exhibit
Keywords:
Aneurysms, Education, Diagnostic procedure, CT-Angiography, Ultrasound, CT, Arteries / Aorta, Abdomen, Inflammation, Haematologic diseases, Retroperitoneum
Authors:
M. Cruz, C. Ferreira, P. G. Oliveira, E. Pinto, F. Caseiro Alves; Coimbra/PT
DOI:
10.1594/ecr2018/C-2428
Background
Retroperitoneal fibrosis (RPF) comprises a range of diseases characterized by the proliferation of aberrant fibroinflammatory tissue in the retroperitoneum.
The idiopathic form accounts for more than two thirds of the cases,
with the remaining third being secondary to other factors such as neoplasms,
drugs,
infection,
retroperitoneal haemorrhage,
radiation therapy and proliferative diseases.
Idiopathic Retroperitoneal Fibrosis (also known as Ormond's disease) is a rare condition,
with a prevalence of 1.3 per 100000 population.
Traditionally, it was considered an excessive local inflammatory response to the antigens expressed on atherosclerotic plaques of the aorta.
However,
current evidence shows that Idiopathic RPF is more likely to represent a manifestation of a systemic inflammatory or auto-immune disease (with atherosclerosis as a predisposing condition/trigger) rather than simply a local reaction.
The usual presence of constitutional symptons,
positive antibodies,
elevated acute phase reactants and association with diverse systemic auto-immune or inflammatory diseases (eg.
Lupus,
Wegener granulomatosis or ankylosing spondylitis) support this etiopathogenic explanation.
Chronic periaortitis and perianeurysmal RPF,
which are more common in men,
are often included under the umbrella of Idiopathic RPF (as it is done in this article),
hence the male predilection of this disease.
Malignant RPF accounts for 10% of the cases and represents the most relevant differential diagnosis due to its poor prognosis.
It results from the desmoplastic response to retroperitoneal metastases (mainly from the breast,
colon,
stomach,
lung,
thyroid or genitourinary tract) or retroperitoneal primary tumors (such as lymphomas and retroperitoneal sarcomas).
Carcinoid tumors may induce RPF without metastasizing to the retroperitoneum,
owing to the release of serotonin and other profibrogenic growth factors.
Clinically,
RPF usually presents with nonspecific signs and symptoms such as poor-localized abdominal or back pain,
anorexia and low-grade fever.
When the ureters are involved (which happens in more than 56% of the cases) the clinical findings range from acute obstructive uropathy to chronic kidney disease.
Less frequently,
lower extremity edema may occur due to extrinsic compression of retroperitoneal lymphatic vessels and veins.
The clinical and laboratory findings of Idiopathic and Secondary RPF often overlap,
thus showing limited utility in differentiating both forms.
Imaging has a major role in the differential diagnosis between:
- Idiopathic and benign secondary forms of RPF,
which have a relatively good outcome;
- Malignant forms of RPF, generally associated with a poor prognosis.