Retroperitoneal Fibrosis Is Still an Underdiagnosed Entity with Poor Prognosis

Abstract

Background: Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of inflammatory and fibrous retroperitoneal tissue that often encircles abdominal organs including the aorta and ureters. Data on the incidence of this disease are limited. Summary: The disease may be idiopathic or secondary to infections, malignancies, drugs, or radiotherapy. The idiopathic form is an immune-mediated entity and a part of the broader spectrum of idiopathic diseases termed chronic periaortitis, characterized by a morphologically similar fibroinflammatory changes in the aorta and surrounding tissues. Taking into account the dominant symptoms and clinical characteristics of patients with periaortitis, 2 subtypes of disease could be distinguished. The vascular subtype includes patients with nondilated aorta or with inflammatory abdominal aortic aneurysm, both with and without involvement of adjacent structures and with numerous risk factors for atherosclerosis. In the renoureteral subtype, obstructive uropathy manifesting with hydronephrosis and acute kidney injury is the predominant finding. Due to the variety of symptoms, diagnosis of RPF remains challenging, difficult, and often delayed. A series of diagnostic tests should be performed, in order to confirm the diagnosis idiopathic RPF. Laboratory workup includes evaluation of inflammatory indices and immunological studies. A biopsy and histopathological evaluation may be necessary to confirm diagnosis and differentiate the disease. Computed tomography, magnetic resonance imaging, and positron emission tomography are the modalities of choice for the diagnosis and follow-up of this disease. Management of ureteral obstruction, hydronephrosis, and aortic aneurysms often requires surgical evaluation and treatment. The pharmacological treatment of RPF has been evaluated in a few randomized trials and is mainly based on observational studies. Steroid therapy remains the gold standard of treatment. Key Messages: Nowadays, multidisciplinary team approach with clinical and diagnostic experience in both primary and secondary RPF as well as 2 major subtypes should be offered. Centers specialized in rare diseases with collaboration with other units and referral system yield the best possible outcomes.