Pediatr Radiol DOI 10.1007/s00247-014-2976-2

CASE REPORT

An idiopathic case of pediatric retroperitoneal fibrosis with extensive magnetic resonance imaging and follow-up Jeremy Egnatios & Cherng Chao & John Naheedy

Received: 7 September 2013 / Revised: 4 February 2014 / Accepted: 12 March 2014 # Springer-Verlag Berlin Heidelberg 2014

Abstract Retroperitoneal fibrosis has seldom been described in the pediatric literature. We present a child who presented with retroperitoneal fibrosis without any associated underlying vascular or inflammatory conditions. This is one of only a few cases of primary idiopathic retroperitoneal fibrosis in a pediatric patient to have been imaged extensively by MRI. Keywords Retroperitoneal fibrosis . Idiopathic fibrosis . Magnetic resonance imaging . Child

Introduction Retroperitoneal fibrosis is an uncommon disease most often seen in men. Difficult to identify and diagnose, retroperitoneal fibrosis can present with a variety of symptoms and degrees of severity, based on location and morphology. It is much less commonly seen in children, where it frequently presents secondary to vasculitis or other disease process associated with a significant inflammatory response [1]. Hydronephrosis and ureteral obstruction are the most common complications of retroperitoneal fibrosis. Almost half of all people with retroperitoneal fibrosis present with elevated erythrocyte sedimentation rate, blood urea nitrogen, and creatinine [2]. Recently delayed enhanced MR imaging has become the preferred method of imaging and monitoring retroperitoneal fibrosis in J. Egnatios (*) School of Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA e-mail: [email protected] C. Chao : J. Naheedy Department of Radiology, University of California-San Diego Health Center, San Diego, CA, USA

adults [3]. However no literature describes this MR technique in children. We present an 11-year-old Caucasian boy who presented to the emergency department with scrotal pain and swelling. Subsequent imaging and workup was consistent with idiopathic pediatric retroperitoneal fibrosis and the boy improved on corticosteroid treatment. This case emphasizes the utility of MRI in evaluating the extent and response to therapy in retroperitoneal fibrosis. Specifically, 15-min delayed post-gadolinium imaging was essential to distinguishing the margins of the implicated areas of fibrosis from normal surrounding tissue. We describe the imaging and histopathological findings of retroperitoneal fibrosis in this case.

Case report An 11-year-old Caucasian boy presented to the emergency department complaining of right scrotal swelling and pain over the course of a week. The boy had no significant medical history or family history of hydrocele, hernia or vascular disorders. Laboratory analysis showed an elevated sedimentation rate of 80 mm (normal: 0–15 mm) and a hematocrit of 35% (normal: 36–47%). His leukocyte count was normal at 8,500/μL (normal: 4.0–10.5 TH/μL). The physical examination was unremarkable. A small right varicocele was seen on scrotal sonography. As part of our institution’s protocol, limited images of the kidneys were obtained and revealed mild right hydroureteronephrosis. A noncontrast CT scan was performed to evaluate for obstructing ureteral calculus. Because a soft-tissue density encasing the retroperitoneum was found, intravenous contrast agent was given for additional CT scanning through the kidneys and retroperitoneum with both standard postcontrast (portal–venous phase) imaging as well as 15-min delayed imaging, for better assessment of the ureters (Fig. 1). These contrast-enhanced studies better demonstrated the diffuse, softtissue density mass encasing the aorta and inferior vena cava

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ƒFig. 1

CT images in an 11-year-old boy with retroperitoneal fibrosis. a Axial noncontrast, (b) postcontrast and (c) 15-min delayed images through the level of the lower pole of the kidneys demonstrate a softtissue mass encasing the aorta and inferior vena cava (solid white arrows). Additionally, a left-side or possibly duplicated inferior vena cava was suspected (black arrow in b). Delayed images highlight the encasement and medialization of the proximal ureters (dashed arrows in c). Protocols: a GE LightSpeed VCT 64-slice scanner, 120 kVp, variable mAs, 5-mm slice thickness, CT dose index (CTDI) 4.32 mGy, dose length product (DLP) 150.28 mGy-cm; b GE LightSpeed VCT 64-slice scanner, 120 kVp, variable mAs, 5-mm slice thickness, 91 cc Optiray 320 (Mallinckrodt, St. Louis, MO, USA), CTDI 4.31 mGy, DLP 168.79 mGy-cm; c GE LightSpeed VCT 64-slice scanner, 120 kVp, variable mAs, 5-mm slice thickness, 91 cc Optiray 320, CTDI 4.19 mGy, DLP 125.26 mGy-cm

were made with the biopsy needle, and the boy tolerated the procedure well and was discharged home shortly thereafter. Histopathological assessment revealed tissue with dense fibrosis consisting predominantly of T cells, B cells and a small number of plasma cells (Fig. 2). Because the histology demonstrated a need for follow-up examinations, a baseline MRI of the abdomen and pelvis was obtained prior to the initiation of therapy. The initial MRI again showed an infiltrating retroperitoneal soft-tissue mass measuring approximately 1 × 4 × 8.5 cm, causing severe narrowing of the proximal portion of the right ureter (Fig. 3). The mass also compressed the inferior vena cava (IVC), which as suspected was shown to be left of the aorta just below the level of the renal veins (versus a duplicated IVC with dominant flow through the left side). The area of fibrosis was hypointense on T1-W imaging and uniformly isointense on T2-W MRI, as described in the literature [3]. In addition to the compression on the ureters and IVC, there was significant mass effect on the gonadal venous drainage, which resulted in significant pelvic vascular congestion (Fig. 4).

from the diaphragmatic crura down through the aortic bifurcation, and resulting in medial deviation of the ureters as well as mild right hydroureteronephrosis. CT-guided biopsy was performed using a 20-G springloaded Bard biopsy gun through a 19-G, 16-cm introducer system (C.R. Bard, Tempe, AZ). Because it was suspected that the boy had a left-side (or perhaps duplicated) inferior vena cava, a right paramedian approach was taken. Nine passes

Fig. 2 Histological slide shows dense fibrosis with scattered fibroblasts and foci of chronic inflammation, predominantly lymphocytes with small numbers of plasma cells. (H&E stain, 200× magnification)

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Fig. 3 Baseline axial MRI images in an 11-year-old boy with retroperitoneal fibrosis. a T1-W fat-suppressed ultra-fast gradient echo postgadolinium and (b) balanced gradient echo images through the level of the lower pole of the kidneys demonstrate a soft-tissue mass encasing the aorta and inferior vena cava (IVC) (arrows). Additionally, a left-side IVC (versus a duplicated IVC with dominant flow through the left side) is confirmed (arrowhead) and appears hyperintense (likely due to sluggish flow related to the vascular compression from the fibrosis). The aorta appears isointense to the soft-tissue mass (b) because of the timing of the image. On the delay, the aorta has nearly completely washed out, while the mass demonstrates progressive accumulation and persistence of contrast agent from the fibrosis

An extensive workup for the cause of retroperitoneal fibrosis was performed. Screening for disorders associated with retroperitoneal fibrosis such as inflammatory bowel disease, lymphoma, systemic lupus erythematosus and HenochSchonlein Purpura were all negative. After exhaustive workup, a diagnosis of primary idiopathic retroperitoneal fibrosis was made. The boy was started on prednisone (15 mg 4 times/ day for 2 months), after which his pain resolved. His erythrocyte sedimentation rate returned to within normal limits. He tolerated the drug regimen without significant complications. Subsequent follow-up MR images at 4 weeks (Fig. 5) and at 10 weeks (Fig. 6) showed substantial interval improvement in the retroperitoneal fibrosis and hydronephrosis, as well as

Fig. 4 Baseline MR images of mass effect in an 11-year-old boy with retroperitoneal fibrosis. a Coronal T2-W image with fat suppression and (b) axial short tau inversion recovery (STIR) image demonstrate hydronephrosis (thin arrow in a) and significant gonadal venous congestion (open arrows) secondary to the mass effect from the fibrosis

near-complete resolution of the pelvic vascular congestion. Interestingly, on follow-up scans the 15-min post-gadolinium contrast-enhanced imaging showed markedly increased conspicuity of the areas of fibrosis relative to the adjacent soft tissues in comparison to standard sequences. The utility of this technique has been described for adults with retroperitoneal fibrosis being evaluated by MR imaging [3].

Discussion Retroperitoneal fibrosis is a rare disease characterized by the proliferation of fibrous tissue in the retroperitoneum. Retroperitoneal fibrosis commonly envelopes the vasculature or prevertebral and presacral areas. Ureteral obstruction is the most common complication [4]. First described by French urologist Joaquin Albarran in 1905, it was later rediscovered and brought to more widespread attention by John Kelso Ormond in 1948, and as a result the eponymous name of this condition is Ormond disease [1]. It was once thought to be

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ƒFig.

5 Four-week follow-up images in an 11-year-old boy with retroperitoneal fibrosis being treated with prednisone. a Axial postgadolinium T1-W fat-suppressed ultra-fast gradient echo MRI demonstrates interval decrease in the soft-tissue mass encasing the aorta and inferior vena cava (IVC) (arrows) as well as less apparent mass effect on the left-side IVC (arrowhead). b Axial T1-W fat-suppressed post-gadolinium image with 15-min delay through the level of the lower pole of the kidneys shows an area of fibrosis that is much more avidly enhancing (arrows), highlighting the utility of obtaining 15-min delayed post-contrast images for the purpose of better identifying fibrotic tissue. c Axial T2-W fat-suppressed image through the pelvis demonstrates near-complete resolution of the pelvic vascular congestion (open arrows). The aorta appears isointense to the soft-tissue mass (b) because of the timing of the image. On the delay, the aorta appears nearly completely washed out and the mass demonstrates progressive accumulation and persistence of contrast material because of the fibrosis

idiopathic but is now more commonly found to be secondary to other conditions. Retroperitoneal fibrosis primarily affects older adults, with an incidence of 1.3 per 100,000 in people older than 40 years [5]. The diagnosis of retroperitoneal fibrosis is made primarily by imaging, with initial sonograms confirmed by CT or MRI. Classically, retroperitoneal fibrosis is visualized under T1weighted MR imaging as hypointense. T2-weighted MR imaging findings vary with disease progression, with intensity related to degree of inflammatory fibrosis and corresponding vascularity and cellularity. A recent literature review showed

Fig. 6 Ten-week follow-up MR images in an 11-year-old boy being treated for retroperitoneal fibrosis. a Axial post-gadolinium T1-W fatsuppressed ultra-fast gradient echo and (b) axial T1-W fat-suppressed post-gadolinium image with a 15-min delay, both through the level of the lower pole of the kidneys. Images demonstrate interval decrease in the soft-tissue mass encasing the aorta and inferior vena cava (IVC) (arrows) as well as less mass effect on the left-side IVC (arrowhead). Again, note the increased conspicuity of the area of fibrosis on the 15-min delayed image (b). The aorta appears isointense to the soft-tissue mass (b) because of the timing of the image. On the delay, the aorta appears nearly completely washed out, while the mass demonstrates progressive accumulation and persistence of contrast material because of the fibrosis

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that MRI is superior to other methods of monitoring disease progression in adults with retroperitoneal fibrosis [3]. Thirty-five pediatric cases of retroperitoneal fibrosis have been described in English literature, with the significant majority occurring in children with associated conditions [6]. The pathogenesis is unclear, but in adults it is often associated with trauma, vasculopathy and autoimmune dysfunction [4]. In pediatric cases, retroperitoneal fibrosis is more commonly seen secondary to pulmonary hyalinizing granuloma, systemic lupus erythematosus and juvenile rheumatoid arthritis [2, 4]. Approximately half of patients presenting with retroperitoneal fibrosis have elevated erythrocyte sedimentation rate, blood urea nitrogen, creatinine and active immunoglobulin levels [2]. Diagnosis is most commonly made by imaging and confirmed by biopsy. Symptoms vary based on extent of the mass effect, but common signs and symptoms include abdominal pain, weight loss, anemia, hypertension and a variety of urinary complications [1]. Idiopathic retroperitoneal fibrosis is most commonly treated with steroids or other immunosuppressive agents, such as azathioprine. Surgical intervention is considered for those whose symptoms do not improve on steroid therapy [4]. If there is obstructive uropathy that does not promptly respond to medical treatment, this is an indication for percutaneous nephrostomy or retrograde placement of nephroureteral stents [7]. To our knowledge, this is only the eighth case of primary idiopathic retroperitoneal fibrosis in a boy without any associated conditions [7]. This case shows an extensive presentation of retroperitoneal fibrosis, with the fibrosis extending as high as the diaphragmatic crura, because the majority of presentations are closer to the sacral promontory. Additionally, from an imaging perspective this case exemplifies the utility of MRI in evaluating the extent and the response to therapy in pediatric retroperitoneal fibrosis. In particular, as recently described for adults with retroperitoneal fibrosis, 15-min delayed postcontrast imaging can be very useful in distinguishing the margins of the involved areas of fibrosis from normal surrounding soft tissues, and it offers superior enhancement for

better monitoring of therapeutic effect on regression of the fibrosis [3]. In light of the excellent results with MR imaging, the authors acknowledge the drawbacks to performing three phases of CT scanning (specifically the unnecessary added radiation dose), and would not endorse this imaging workup for future patients with this presenting condition. In fact, given the added information that MR imaging provides, especially when including the 15-min delays that highlight the fibrosis, the authors would recommend this imaging protocol be implemented prior to any invasive procedure or biopsy in future situations. However, in our case the specific request of the referring physician to carry out the biopsy as soon as the finding was made delayed the MRI. The information provided by MRI could also prove useful prior to planning tissue sampling procedures and follow-up monitoring.

Conflicts of interest None.

References 1. Chou Y, Chang M, Lee H et al (1992) Portal hypertension in a child with retroperitoneal fibrosis. J Pediatr Gastroenterol Nutr 15:444–447 2. Tsai TC, Chang PY, Chen BF et al (1996) Retroperitoneal fibrosis and juvenile rheumatoid arthritis. Pediatr Nephrol 1:208–209 3. Brandt AS, Kamper L, Kukuk S et al (2013) An aid to decisionmaking in therapy of retroperitoneal fibrosis: dynamic enhancement analysis of gadolinium MRI. J Clin Med Res 5:49–56 4. Birnberg FA, Vinstein AL, Gorlick G et al (1982) Retroperitoneal fibrosis in children. Radiology 145:59–61 5. Caiafa RO, Vinuesa AS, Izquierdo RS et al (2013) Retroperitoneal fibrosis: role of imaging in diagnosis and follow-up. Radiographics 33: 535–552 6. Young AS, Binkovitz LA, Adler BH et al (2007) Pulmonary hyalinizing granuloma and retroperitoneal fibrosis in an adolescent. Pediatr Radiol 37:91–95 7. Miller OF, Smith LJ, Ferrara EX et al (2003) Presentation of idiopathic retroperitoneal fibrosis in the pediatric population. J Pediatr Surg 38: 1685–1688

An idiopathic case of pediatric retroperitoneal fibrosis with extensive magnetic resonance imaging and follow-up.

Retroperitoneal fibrosis has seldom been described in the pediatric literature. We present a child who presented with retroperitoneal fibrosis without...
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