Retroperitoneal fibrosis with pancreatic involvement - radiological appearance

Abstract

Background: Retroperitoneal fibrosis or Ormond's disease is an uncommon process characterized by fibrous tissue proliferation in the retroperitoneum, usually involving the aorta, inferior vena cava and iliac vessels. Obstructive hydronephrosis is often observed due to ureteral entrapment. This report presents a case of the peripancreatic location of the disease. The role of CT and MRI in establishing diagnosis of retroperitoneal fibrosis in an atypical site is discussed.

Case report: A 52-year-old woman with Hashimoto's thyroiditis was admitted to hospital because of pain suggesting renal colic. The patient was subjected to ultrasound, CT, and MRI which did not confirm urolithiasis but revealed pancreatic infiltration. Partial pancreatectomy, left-sided adrenalectomy and splenectomy were performed. Retroperitoneal fibrosis was diagnosed in the histopathological examination. A few weeks after surgery, a complication such as pancreatitis developed. Repeat CT confirmed it and showed right hydronephrosis secondary to ureteral involvement by a mass adjacent to the common iliac artery (defined as a typical manifestation of retroperitoneal fibrosis). Nephrostomy and conservative treatment improved the clinical state of the patient. No progression of the process was observed in the follow-up examinations.

Conclusions: Atypical retroperitoneal fibrosis remains a diagnostic challenge. Imaging techniques CT and MRI are useful tools for evaluating the extent of Ormond's disease. An unusual distribution of the process (e.g. peripancreatic location reported in this study) requires histopathological assessment to establish the final diagnosis.

Keywords: CT; MRI; fibrosis; retroperitoneum.

Figure 1.

Enhanced CT: enlarged pancreatic tail appears as hypodense compared to normally-enhanced pancreatic body.

Figure 2.

MRI: T1-weighted image revealed a significant enlargement of the pancreatic tail.

Figure 3.

MRI: T2-weighted image showed an enlarged pancreatic tail with a low signal intensity, typical for the pancreatic parenchyma.

Figure 4.

MRI: T2-weighted image in the sequence with fat suppression showed no hyperintense lesion in the region of the pancreatic tail.

Figure 5.

MRI: post-contrast T1-weighted image in the sequence with fat saturation demonstrated a well-delineated tissue around the pancreatic tail, less enhanced than the pancreatic parenchyma.

Figure 6.

Postoperative CT: a soft-tissue mass surrounding the right common iliac artery (with calcifications in the wall of the vessel); dilated ureter next to the mass (arrow).