Idiopathic retroperitoneal fibrosis diagnosed by endoscopic ultrasonography-guided fine-needle biopsy

Abstract

We demonstrate a case, in which endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) was useful for determining the diagnosis of lesions of retroperitoneal fibrosis. In our case, accessing the retroperitoneal lesions by conventional percutaneous biopsy procedures was not feasible due to the difficulty of avoiding the inferior vena cava and ureter. We believe that our case demonstrates a unique approach for performing histological analysis in a challenging case.

Keywords: IgG4‐related disease; endoscopic ultrasonography‐guided fine needle biopsy; retroperitoneal fibrosis.

Figure 1

(a) Computed tomography (CT) revealed right hydronephrosis caused by a soft‐tissue mass surrounding the abdominal aorta and bilateral common iliac arteries (arrow heads). (b) Positron‐emission tomography examination revealed that the lesion was localized at the retroperitoneum. (c) Endoscopic ultrasonography‐guided fine‐needle biopsy (EUS‐FNB) was performed. (d, e, f) Histopathology revealed an inflammatory infiltration with glass‐like fibrous tissue, no malignant lesion, and 10% of the IgG4/IgG plasma cell ratio (d, hematoxylin stain ×600; e, IgG stain ×600; f, IgG4 stain ×600). (g) After treatment with oral prednisolone, the lesion was reduced.