RETROPERITONEAL FIBROSIS WITH PERINUCLEAR ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES AND A LONGITUDINALLY EXTENDED PERIAORTIC SOFT-TISSUE STRUCTURE ON CT

A 63-year-old woman showed positive perinuclear antineutrophil cytopla smic antibodies (pANCA) and presented with an interesting CT finding o f a periaortic soft-tissue structure seen as a rind of tissue surround ing the aorta, extending longitudinally from descending thoracic aorta to bilateral common iliac arteries which was compatible with an early stage of retroperitoneal fibrosis (RPF). Both pANCA titers and a peri aortic mass volume were reduced following corticosteroid treatment, No cases of RPF with a periaortic mass associated with pANCA have been d escribed. Our findings of RPF with pANCA positivity may enlarge the gr oups of ANCA-associated diseases.