Acute Kidney Failure in a Young African American Male

Abstract

Retroperitoneal fibrosis (RPF) is a condition characterized by chronic inflammatory and fibrotic changes in the retroperitoneum that can lead to serious complications including kidney failure, mesenteric and limb ischemia, and deep venous thrombosis among others. Affected individuals may present with nonspecific symptomology that would require a high clinical index of suspicion for prompt diagnosis. We herein discuss a case of a young African-American man with recurrent deep venous thrombosis who presents with a 4-week history of constant aching pain of abdomen and back and kidney failure. Initial noncontrast computed tomogram (CT) only revealed mild bilateral hydroureteronephrosis with inflammatory changes but without obvious mass or lymphadenopathy. At the insistence of the renal consulting team to rule out RPF, a CT-urogram was performed which revealed an infiltrative mass encasing the aorta, inferior vena cava, and common iliac vessels. Laparoscopic biopsy revealed dense fibroadipose tissue, lymphocytic aggregates, focal scattered IgG4-positive plasma cells, and fibrin deposition. Patient underwent bilateral nephrostomy placement and empirical corticosteroid therapy with resolution of kidney failure. Our case illustrates a classic presentation of RPF with relatively benign findings on noncontrast CT that could have been missed if clinicians did not keep a high index of suspicion for the condition.

Figure 1

Initial imaging studies. Left: renal ultrasound at presentation revealed moderately enlarged kidneys with increased renal cortical echogenicity and mild bilateral hydronephrosis. Right: abdomen and pelvis computed tomogram without contrast revealed mild inflammatory changes without lymphadenopathy.

Figure 2

Abdomen and pelvis computed tomogram with intravenous contrast revealed mild bilateral hydroureteronephrosis with point of obstruction at the level of distal abdominal aorta and inferior vena cava. There was an ill-defined, infiltrative soft tissue mass encasing both aorta and IVC (approximately 7.2 cm). The mass appeared to infiltrate along the bilateral proximal common iliac vessels.

Figure 3

Follow-up abdomen and pelvis computed tomogram with and without intravenous contrast 4 months following a course of corticosteroid therapy revealed significant reduction in the soft tissue mass (approximately 4 cm in diameter compared with 7 cm at presentation).