Retroperitoneal-Perinephric Abscess

Clinical History

A 73-year-old diabetic male patient with severe left flank pain and high fever was admitted to our hospital.

Imaging Findings

We present a case of a 73-year-old diabetic male patient who was admitted to our hospital with severe left flank pain and high fever. Physical examination revealed a left flank palpable mass. Laboratory studies showed leukocytosis with a shift to the left and pyuria. A contrast-enhanced CT of the abdomen was performed in order to determine the origin of the clinical and laboratory findings. CT showed a large heterogeneous fluid collection posterior to the left kidney with thick wall and ring enhancement. The collection displaces the left kidney anteriorly and involves the left psoas muscle and the left quadratus lumborum muscle. In addition, the left kidney appeared to have a delayed enhancement(Fig.2d). The patient was diagnosed with retroperitoneal abscess that was surgically drained. Cultures of the purulent fluid showed growth of E. coli ,the same bacterium that was found in the urine cultures. The culture findings along with the kidney enhancement differences where suggestive of kidney related retroperitoneal abscess.

Discussion

The retroperitoneum is a potential space with clearly defined boundaries: between the peritoneum and transversalis fascia lining the posterior abdominal cavity, extending laterally to the edges of the quadratus lumborum muscles, the diaphragms superiorly, and the pelvis inferiorly. The retroperitoneum can be seeded by infections involving numerous organs. The kidneys, ureters, pancreas, abdominal aorta, and inferior vena cava are wholly contained in the retroperitoneum. The ascending colon, descending colon, and duodenum are contiguous with it. Diabetes mellitus, alcohol abuse, malignancy, and glucocorticoid intake may mask the infections by impairing host response. Perinephric abscesses are located between the capsule of the kidney and the Gerota fascia. The abscesses remain confined in this location because of the Gerota fascia. Perinephric abscesses usually occur because of disruption of a corticomedullary intranephric renal abscess, recurrent pyelonephritis, xanthogranulomatous pyelonephritis, or an obstructing renal pelvic stone causing pyonephrosis. Approximately 30% of cases are attributed to haematogenous dissemination of organisms from sites of infection such as wound infection, furuncles, or pulmonary infections. Abscesses can also be caused by ascending urinary tract infection.

Differential Diagnosis List

Final Diagnosis

Retroperitoneal Abscess

URL:	https://www.eurorad.org/case/8204
DOI:	10.1594/EURORAD/CASE.8204
ISSN:	1563-4086