Perinephric abscess
Background
- An abscess of the perinephric fat that abuts the renal cortex
- Can arise as a complication either a pre-existing pyelonephritis (majority) or from hematogenous seeding
Causative Organisms[1]
Perinephric vs renal abscess
Perinephric | Renal | |
Necrotic Area | Perinephric fat between the renal cortex and Gerota's fascia | Renal parenchyma |
Cause | Pyelonephritis (majority) | Pyelonephritis (vast majority) |
Risk of morbidity | Higher | Lower |
Genitourinary infection
"UTI" frequently refers specifically to acute cystitis, but may also be used as a general term for all urinary infections; use location-specific diagnosis.
- Renal/perirenal
- Ureteral
- Infected urolithiasis
- Bladder
- Acute cystitis ("UTI")
- Chronic cystitis
- Urethra/periurethra
Clinical Features
- Sign/symptoms similar to pyelo (fever, CVAT, dysuria)
- Occurs in setting of ascending infection with obstructed pyelo
Differential Diagnosis
Flank Pain
- Vascular
- Abdominal aortic aneurysm
- Renal artery embolism
- Renal vein thrombosis
- Aortic dissection
- Mesenteric ischemia
- Renal
- Pyelonephritis
- Perinephric abscess
- Perinephric hematoma
- Papillary necrosis
- Renal cell carcinoma
- Obstructive uropathy
- May or may not be due to nephrolithiasis
- Renal infarction
- Renal hemorrhage
- Ureter
- Nephrolithiasis
- Blood clot
- Stricture
- Tumor (primary or metastatic)
- Bladder
- Tumor
- Varicose vein
- Cystitis
- GI
- Biliary colic
- Pancreatitis
- Perforated peptic ulcer
- Appendicitis (appendix may be pushed to RUQ in pregnancy)
- Inguinal Hernia
- Diverticulitis
- Cancer
- Bowel obstruction
- Gynecologic
- Ectopic Pregnancy
- PID/TOA
- Ovarian cyst
- Ovarian torsion
- Endometriosis
- Mittelschmerz or benign ovulatory pain
- GU
- Other
- Shingles
- Lower lobe pneumonia
- Retroperitoneal hematoma, abscess, or tumor
- Epidural abscess
- Epidural hematoma
- Rib contusion/fracture
Dysuria
- Genitourinary infection
- Acute cystitis ("UTI")
- Pyelonephritis
- Urethritis
- Chronic cystitis
- Infected nephrolithiasis
- Prostatitis
- Epididymitis
- Renal abscess/perinephric abscess
- Emphysematous pyelonephritis
- Nephrolithiasis
- Urethral issue
- Urethritis
- Urolithiasis
- Urethral foreign body
- Urethral diverticulum
- Allergic reaction (contact dermatitis)
- Chemical irritation
- Urethral stricture or obstruction
- Trauma to vagina, urethra, or bladder
- Gynecologic
- Vaginitis/cervicitis
- PID
- Genital herpes
- Pelvic organ prolapse
- Fistula
- Cystocele
- Other
- Diverticulitis
- Interstitial cystitis
- Behavioral symptom without detectable pathology
Evaluation
Laboratory Testing
- CBC - Although it is a non-specific finding, a leukocytosis is typically seen.
- Chemistry Panel - Lactic acidosis is a common finding and is seen earlier in the disease course in diabetic patients. Renal insufficiency is also commonly seen as well.
- Urinalysis - Will often show evidence of pyelonephritis, however if the perinephric abscess is secondary to hematogenous spread, the urine could be sterile. Therefore a negative U/A does NOT rule out a perinephric abscess.
- Blood and urine cultures
Imaging
- CT
- Imaging modality of choice
- Sensitivity ~90%.
- Renal ultrasound - A fluid filled mass extending from the renal cortex into the perinephric fat can be seen.
Management
- Antibiotic therapy depends on the suspected cause
- Pyelonephritis (enterobacteriaceae): third generation cephalosporin + quinolone
- Hematogenous (staphylococcus)): vancomycin
- Known to be colonized by ESBL: carbapenem
- Abscess drainage
- Abscess of ANY size requires IR for percutaneous drainage
- If any urological obstruction is suspected (nephrolithiasis, ureterolithiasis, external compression from abdominal cavity, presence of pre-existing ureteral stent), emergent urological consultation should be obtained
Disposition
- Admission
See Also
External Links
References
- ↑ Liu XQ, et al. Renal and perinephric abscesses in West China Hospital: 10-year retrospective-descriptive study. World Journal of Nephrology. 2016 Jan;5(1):108-14.