Figure 1
US examination of the abdomen
Right kidney hydronephrosis and presence of a hypoechoic zone in the inferior pole of right kidney are noticed
Secondary Iliopsoas Abscess
SectionAbdominal imaging
Case TypeClinical Cases
Authors
Pitta1 X, Karadimou1 V, Boutsioukis1 S, Karatziou1 C, Stergiouda1 T, Michailidis2 N, Termentzis1 G
1 Department of Radiology, General Hospital “Agios Pavlos”, Thessaloniki, Greece.
2 Department of Internal Medicine, General Hospital “Agios Pavlos”, Thessaloniki, Greece
Connected authors
66 years, female
Clinical History
The patient complained of right abdominal pain and limitation of right hip movement for about a week.
She had a clinical history of diabetes mellitus and myelodysplastic syndrome while she was recovered in another hospital for glomerulonephritis two weeks earlier.
Laboratory data showed anemia, thrombopenia, leukocytosis and increased erythrocyte sedimentation rate, creatinine and urea values.
She had a clinical history of diabetes mellitus and myelodysplastic syndrome while she was recovered in another hospital for glomerulonephritis two weeks earlier.
Laboratory data showed anemia, thrombopenia, leukocytosis and increased erythrocyte sedimentation rate, creatinine and urea values.
Imaging Findings
US examination (Fig. 1) revealed right kidney hydronephrosis and the presence of a hypoechoic zone with not well-defined limits in the inferior pole, suggesting an abscess.
The CT examination (Fig. 2) was performed without administration of intravenous contrast medium because of the elevated values of creatinine and urea. Enlargement of the right iliopsoas muscle and the presence of a hypodense lesion in it was demonstrated. Right kidney hydronephrosis and thickening of the renal fascia were also detected.
MRI (Figs. 3 and 4) confirmed the presence of a fluid-filled lesion expanding the iliopsoas muscle with rim enhancement suggestive of iliopsoas abscess. The lesion was extending from the inferior pole of the right kidney to the iliac fossa. It also revealed the presence of small abscess in the inferior pole of the right kidney.
The patients abscess was drained surgically.
The CT examination (Fig. 2) was performed without administration of intravenous contrast medium because of the elevated values of creatinine and urea. Enlargement of the right iliopsoas muscle and the presence of a hypodense lesion in it was demonstrated. Right kidney hydronephrosis and thickening of the renal fascia were also detected.
MRI (Figs. 3 and 4) confirmed the presence of a fluid-filled lesion expanding the iliopsoas muscle with rim enhancement suggestive of iliopsoas abscess. The lesion was extending from the inferior pole of the right kidney to the iliac fossa. It also revealed the presence of small abscess in the inferior pole of the right kidney.
The patients abscess was drained surgically.
Discussion
Iliopsoas abscess is an uncommon condition. Diagnostic delays result in high mortality and morbidity. When there is no obvious source of infection the term primary Iliopsoas abscess is used[1-3]. Primary iliopsoas abscesses can occur in patients with diabetes mellitus, renal failure, immunosuppression and AIDS. Secondary abscesses arise from the direct extension of infection from an adjacent organ. Crohn’s disease is the most common cause. Diverticulitis, appendicitis, ulcerative colitis, colorectal cancer, urinary tract infection or cancer, osteomyelitis, septic arthritis, disk infection, trauma, endocarditis, suppurative lymphadenitis, procedures performed in the groin, lumbar, or hip areas are other causes of secondary iliopsoas abscesses. The most common pathogen of primary psoas abscesess is Staphylococcus aureus (80%), while that of secondary psoas abscesses is usually mixed intestinal floras [2-6].
Iliopsoas abscess is common in the young compared with the elderly and it is more common in males than females [2].
The classic triad, fever, back pain and limitation of hip movement, is present in 30% of the patients. Other symptoms are vague abdominal pain, malaise, nausea and weight loss [2, 3, 6].
Plain radiographic signs of psoas abscess are of limited sensitivity and specificity. Ultrasound of the abdomen is diagnostic in only 60% of the cases as it may demonstrate an anechoic or hypoechoic lesion in the iliopsoas compattment but it cannot identify the cause of the abscess. Also bowel gas can obscure the retroperitoneal space. Computed tomography of the abdomen with contrast is the most efficient and accurate imaging study in diagnosing an iliopsoas abscess. At CT, it manifests as a hypodense lesion causing enlargement of the psoas muscle. After intravenous contrast administration a rim enhancement of varying thickness is noticed. Inflammatory obliteration of surrounding tissue planes, gas bubbles, and bone destruction can be secondary findings [1-6].
MRI findings are similar to CT and consist of a fluid-filled lesion expanding the psoas muscle with rim enhancement after contrast administration [2, 6].
Psoas abscesses should be distinguished from other causes of psoas enlargement, including haemorrhages and tumours. Treatment involves the use of appropriate antibiotics combined, in most cases, with drainage of the abscess through a percutaneous CT-guided or an open technique. Surgical drainage is indicated if there is a contraindication to CT-guided percutaneous drainage or abdominal pathology that requires intervention [1-6].
Although the mortality rate in primary iliopsoas abscesses is 2.4% and in secondary abscesses is 19%, in untreated patients it can reach 100% [2, 3, 6].
Iliopsoas abscess is common in the young compared with the elderly and it is more common in males than females [2].
The classic triad, fever, back pain and limitation of hip movement, is present in 30% of the patients. Other symptoms are vague abdominal pain, malaise, nausea and weight loss [2, 3, 6].
Plain radiographic signs of psoas abscess are of limited sensitivity and specificity. Ultrasound of the abdomen is diagnostic in only 60% of the cases as it may demonstrate an anechoic or hypoechoic lesion in the iliopsoas compattment but it cannot identify the cause of the abscess. Also bowel gas can obscure the retroperitoneal space. Computed tomography of the abdomen with contrast is the most efficient and accurate imaging study in diagnosing an iliopsoas abscess. At CT, it manifests as a hypodense lesion causing enlargement of the psoas muscle. After intravenous contrast administration a rim enhancement of varying thickness is noticed. Inflammatory obliteration of surrounding tissue planes, gas bubbles, and bone destruction can be secondary findings [1-6].
MRI findings are similar to CT and consist of a fluid-filled lesion expanding the psoas muscle with rim enhancement after contrast administration [2, 6].
Psoas abscesses should be distinguished from other causes of psoas enlargement, including haemorrhages and tumours. Treatment involves the use of appropriate antibiotics combined, in most cases, with drainage of the abscess through a percutaneous CT-guided or an open technique. Surgical drainage is indicated if there is a contraindication to CT-guided percutaneous drainage or abdominal pathology that requires intervention [1-6].
Although the mortality rate in primary iliopsoas abscesses is 2.4% and in secondary abscesses is 19%, in untreated patients it can reach 100% [2, 3, 6].
Differential Diagnosis List
Iliopsoas Abscess
Iliopsoas haemorrhage
Iliopsoas tumour
Final Diagnosis
Iliopsoas Abscess
References
[1] Chi-Hsun Hsieh, Yu-Chun Wang, Horng-Ren Yang, Ping-Kuei Chung, Long-Bin Jeng, Ray-Jade Chen (2006) Extensive retroperitoneal and right thigh abscess in a patient with ruptured retrocecal appendicitis: An extremely fulminant form of a common disease. World J Gastroenterol 12(3): 496-499
[2] I H Mallick, M H Thoufeeq, T P Rajendran (2004) Iliopsoas abscesses. Postgrad Med J 80:459–462
[3] Sunita N. Agrawal, Amit J. Dwivedi and Mohammed Khan (2002) primary psoas abscess. Digestive disease and sciences vol. 47, 2103-2105
[4] Parissa Tabrizian, Scott Q. Nguyen, Alexander Greenstein, Uma Rajhbeharrysingh, Celia M. Divino. (2009) Management and Treatment of Iliopsoas Abscess. Arch Surg 144(10):946-949
[5] Eric B. Tomich and David Della-Giustina (2009) Bilateral Psoas Abscess in the Emergency Department. West J Emerg Med 10(4): 288–291
Case information
| URL: | https://www.eurorad.org/case/9529 |
| DOI: | 10.1594/EURORAD/CASE.9529 |
| ISSN: | 1563-4086 |
Figure 2
CT examination of the abdomen
CT examination without administration of intravenous contrast medium showing right kidney hydronephrosis and enlargement of the right psoas muscle with presence of a hypodense lesion.
CT examination without administration of intravenous contrast medium showing enlargement of the right psoas muscle with presence of a hypodense lesion.
CT examination without administration of intravenous contrast medium showing enlargement of the right iliopsoas muscle with presence of a hypodense lesion.
CT examination without administration of intravenous contrast medium showing enlargement of the right iliopsoas muscle with presence of a hypodense lesion.
Figure 3
MRI examination of the abdomen
Post gadolinium T1WI confirming a small abscess in the inferior pole of the right kidney and hydronephrosis.
Post gadolinium T1WI confirming right kidney hydronephrosis and the beggining of a fluid-filled lesion expanding the psoas muscle with rim enhancement suggestive of abscess.
Post gadolinium T1WI confirming the presence of a fluid-filled lesion expanding the psoas muscle with rim enhancement suggestive of abscess.
Post gadolinium T1WI confirming the presence of a fluid-filled lesion expanding the iliopsoas muscle with rim enhancement suggestive of abscess.
US examination of the abdomen
Right kidney hydronephrosis and presence of a hypoechoic zone in the inferior pole of right kidney are noticed
General Hospital \'Agios Pavlos\" Thessaloniki
General Hospital \'Agios Pavlos\" Thessaloniki
CT examination of the abdomen
CT examination without administration of intravenous contrast medium showing right kidney hydronephrosis and enlargement of the right psoas muscle with presence of a hypodense lesion.
General Hospital \'Agios Pavlos\" Thessaloniki
General Hospital \'Agios Pavlos\" Thessaloniki
CT examination without administration of intravenous contrast medium showing enlargement of the right psoas muscle with presence of a hypodense lesion.
General Hospital \'Agios Pavlos\" Thessaloniki
General Hospital \'Agios Pavlos\" Thessaloniki
CT examination without administration of intravenous contrast medium showing enlargement of the right iliopsoas muscle with presence of a hypodense lesion.
General Hospital \'Agios Pavlos\" Thessaloniki
General Hospital \'Agios Pavlos\" Thessaloniki
CT examination without administration of intravenous contrast medium showing enlargement of the right iliopsoas muscle with presence of a hypodense lesion.
General Hospital \'Agios Pavlos\" Thessaloniki
General Hospital \'Agios Pavlos\" Thessaloniki
MRI examination of the abdomen
Post gadolinium T1WI confirming a small abscess in the inferior pole of the right kidney and hydronephrosis.
\"Papageorgiou\" General Hospital
\"Papageorgiou\" General Hospital
Post gadolinium T1WI confirming right kidney hydronephrosis and the beggining of a fluid-filled lesion expanding the psoas muscle with rim enhancement suggestive of abscess.
\"Papageorgiou\" General Hospital
\"Papageorgiou\" General Hospital
Post gadolinium T1WI confirming the presence of a fluid-filled lesion expanding the psoas muscle with rim enhancement suggestive of abscess.
\"Papageorgiou\" General Hospital
\"Papageorgiou\" General Hospital
Post gadolinium T1WI confirming the presence of a fluid-filled lesion expanding the iliopsoas muscle with rim enhancement suggestive of abscess.
\"Papageorgiou\" General Hospital
\"Papageorgiou\" General Hospital
