症例An iliopsoas abscess diﬀerentiated from recurrent colonic cancer
without an invasive surgical procedure using US and CT-guided
percutaneous aspiration and biopsy
Yoshihiro Moriwaki, Jun Otani, Junzo Okuda, Hitomi Zotani, So Kasuga

Abstract: Today, we often encounter iliopsoas abscesses. A 72-year-old male, who had operated for ascending
colon cancer and a local recurrence after 2 years and had survived without recurrence for the next 13 years, waspointed a right iliopsoas lesion suspicious abscess or tumor by plane CT, which was suspected such as abscessor recurrent cancer but not simple hematoma on contrast enhanced CT and MRI images. US showed high echoic
irregular area with unclear margin and with low echoic heterogeneous coarse internal echo pattern, whichindicated a primary or secondary abscess rather than hematoma. We could perform aspiration sampling of material
for bacterial culture and core needle biopsy under real time US and CT guidance, resulting in positive cultureof few anaerobes and no evidence of neoplastic cell. He has been well without detection of any neoplasm for 2years. We could obtain useful information from US/CT-guided aspiration and core needle biopsy for diﬀerential
diagnosis among simple aseptic hematoma, bacterial abscess and neoplastic lesion with/without infection, without
great risks and damage for the patients. The surgical approach requires an invasive procedure with hemorrhage,resulting in the possibility of spreading and implanting infectious materials or neoplastic cells.
Key words: Iliopsoas abscess, differential diagnosis from local recurrence of the right side colon; US/CTguided percutaneous aspiration and biopsy（雲南市立病院医学雑誌

INTRODUCTION

2020; 16（2）:47-51）

using computed tomography（CT）2）. This condition should
be differentiated from a simple iliopsoas hematoma or

Primary iliopsoas abscesses are known as rare conditions

tumourous lesion without infection, in which condition we

requiring appropriate aspiration, drainage and/or invasive

should select therapeutic strategies other than antibiotics.

surgical procedures for sampling bacteria and antibiotic

Here, we present a case of a right iliopsoas abscess in a1）. The invasive surgicalhematoma. We could diﬀerentiate the lesion from recurrent

procedure should be avoided using less invasive diagnostic

colonic cancer using contrast-enhanced CT（CE-CT ）,and therapeutic alternatives. Today, we often encounter thismagnetic resonance imaging（MRI ）and ultrasonography

pathophysiological feature in the differentiating course of（US ）. Furthermore, US- and CT-guided percutaneous

lumbago, lateral abdominal pain and/or fever and chills

aspiration and biopsy were performed, and we could avoid

or invasive anatomical therapy

Department of Surgery, Unnan City Hospital〔96-1 Daito-cho Iida, Unnan, Shimane 699-1221, JAPAN〕
Corresponding author: Yoshihiro Moriwaki, Department of surgery, Unnan City Hospital〔96-1 Daito-cho Iida, Unnan, Shimane699-1221, JAPAN〕
Telephone: 0854-47-7500 / Fax: 0854-47-7501
E-mail: yoshimoriwaki@gmail.com（受付日：2019 年 12 月 1 日，受理日：2020 年 3 月 1 日，印刷日：2023 年 6 月 30 日）

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雲南市立病院医学雑誌

第 16 巻第２号（令和２年３月）
performing invasive surgical procedures.

CASE PRESENTATION
A 72-year-old male Unnan city inhabitant under treatment
for hypertension and hyperlipidaemia visited the outpatient
department of our hospital out of schedule complainingof cough, sputa and pharyngeal pain for one month andright abdominal and lumbar pain for 4 months without
fever. He had undergone curative resection for ascending
colon cancer and reoperation for a local recurrence 2 years
Figure 1 : Abdominal CT images at the out-patient
department showing a right iliopsoas space occupying lesion（yellow dotted circle）

after the primary operation, after which he survived with arecurrence-free interval for the next 13 years. He presented
in good general condition, except for slight right lumbar
pain with tapping and a mild inﬂammatory response in theblood examination, and was told to go back home after
plain CT scanning. However, we found a right iliopsoas
space-occupying lesion with a suspicious abscess or tumour（Figure 1 ）and called him back for admission to ourhospital.
Contrast-enhanced CT on the second hospital day showeda 54 x 32 x 31 mm mass lesion in the right iliopsoas muscle

Figure 2: Contrast enhanced CT on the second hospital day
showing 54x32x31mm of mass lesion in the right iliopsoasmuscle with unclear margin, with central low density areaand staining around mass（yellow dotted circles）

with an unclear margin adjacent to the previous operativeﬁeld, with a central low density area and staining around themass without lymph node swelling around the lesion, which
was suspected to be either an abscess or recurrent coloncancer（Figure 2）. MRI showed a right iliopsoas mass withcentral ﬂuid collection with high intensity around the massin T2 images（Figure 3）. Both imaging ﬁndings indicatedthat the lesion was not a simple hematoma. US showed ahighly echoic iliopsoas irregular area with unclear margins
and a low echoic heterogeneous coarse internal echo patternattached to the iliac bone, which indicated a primary or
secondary abscess rather than a hematoma with aseptic
internal melting（Figure 4）.
Under real-time US guidance, we punctured the mass tosample the contents for bacterial examination, keeping clearof the 2 detectable sized vessels beside the puncture routeto the mass safely and could confirm no vascular injuries
during and after the procedure. We obtained slightly thickFigure 3: MRI on the second hospital day showing a rightiliopsoas mass with central fluid collection with highintensity around mass in T2 images（yellow dotted circles）

bloody ﬂuid and started his treatment as a bacterial iliopsoas
abscess using meropenem. However, we could not obtainevidence of the existence of bacteria in the thick bloodyAn iliopsoas abscess diagnosed using US/CT-guided percutaneous aspiration and biopsy.

49

Figure 4: US showing high echoic iliopsoas irregular area with unclear margin and with low echoic heterogeneouscoarse internal echo pattern（yellow arrow heads）attached to the iliac bone（yellow arrow）

Figure 5: Aspiration sampling of material again and Core needle biopsy（yellow dotted circle）under real time US and CT guidance on the 11thhospital day

fluid obtained from the puncture of the mass. Contrast-

US and CT guidance（Figure 5 ）, resulting in a positiveenhanced CT on the 9th hospital day showed no increase inculture for a few anaerobic Gram negative rods which could

the size of the mass after administration of antibiotics. On

not be identified and inflammatory granulation tissue withthe 11th hospital day, we performed aspiration sampling

no evidence of neoplastic cells. He was discharged homeof material again and core needle biopsy under real-timeon the 22nd hospital day. Although he consulted another50

雲南市立病院医学雑誌

第 16 巻

第２号（令和２年３月）

high-volume hospital, he was well without detection of any

iliopsoas lesion is thought to be less invasive and usefulneoplasm for 2 years.

for diﬀerential diagnosis among simple aseptic hematoma,

DISCUSSION

bacterial abscess and neoplastic lesion with/without
infection.

US-guided percutaneous puncture and/or drainage isReferences

thought to be helpful as a supplement to antibiotic therapy
for a primary bacterial infectious abscess or bacterial１）Tabrizian P, Nguyen SQ, Greenstein A, et al.

abscess secondary to a tumourous lesion or intramuscularManagement and treatment of iliopsoas abscess. Arch

hematoma

3, 4 ）, even if adequate drainage is difficult. In

Surg. 2009;144:946-949.

this case, it was also important to deny the recurrence of２）O u e l l e t t e L , H a m a t i M , F l a n n i g a n M , e t a l .

the previous cancer to avoid invasive procedures. Although

Epidemiology of and risk factors for iliopsoas abscessaspiration sampling of the contents and core needle biopsy

in a large community-based study. Am J Emerg Med.

could not completely deny the existence of bacteria and2019;37:158-159.

malignant cells and were not conclusive diagnostic tools, as３）A b o o b a k a r R , C h e d d i e S , S i n g h B . S u rg i c a lin this case, we could obtain useful information from thesemanagement of psoas abscess in the Humanprocedures without great risks and damage to the patientsI m m u n o d e f i c i e n c y Vi r u s e r a . A s i a n J S u r g .

compared with surgical procedures.

2018;41:131-135.
４）O h a r a N , To m i n a g a O , U c h i y a m a M , e t a l .

The surgical approach for iliopsoas lesions 5, 6 ）Primary iliopsoas abscess successfully treated byusually requires a highly invasive procedure with a large

ultrasonographically guided percutaneous drainage. Jincision and substantial hemorrhage during release of theOrthop Sci. 1998;3:221-224.

retroperitoneal space in the ileac pouch, resulting in the５）Tabrizian P, Nguyen SQ, Greenstein A, et al.

possibility of spreading and implanting infectious materials

Management and treatment of iliopsoas abscess. Archor neoplastic cells.

Surg. 2009;144:946-949.
６）Charalampopoulos A, Macheras A, Charalabopoulos

On the other hand, there are some critical complications

A, et al. Iliopsoas abscesses: diagnostic, aetiologic andin percutaneous aspiration or core needle biopsy, even whentherapeutic approach in five patients with a literatureusing real-time US guidance, such as inadvertent vascularreview. Scand J Gastroenterol. 2009;44:594-599.

and intestinal injuries. However, under real-time US
guidance, gross vascular injuries could be easily avoided.
In our case, we avoided injuries of extended vessels aroundthe lesion, appearing as one of the inﬂammatory responses.
Under adequate preparation, leakage from the small poresof the nonextended healthy intestine injured by ﬁne needles
used during the aspiration procedure may be very small andwill not become the cause of severe peritonitis. It is thought
to be safe and appropriate to prepare for the inadvertentoccurrence of this adverse event using preparation forcolonoscopy, because it is well known that idiopathic
perforation during elective colonoscopy is seldom followed
by severe peritonitis.

CONCLUSIONS
US-guided percutaneous puncture and/or biopsy for an

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An iliopsoas abscess diagnosed using US/CT-guided percutaneous aspiration and biopsy.

USとCTガイド下の低侵襲の経皮吸引細胞診と針生検で大腸癌局所再発と鑑別し得た腸腰筋膿瘍
森脇

要義弘，大谷順，奥田淳三，象谷ひとみ，春日聡

旨：腸腰筋膿瘍は比較的遭遇し易い病態である。症例は，72 歳男性で，上行結腸癌術後 2 年で局所再発に対し再発巣切除術が行われた後 13 年間無再発で経過していた。今回，単純 CTで右腸腰筋内に膿瘍や再発を疑わせる像を認め，造影 CTやMRIも実施されたが，単純な血管腫ではないと思われたが診断には至らなかった。USでは，不整型で境界不明瞭な高エコー，内部は底エコー領域が混在した像として描出され，血管腫より膿瘍が疑われた。USとCTガイド下に培養検体採取，吸引細胞診と針生検を行い，微量検体から嫌気性菌を培養検出し，悪性腫瘍細胞は採取されなかった。その後 2 年間癌再発兆候はない。US/CTガイド下吸引細胞診 / 針生検は，患者への侵襲を押さえながら，無菌性単純血管腫や無菌性血腫，細菌性膿瘍，腫瘍性病変の鑑別に有用な情報を提供する。この部への手術的アプローチは，出血を伴う侵襲的なものとなり，結果的にも感染性物質や腫瘍性物質の散布も懸念される。
キーワード：腸腰筋膿瘍，右側結腸癌局所再発との鑑別，US/CTガイド下経皮的吸引細胞診 / 針生検

雲南市立病院外科
著者連絡先：森脇義弘 雲南市立病院外科〔〒 699-1221
TEL: 0854-47-7500
E-mail: yoshimoriwaki@gmail.com

島根県雲南市大東町飯田 96-1〕