A male patient 20 years old admitted
to the emergency room complaining of painful swelling in
the left upper thigh since two weeks.
The left upper thigh swelling is
large of a lemon in size; gradually increase in size,
painful with redness of overlying skin.
There was limitation of left lower
limb movement and associated with hectic fever.
The patient has no history of
infection left lower limb, scrotal swelling, anal pain
or ulceration and there is no impulse on cough.
The patient has past history of left
flank and lower back shrapnleses injuries by explosive
Israeli rocket since two years; he was put under
observation and conservative treatment then discharge
from the hospital.
On examination the patient is pale,
toxic looking and dull, there is left iliac fossa
diffuse mass 10×6 cm, deep to the anterior abdominal
muscle, extended below the left inguinal ligament, not
pulsatial, fixed, not tender, rounded edges, regular
surface and you can not get below it.
Also there was swelling in Upper left
thigh (antromedial aspect) 4*5cm, ill defined border,
hyperaemic skin overlying, warm, tender, not pulsitile,
with no impulse on cough and negative fluctuation test.
There are Enlarged left transverse
inguinal group lymph nodes.
Normal left femoral artery and
peripheral branches pulsation and WBCs 13.5 k/ul, Hb 8.2
chest and lumbosacral X-ray are free,
tuberculin test was negative.
U/S abdomen and pelvis revealed huge
retroperitoneal cystic mass with well formed mature
C.T scan with double contrast shows
multiple retroperitoneal cystic masses with well formed
fibrous wall, the fluid has pus density, lying on the
psoas muscle, extended posterior to the rectum just
above the pelvic floor and mild deviation and
compression on the middle rectum and the urinary
The proximal part of the left
external iliac blood vessels is within the wall.
Intravenous pyelography shows neither shifting nor
dilatation of the left ureter.
Conservative treatment was begun
earlier while doing the investigations. U/S guided
drainage was done by wide pore tube 15 F., at first
1500c.c pus was drained then gradually decease in amount
through the following days.
The left upper thigh swelling
disappeared with progressive improvement of general
condition of the patient.
Another C.T scan was done revealed
persistence of retroperitoneal abscesses with incomplete
drainage of the biggest one also.
Open drainage for the retroperitoneal
abscesses was done by left
sided lower oblique abdominal incision [extended left
lumbar incision, retroperitoneal approach].
Multiple abscesses within psoas
muscle fibres, thick wall with distorted anatomy,
difficult to identify the left ureter and left external
iliac vessels, thick pus discharge with derbies.
Complete drainage and irrigation of
the multiple cavities, three pen rose drains where put
in the large cavities and the wound was closed in
The patient postoperatively improved
progressive decrease of the amount of discharge, the
fever and WBCs subsided.
Culture and sensitivity tests from
the pus which had been taken intra-operatively were
U/S abdomen follow up postoperatively
shows regression in size with small negligible amount of
The clinical diagnosis of
abscess is often delayed or
missed because of the insidious onset of symptoms and
the paucity of localizing signs.
This delay in diagnosis and treatment
contributes to a reported overall mortality rate between
22% and 46% 1,2.
The most common presentation includes
pain and tenderness in the lower abdomen or flank and
fever with or without an abdominal mass.
Less commonly, pain may be noted in
the lower back, hip, or thigh.
Psoas sign, which was initially
negative in this patient, was recorded to be positive in
only 50% of patients with
retroperitoneal abscesses involving the psoas
Hip flexion and scoliosis may also be
Other symptoms include rigors,
anorexia, weight loss, malaise, and hip or back weakness4.
Pollock6 described a
characteristic triad of symptoms: diffuse poorly
localized abdominal pain; extreme weakness; and
Laboratory studies in patients with
retroperitoneal abscesses commonly reveal leukocytosis
Urine analysis is frequently normal
or shows sterile pyuria.
Chest X-ray may reveal elevation or
fixation of the diaphragm, pleural effusion, or basal
atelectasis. Abnormal radiographic studies are reported
in 40% to 90% of patients1,2.
Plain abdominal films may show an
abnormal psoas shadow, scoliosis, or a soft tissue mass.
An intravenous pyelogram may
demonstrate ureteric obstruction or deviation of the
retroperitoneal sepsis may produce evidence of
pressure on the left Ureter5.
In this patient their was no
deviation. U/S abdomen and C.T scans are highly useful
in establishing the diagnosis.
Rivera et al7 reported an
uncommon presentation of
as a painful inguinal swelling in a diabetic patient.
Lorimer and Eldus8
reported three cases of invasive clostridium septicum
infection associated with colorectal carcinoma. Haiart
et al9 reported leg pain as the sole mode of
presentation for five cases of diverticulitis.
On occasions intraabdominal
manifestation may remain occult and extra abdominal
manifestation may be the only presenting symptoms.
The aetiology is usually suggested by
the side of presentation.
The left thigh
abscess is associated with sigmoid diverticulitis
and rectal diseases.
The right is associated with caecal
carcinoma and perforated retrocaecal appendicitis.
Peacock JE6 reported a
case of unusual presentation of tuberculosis spondylitis
The disease was complicated by
fistulous involvement of the sigmoid colon which led to
bowel perforation and dissection of the resulting
abscess into the thigh.
In reviewing the reported cases of
thigh abscesses, the route of spread can be broadly
separated into two groups3,4.
Direct soft tissue extension of
infection down the thigh almost always originates from
the rectum below the peritoneal reflection.
The second route of extension of
infection into the thigh is through naturally occurring
defects in the abdominal wall: along the psoas muscle
deep to the inguinal ligament and iliofemoral vessels;
through the femoral canal; through the obturator
foramen; or through the sacrosciatic notch into the
buttock thigh posteriorly.
The first three routes give rise to
an abscess located in the
anterior and medial aspects of the thigh, which was
reported by Rotstein et al 4to be the
commonest (25 patients) in comparison to the posteriorly
situated thigh abscess (5
The diagnosis of a thigh abscess
as such is not difficult, because it usually presents
with the typical signs and symptoms of inflammation and
gas that are reliably noted on X-ray of the soft tissue.
However, determination of the cause
of the infection may be difficult on a clinical basis.
CT scan of the abdomen and thighs
defines the presence and nature of the intra-abdominal
Bacteriologic study of the thigh
abscess may also provide a
clue to the cause.
All cases noted in the literature
yielded enteric organisms, often multiple, when
aspirates from the thigh were cultured. Both the
retroperitoneal abscess and the thigh
abscess must be treated.
In literature, when cases of thigh
abscesses, secondary to intra-abdominal sepsis, were
managed without attention to the underlying etiologic
process, such as by local thigh drainage plus
antibiotics, the mortality was 93%.
If some form of definitive therapy
was added to the local management of the thigh
abscess, such as
appendicectomy, stoma, or debridement, the mortality was
However, the overall mortality rate
was 53%4. A thigh incision is mandatory to
allow direct drainage of the pus and examination of the
viability of the fascia and muscle.
The location of the thigh incision
is best determined by clinical examination assisted by
CT scan findings that can accurately localize the
collection and the gas distribution in the soft tissue.
Abscesses of the thigh are rare and,
although easily diagnosed, their cause is often obscure.
We present a case of thigh
abscess, which resulted from
the extension of intra-abdominal sepsis.
The underlying pathological
abnormality is retroperitoneal
haematomas with secondary infection. Route of extension
of infection into the thigh was through the left femoral
canal and left obturator foramen. Effective treatment of
this condition requires a high index of suspicion based
on a firm knowledge of the pathogenesis and anatomy of
the retroperitoneal space(s).
The overall mortality of this
condition is high, but recognition of an abdominal
source and appropriate treatment combined with local
drainage of the thigh abscess
appear to improve survival.