Summary: A 75-year-old man was admitted after 3 days of fever and left
buttock pain. Two years previously, he had undergone low anterior
resection followed by adjuvant chemoradiotherapy for stage III
adenocarcinoma of the rectum. He was diagnosed to have anastomotic
recurrence 14months after the initial surgery. However, he declined
further surgery and elected to receive palliative chemotherapy
instead. Two weeks prior to the current admission, he developed
intestinal obstruction, which necessitated surgical intervention. A
loop of the terminal ileum was found adherent to the pelvic tumor,
which was inseparable from the pelvic side wall. An ileotransverse
bypass and a colostomy were fashioned to alleviate the bowel
obstruction. The symptoms of intestinal obstruction resolved after
surgery, and he was discharged on postoperative day 8.
Summary: Upon admission, erythema and swelling was noticed over the left
buttock and upper lateral thigh region. The area was extremely
tender,and the left hip movement was greatly restricted because of
the underlying pain. The abdominal examination was unremarkable and
the colostomy was well functioning. The recurrent rectal tumor was
evident on digital rectal examination. Blood test showed
leukocytosis (14.9 10
/L). An urgent computed tomography (CT) of the abdomen and pelvis
was performed with administration of oral and intravenous
Lower limb necrotizing fasciitis
Contrast-enhanced CT showed rim-enhancing loculated collections
with air pockets in the left piriformis and glutei (Figure 1)
extending down to the vastus lateralis muscles (Figure 2). There
was intrapelvic extension via the involved left piriformis, which
was inseparable from the recurrent rectal tumor (Figure 1). A
segment of thickened small bowel was intimately related to the
recurrent tumor (Figure3).
Based on the CT ﬁndings, emergency surgery was scheduled.
During exploration, a large abscess was noted over the gluteal
region extending down to the lateral aspect of the thigh. Incision
and drainage of the abscess with debridement of the necrotic
tissues was performed. The necrotic tissue grew Escherichia
coli and Klebsiella sp. However, his sepsis was not
under control, and another surgical debridement was performed 48
hours later (Figure 4). Extensive muscle necrosis was noticed,
which involved the piriformis, gluteal muscles, short external
rotator muscles, and the quadriceps. Moreover, feculent material
was draining through the medial aspect of the piriformis (Figure
4). In view of the extensive muscle involvement and overall poor
prognosis, the patient was put on supportive care, and he died 3
Necrotizing fasciitis is an uncommon but serious soft tissue
infection that is associated with extensive local tissue
destruction, systemic toxicity, and a fulminant clinical course.
More than 500 cases have been reported in the
literature.1 Despite surgical advances and the
introduction of potent antimicrobial agents, mortality rates of 30%
to 60% have been reported.2 The time course and clinical
presentation of necrotizing fasciitis varies. It can progress from
days to weeks with nonspeciﬁc systemic complaints or vague
localizing symptoms. The overlying skin appearance is often subtle
in the early stage, with erythema that may be mistaken as
cellulitis. However, vesicles, bullae, necrosis, or crepitus should
prompt the diagnosis of necrotizing soft tissue
infection.3 Severe pain out of proportion to physical
ﬁndings is an important clue for distinguishing simple
cellulitis from deep-seated soft tissue infection. Lack of natural
boundaries along the fascial planes explains the rapidity of the
spread of infection and the deterioration in clinical
Sometimes, imaging studies including plain radiograph, computed
tomography (CT), or magnetic resonance imaging (MRI) may facilitate
the diagnosis of this surgical emergency. Plain radiographs are
insensitive in the early stage of the disease, as ﬁndings
such as an increase in soft tissue thickness and
opacity4 are similar to those of cellulitis. The
presence of soft tissue gas is characteristic of necrotizing soft
tissue infection, though this is not a universal
ﬁnding.3,5,6 CT is more sensitive than plain
radiographs in detecting soft tissue gas.6 The presence
of soft tissue gas dissecting along fascial planes is suggestive of
necrotizing fasciitis.7In addition, CT can detect
thickening and enhancement offascial layers with or without
ﬂuid collection.8 In our case, CT was a useful
tool to make the diagnosis, to assess the extent of the soft tissue
infection and to ascertain the infectious source by exhibiting the
intrapelvic extension of inﬂammatory changes via the
piriformis muscle. For patients with renal impairment at the time of
presentation, contrast-enhanced CT may not be advisable and MR
canbe an alternative diagnostic adjunct. In general, the presence
of fascial ﬂuid can be better appreciated on fat-suppressed
T2-weighted images than on fat-suppressed gadolinium-enhanced
T1-weighted images.9 However, the sensitivity of MR
exceeds its speciﬁcity, as both inﬂammatory edema and
liquefactive tissue necrosis produce similar MR appearance and,
therefore, the extent of infection can be
overestimated.4,9 In practice, CT or MR is the best
radiological tool of choice to be used in suspected cases of
necrotizing fasciitis to expedite the diagnosis. However, surgical
treatment should never be delayed by radiological imaging.
Necrotizing fasciitis is a rare complication associated with
colorectal malignancy. There are only few reported cases in the
English language literature to date.10-16 Almost all of
these were related to bowel perforation. They may present as
Fournier's gangrene (necrotizing perineal infection 10,
12-14 psoas abscess,11or direct tumor invasion
into the abdominal wall.15 In this case, tumor
perforation should be the underlying cause for necrotizing
fasciitis. The presence of bowel contents draining from the medial
aspect of the left piriformis in this patient signiﬁed
direct communication between the thigh muscles and the recurrent
rectal anastomosis tumor. This might be the result of multiple
courses of chemotherapy, which led to tumor necrosis and subsequent
bowel perforation. In view of the signiﬁcant amount of
feculent material draining from the rectum through the greater
sciatic notch in the presence of fecal diversion (colostomy), we
suspected that there might be an underlying ﬁstula between
the adherent small bowel loop and the recurrent rectal tumor either
as a result of previous radiotherapy or direct tumor invasion. We
believe that the progression of sepsis after the ﬁrst
debridement could be a combined result of inadequate removal of
necrotic tissue and continued spillage of gastrointestinal contents
through the greater sciatic notch.
Necrotizing fasciitis is a rapidly progressing soft tissue
infection. The clinical outcome relies on the clinician’s acumen
and index of suspicion. Cross-sectional imaging techniques can be
used to hasten the diagnosis. Prompt diagnosis followed by early
antimicrobial therapy andadequate surgical debridement are the key
factors in minimizing morbidities and mortality of necrotizing
- Wong CH, Wang YS. The diagnosis of necrotizing fasciitis.
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- Brook I, Frazier EH. Clinical and microbiological features of
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- Bosshardt TL, Henderson VJ, Organ CH Jr. Necrotizing
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- Struk DW, Munk PL, Lee MJ, et al. Imaging of soft tissue
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- Rehman J, Kaynan A, Samadi D, Fleischman J. Air on radiography
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- Trent JT, Kirsner RS. Diagnosing necrotizing fasciitis. Adv
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- Becker M, Zbren P, Hermans R, et al. Necrotizing fasciitis of
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- Miller TT, Randolph DA Jr, Staron RB, et al. Fat-suppressed MRI
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- Dewire DM, Bergstein JM. Carcinoma of the sigmoid colon: An
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- Lam TP, Maffulli N, Chen EH, Chen JC. Carcinomatous perforation
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- Gould SW, Banwell P, Glazer G. Perforated colonic carcinoma
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- Lawrentschuk N, Young AB, Nguyen H. Necrotizing fasciitis: An
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- Gamagami RA, Mostafavi M, Gamagami A, Lazorthes F. Fournier's
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- Ku HW, Chang KJ, Chen TY, et al. Abdominal necrotizing
fasciitis due to perforated colon cancer. J Emerg Med.
- Liu SY, Ng SS, Lee JF. Multi-limb necrotizing fasciitis in a
patient with rectal cancer. World J Gastroenterol.