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COLON 321
with prior resected hepatic metastases was 34.1% and was not statistically dierent from that of the patients without hepatic metastases.
In a recent publication, Onaitis etal reviewed the experience at
Duke Medical Center and Memorial Sloan Kettering Cancer Center. ree hundred seventy-eight patients who underwent pulmonary resection for colorectal metastases between 1998 and 2007
were identied. e rectum was the primary site of disease in 52%,
with the le colon accounting for 26% and right colon 16%. Fortyfour percent of patients in this series had undergone resection of
extrathoracic metastasis prior to lung surgery. e median diseasefree interval was 24 months. Sixty percent of patients had a solitary
metastasis resected, twenty percent had two metastases resected,
10% had three metastases resected, and 10% had four or more
metastases resected. Overall 3-year survival was 78%, but 3-year
disease-free survival was only 28%. Multivariate analysis showed
that age younger than 65 years, female sex, a disease-free interval
of less than 1 year, and more than three metastases were independent predictors of recurrence. None of the 44 or more patients with
three or more metastases and a disease-free survival of less than
1 year was cured. e large number of patients with prior resection of extrathoracic metastases diers from many other series and
reveals the diculty in comparing these results across institutions
and populations. It should be noted that in the group of patients
undergoing surgical resection by thoracoscopy (VATS), no perioperative deaths occurred.
It is apparent from prior single and multiple-institution studies
that a variety of preoperative factors correlate with better long-term
survival. ese factors include a longer disease-free interval from
the time of colon resection, fewer metastatic lesions, lower prelung
resection CEA, and absence of intrathoracic lymph node involvement. In an attempt to mitigate single-institution bias and obtain
larger numbers, retrospective multi-institution reviews have been
performed. Pfannschmidt et al reviewed articles published aer
1990 involving the surgical treatment of at least 40 patients. Fifteen studies were found, reporting a 5-year survival between 40%
and 68% aer resection of lung metastases. Five-year disease-free
survival was between 19.5% and 34.4%. e perioperative mortality
rate ranged from 0% to just 2.4%. (e low mortality numbers may
illustrate the highly selected nature of retrospective reviews because
institutions with high mortality rates are less likely to publish their
data.) e studies in general found improved survival with metachronous presentation of metastasis, a longer disease-free interval, and the presence of more than one metastasis. e presence
of intrathoracic lymph node metastasis was a negative predictive
factor in two of the studies but was not a negative predictive factor
in ve studies.
Another meta-analysis reported in 2013 focused on surgical studies of more than 40 patients published since 2000. Most of the studies
had between 40 and 80 patients. e meta-analysis included 25 studies with a total of 2925 patients, and overall 5-year survival ranged
from 27% to 68%. Factors associated with increased risk of death aer
resection of lung metastasis were a short disease-free interval (hazard ratio [HR], 1.59; condence interval [CI], 1.27-1.98), multiple
lung metastases (HR, 2.04; CI, 1.72-2.41), intrathoracic lymph node
involvement (HR, 1.65; CI, 1.38-2.02), and pre–lung resection CEA
level (HR, 1.91; CI, 1.57-2.32). It should be noted that only 14 to 19 of
the studies were used for each risk factor analysis because not every
variable was described in each of the 25 studies. Nonetheless, this
is one of the most comprehensive and recent studies incorporating
multiple prior retrospective single-institution studies.
LUNG AND LIVER METASTASIS
In approximately 5% to 10% of patients with colorectal carcinoma,
both lung and liver metastases will develop. In the multicenter retrospective review by Pfannschmidt etal, four series published since
1990 detailed the outcomes of surgical resection of liver and lung
metastasis. e 5-year survival rates were between 31% and 60%. In
general, no dierences were noted in the survival between patients
with metachronous or synchronous presentation of liver and lung
metastases. One study noted that solitary liver metastases, age
younger than 55 years, and a disease-free interval of 1 year or more
between the two metastatic sites were favorable.
In the meta-analysis by Gonzalez etal, 25% of patients undergoing lung metastasis resection had previously resected liver metastases, and 7 of the 25 studies described their results. Five-year
survival aer hepatic and lung resections ranged from 11% to 61%.
Previously resected liver metastasis was not associated with a worse
5-year survival when these seven studies were grouped together and
analyzed. It is very possible that these highly selected patients were
referred by oncologists and accepted by the surgeon because they
were in better than average physical condition with favorable oncologic factors.
SURGICAL APPROACH
A variety of surgical approaches are available for resection of metastatic disease to the lungs. A thoracotomy involves an incision
8 to 14 cm in length, with division of the latissimus dorsi muscle
and spreading of the ribs. A sternotomy can be used for bilateral
resections, although certain anatomic resections are dicult with
this approach (i.e., a le lower lobectomy). A clamshell incision
(bilateral anterior thoracotomies with division across the sternum)
is rarely used for bilateral resection of colorectal metastases. Full
recovery from each of these incisions is typically 4 to 6 weeks. A
minimally invasive approach involving use of an endoscopic camera
typically involves three incisions, each 2 cm in length. For anatomic
resections (a lobectomy or segmentectomy), one of the incisions is
enlarged to 4 to 6 cm. Full recovery typically occurs in 2 to 3 weeks.
Propensity-matched analyses of equivalent patients undergoing
lobectomy via VATS versus a thoracotomy has shown fewer complications and shorter median length of stay (4 vs. 6 days) with the
VATS approach.
e surgical approach to resection of metastatic disease to the
lungs is debated. At issue is whether exploration should be unilateral or routinely bilateral (either to permit simultaneous resection
of known disease or to explore for radiographically occult disease)
and whether exploration should be performed in an open fashion,
via thoracotomy or sternotomy (allowing for manual palpation), or
by VATS (allowing limited palpation). Arguments in favor of larger
incisions that permit bimanual palpation suggest that the approach
permits detection and resection of radiographically occult lesions
that cannot be palpated with the tip of a nger, as would be done
with a VATS approach. In one study not limited to colorectal metastasis, 10 of 57 patients had malignant nodules found at thoracotomy
that were not seen on preoperative computed tomography (CT). In
another study, patients underwent VATS exploration followed by
a planned thoracotomy. In 5 of 17 patients, additional disease was
found at thoracotomy. It must be noted, however, that both of these
studies were conducted by groups not highly trained in the minimally
invasive VATS approach. Additionally, with newer 64-slice helical CT
and ne cuts, virtually all lesions palpable at thoracotomy should
be visible on CT. It is known that, with regard to patients with lung
cancer, most concomitant, tiny (<4 mm) lesions are not malignant.
Aggressive resection of all such tiny lesions may do more harm than
good, especially because resection of central lesions usually requires
a lobectomy.
In six of seven articles reviewed comparing a VATS approach
with the open approach, no dierence in survival was seen. In one
of the articles, more complications were noted following a thoracotomy than with VATS. In the review of the Duke Medical Center and
Memorial Sloan Kettering Cancer Center experience, no dierence
was seen in recurrence-free survival between the VATS and open
approach aer controlling for all other variables.
ColoreCtal Metastases to the lung322
DEVELOPMENT OF A PROSPECTIVE RANDOMIZED TRIAL: THE PULMONARY METASTASECTOMY IN COLORECTAL CANCER TRIAL
Although numerous retrospective single-institution reviews and several cross-institutional reviews have shown encouraging results in
what are likely highly selected patients, only a prospective randomized trial can truly evaluate the benets of surgical resection of pulmonary metastases. For example, the conclusion drawn by Onaitis
etal that resection should not be oered to patients with three or
more metastases and a disease-free interval of less than 1 year (there
were no long-term survivors in their series) may or may not apply
to other patients at other institutions. e drawback of any prospective randomized trial is that conclusions will need to be limited
to patients who t the inclusion criteria, with care to apply these
ndings to similar patients outside the relatively rigid criteria. e
Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) prospective trial has accrued more than 160 patients, with about a third
agreeing to randomization to observation versus resection. PulMiCC
is a two-stage trial, with the rst stage allowing accrual and registration even before randomization. Patient factors such as age, tumor
and node status of the original tumor, disease-free interval, and CEA
level are recorded. All patients are followed up even if they do not
wish to be randomized. At the second stage, patients who agree are
randomized to surgical resection or observation, with many of the
decisions le to the discretion of the clinicians. For instance, either
thoracotomy or VATS is allowed. More details can be obtained at
the ClinicalTrials.gov Web site (https://clinicaltrials.gov/ct2/show/
NCT01106261).
CONCLUSION
Surgical resection of colorectal carcinoma metastatic to the lung
has been practiced for more than 100 years. Retrospective studies of
selected patients document very low morbidity and mortality and a
5-year survival in the range of 40% to 50%. Survival appears to depend
upon the number of metastatic lesions, disease-free interval, and the
presence of intrathoracic nodal disease. Long-term survival can be
achieved in patients with both hepatic and pulmonary metastases
who undergo surgical resection. Unfortunately, current data do not
allow us to determine with certainty which patients with favorable or
unfavorable characteristics will benet from resection. Added information from an ongoing prospective randomized trial may provide
more clarity with regard to treatment recommendations.
S u g g e S t e d R e a d i n g
Cerfolio RJ, McCarthy T, Bryant AS. Non-imaged pulmonary nodules dis-
covered during thoracotomy for metastasectomy by lung palpation. Eur J
Cardiothorac Surg. 2009;35:786–791.
Fiorentino F, Treasure T. Pulmonary metastasectomy for colorectal cancer:
making the case for a randomized controlled trial in the zone of uncertainty. J orac Cardiovasc Surg. 2013;146(4):748–752.
Girard P, Ducreux M, Baldeyrou P, et al. Surgery for lung metastases
from colorectal cancer: analysis of prognostic factors. J Clin Oncol.
1996;14(7):2047–2053.
Gonzalez M, Poncet A, Combescure C, etal. Risk factors for survival aer
lung metastasectomy in colorectal cancer patients: a systematic review and
meta-analysis. Ann Surg Oncol. 2013;20:572–579.
Inoue M, Ohta M, Iuchi K, etal. Benets of surgery for patients with pulmonary
metastases from colorectal carcinoma. Ann orac Surg. 2004;78:238–244.
Miller G, Biernacki P, Kemeny NE, etal. Outcomes aer resection of synchro-
nous or metachronous hepatic and pulmonary colorectal metastases. J Am
Coll Surg. 2007;205:231–238.
Molnar TF, Gebitekin C, Turn A. What are the considerations in the surgical
approach in pulmonary metastasectomy. J orac Oncol. 2010;5:S140–
S144.
Mutsaerts EL, Zoetmulder FA, Meijer S, etal. Long term survival of thora-
coscopic metastasectomy vs metastasectomy by thoracotomy in patients
with a solitary pulmonary lesion. Eur J Surg Oncol. 2002;28:864–868.
Onaitis M, Petersen R, Haney J, etal. Prognostic factors for recurrence af-
ter pulmonary resection of colorectal cancer metastases. Ann or Surg.
2009;87(6):1684–1688.
Paul S, Altorki N, Sheng S, etal. oracoscopic lobectomy is associated with
lower morbidity than open lobectomy: a propensity-matched analysis
from the STS database. J orac Cardiovasc Surg. 2010;129:366–378.
Pfannschmidt J, Homan H, Dienemann H. Reported outcome factors for
pulmonary resection in metastatic colorectal cancer. J orac Oncol.
2010;5:S172–S178.
Saito Y, Omiya H, Kohno K, etal. Pulmonary metastasectomy for 165 patients
with colorectal carcinoma: a prognostic assessment. J orac Cardiovasc
Surg. 2002;124(5):1007–1013.
Treasure T, Falloweld L, Lees B, etal. Pulmonary metastasectomy in colorec-
tal cancer: the PulMiCC trial. orax. 2012;67:185–187.
N
C T
Angelle M. Gelvin and Guy R. Orangio
INTRODUCTION
Nonepithelial tumors of the colon and rectum are rare and represent
fewer than 1% of all neoplasms of the colon and the rectum. ey
can be categorized as benign or malignant. In this chapter we will
briey discuss benign lymphoid hyperplasia, lipomas, and leiomyomas, as well as leiomyosarcoma and the primary lymphomas of the
colon and rectum. A large portion of the chapter will address cavernous hemangiomas of the colon and rectum. Neurobromas and
rhabdomyosarcomas are extremely rare lesions; only nine cases
of rhabdomyosarcoma have been recorded in the world literature.
Endometriosis and the neuroendocrine tumors are discussed in
other chapters in this text.
BENIGN NONADENOMATOUS LESIONS OF THE COLON AND RECTUM
Benign Lymphoid Hyperplasia
A benign lymphoid polyp is an aggregation of lymphoid tissue with
a covering of normal mucosa. ese lesions are most common in the
rectum and the distal sigmoid, where they can be single or multiple, broad based, or have a short pedicle. ey are homogeneous in
appearance and are usually pale. ese lesions are usually small—2 to
4 mm in diameter—but sometimes mucosa-associated lymphoid tissue can measure several centimeters. Lymphoid hyperplasia is more
prominent in children and young adults, in whom the polyps are
numerous and can mimic polyposis. In daily practice, lymphoid polyps are removed during colonoscopy because they are dicult to differentiate from small adenomas or serrated polyps. is is especially
the case when polyp detection rate is an important quality indicator
for colonoscopy. Usually, the pathologist makes the diagnosis. Benign
lymphoid polyps need no follow-up and carry no risk.
Lipomas
Although lipomas are the second most common neoplasm of the
colon aer adenomas, they are uncommon, with an incidence of less
than 1%. Gender distribution is equal, and the average age at diagnosis is 62.4 years. Lipomas are submucosal lesions ranging in size from
0.5 mm to larger than 6.5 cm. ey can be pedunculated or sessile
and are most oen found in the right colon, followed by the transverse colon, sigmoid colon, and rectum. Although most lipomas are
asymptomatic and are found incidentally, they can cause intermittent
bowel obstruction (if the lipoma is near the ileocecal valve), colocolonic intussusception, or prolapse through the rectum.
e typical endoscopic appearance of a submucosal lipoma is a
yellowish, smooth polyp with a broad base or a short, thick stalk. e
mucosal pit pattern is endoscopically normal, although the submucosal position of the lipoma causes stretching of the mucosa, allowing
the endoscopist to see the normal blood vessels. e “pillow sign” is
the classic endoscopic diagnostic maneuver. Biopsy forceps push on
the center of the presumed lipoma, which indents and then gradually
regains its shape, much like a pillow does when it is poked. A supercial biopsy of a lipoma yields only normal mucosa. However, when
a diathermy snare is used to remove overlying mucosa, fat protrudes
from this site. An important dierential, especially in right-sided
lipomas, is a carcinoid tumor. is tumor also looks yellow, but in
contrast to lipomas, it is hard and xed, with no “pillow sign.”
Treatment
Treatment of lipomas of the colon and rectum is dictated by the
clinical presentation. Most asymptomatic lipomas are not treated, but
their existence and position are noted. Treatment of a symptomatic
has been made, the lipoma can be removed with a diathermy snare
en toto or in a piecemeal fashion. An innovative technique for excision of larger lipomas of the colon and rectum has been described.
e diathermy snare is placed around the lipoma, and the snare is
gradually tightened. is maneuver ruptures the lipoma through the
mucosa, thus allowing visualization and easier excision of the lesion.
Only an experienced colonoscopist should attempt this technique
and piecemeal excision of larger lipomas. Because of their high fat
content, lipomas resist conduction of electricity more than do adenomas. More current is required for snaring, and the risk of perforation
is greater. Most lipomas should be le alone.
Patients presenting with intussusception, obstruction, or bleeding
from a lipoma require surgery aer stabilization and resuscitation.
When colonic obstruction is present or when a lipoma is ulcerated
with inconclusive results of biopsies, then the lesion should be considered malignant and resected with oncologic technique.
CAVERNOUS HEMANGIOMA
Phillips rst described hematochezia from an intestinal hemangioma in
1839, and to this date only about 300 cases have been recorded in the literature. e rectosigmoid is the most common site of cavernous hemangioma of the gastrointestinal tract. In about 80% of cases the patient
presents with anemia and recurrent, painless, bright red rectal bleeding.
323
NoNepithelial ColoreCtal tumors324
A life-threatening gastrointestinal hemorrhage is rare but may require
an emergency abdominoperineal resection (Table 65-1). A high index
of suspicion is required for the surgeon to make the correct diagnosis.
Characteristic Features
Hemangiomas of the gastrointestinal tract are classied as multiple
phlebectasias, capillary hemangiomas, and cavernous hemangiomas.
Most are cavernous, in which there are large, thin-walled vascular
channels without true encapsulation, and typically with more smooth
muscle bers than capillary lesions. e pathogenesis of cavernous
hemangiomas is a dynamic process of budding from ectopic mucosal
implants of mesodermal tissue. is process of budding inltration
explains the transmural and mesenteric involvement of these lesions.
Cases of local inltration into the uterus, urinary bladder, and sacrum
have been reported. Figure 65-1 shows a rectal cavernous hemangioma invading the perirectal fat in a 3-year-old boy, illustrating thickening of the rectal wall and mesorectum and invasion into the pelvic
wall. ree years aer resection he presented with a recurrence of the
TABLE 65-1: Cavernous Hemangiomas of the Colon
and Rectum
Sex Age, yr Location Operation Follow-up, yr
Female 49 Rectosigmoid Coloanal* 10
Male 46 Rectosigmoid Proctosig-
moidectomy
10
lesion involving not only the right buttock but the spinal canal near
the cauda equina. He had a tender, right ischiorectal mass and associated anemia. Clinically, the mass measured 8 cm × 5 cm × 5 cm, was
hard, and felt like a “bag of marbles.” A computed tomographic (CT)
scan revealed a recurrent cavernous hemangioma of the ischiorectal
fossa, pelvic wall, and sacrum (Fig. 65-2). Selective angiography was
performed and indicated internal iliac origin and spinal cord plexus
origin. A magnetic resonance image of the spinal cord indicated that
the cauda equina was involved (Fig. 65-3). A multidisciplinary team
including an interventional radiologist, pediatric neurosurgeon, and
colorectal surgeon decided not to embolize or surgically approach this
lesion because the child had minimal symptoms. We also believed that
arterial embolization was too dangerous because of the vessels of origin. Part of the lesion, involving the ischiorectal fossa, had spontaneously thrombosed, and this patient still has no abnormal neurologic
ndings. is young man is now 22 years old and living a normal life.
He still has the same persistent yet asymptomatic recurrence of the
cavernous hemangioma involving the ischiorectal fossa, the bladder,
and the feeding vessel from the spinal cord. A recent review showed
that the radiographic appearances have not changed.
Male 23 Rectosigmoid Coloanal* 9.5
Male 3 Rectosigmoid Coloanal* 6
Female 7 Sigmoid Sigmoid resec-
5
tion
Male 63 Rectosigmoid Abdomin-
operineal
Postoperative
mortality
resection
*Low anterior resection, distal mucosectomy, hand-sewn coloanal pullthrough anastomosis.
FIGURE 65-2 A computed tomographic scan illustrating a recurrent
cavernous hemangioma of the pelvic wall and ischiorectal fossa 3 years
after resection of the primary lesion of the rectum.
FIGURE 65-1 A computed tomographic scan illustrating thickening of
the rectal wall and mesorectum and invasion into the pelvic wall.
FIGURE 65-3 A magnetic resonance image of the spinal cord showing
cavernous hemangioma of the cauda equina area.
COLON 325
e clinical triad of intermittent hematochezia, multiple ectopic
phleboliths on radiographs, and cutaneous hemangiomas should alert
the physician to the presence of an internal hemangioma as the cause
of gastrointestinal hemorrhage. An important association between
cutaneous and mucous membrane hemangiomas has been found
in these patients. Lesions are usually seen on the skin, lips, mouth,
tongue, pharynx, or perianal skin. Cutaneous lesions were present in
three of our six cases. Hematochezia was the presenting symptom in
all of our cases and is found in 75% of the reported cases. is hemorrhage is usually intermittent, but it becomes progressively more severe
with each successive bleeding episode. Bleeding usually begins at an
early age and progresses through life. ese patients can also present
with intestinal obstruction and tenesmus as the initial symptoms.
e diagnosis of bleeding internal hemorrhoids is the most common diagnostic error. Some patients have had multiple hemorrhoidectomies for control of bleeding. Pathognomonic endoscopic ndings
are dilated submucosal tumors that are typically so and range in
color from deep wine to plum. ey collapse upon insuation, revealing dilated, edematous vascular channels. A biopsy is contraindicated.
Laboratory abnormalities may include anemia, thrombocytopenia,
debrination, consumption coagulopathy, and depressed levels of
factors V and VIII. Radiologic studies are helpful. Multiple ectopic
phleboliths in clusters in the pelvis can be demonstrated in 50% of
cases. A preoperative CT scan is important to dene the extent of the
lesion and possible local invasion into other pelvic structures (Fig.
65-4). Mesenteric angiography is essential for dening the arterial
and venous origins of the lesions (Figs. 65-5 and 65-6). A colonoscopy
is indicated preoperatively to dene the anatomic extent of the lesion
and nd any synchronous lesions.
Treatment
Surgery is the treatment of choice. In untreated patients, the mortality rate is 50%. Attempts at mesenteric ligation or embolization, sclerosis, or local excisions oen fail to deal with the symptoms. Surgeries
include limited resection, low anterior proctosigmoidectomy with
colorectal anastomosis, a modied Parks coloanal pull-through procedure, or abdominoperineal resection with end colostomy. Sphincter-saving procedures should be the primary surgical option. Surgery
is best performed when the patient is not actively hemorrhaging.
Intravenous vasopressin can help decrease the rate of hemorrhage
in order to stabilize the patient for surgical intervention. Restorative
resection was possible in ve of our six patients (see Table 65-1) and
has now been performed using a minimally invasive technique.
Surgery (Laparotomy/Laparoscopic)
e patient is placed in the perineolithotomy position. e important
technical considerations are early control of the inferior mesenteric
artery and identication and protection of the autonomic nerve supply to the genitourinary system. e splenic exure is mobilized, and
the colon is divided just proximal to the start of the cavernous hemangioma. is division is easily determined because large subserosal
serpentine vessels are present along the cavernous hemangioma. e
involved colon is rigid, and the mesentery is thickened. e pelvis is
entered at the level of the sacral promontory anterior to the presacral
fascia. is thick fascia covers the presacral nerves of the hypogastric
plexus. Posterior mobilization of the rectum is carried out sharply
on the fascia propria of the rectum. Care is taken not to enter the
rectal mesentery. Mobilization and division of the lateral ligaments
are performed sharply down to the level of the levator muscles. e
anterior dissection is performed on the rectal side of Denonvilliers
fascia, thus preventing injury to the autonomic nerves. Dissecting in
the correct plane ensures minimal blood loss and a low incidence
of urinary and sexual dysfunction. If a low anterior proctosigmoidectomy is performed, a stapled colorectal anastomosis via the transanal approach is easiest. If the lesion involves the lower rectum, a
modication of the Parks coloanal pull-through procedure can be
performed. e distal mucosal proctectomy is performed transanally.
FIGURE 65-4 A computed tomographic scan illustrates transmural
thickening of the rectal wall and mesorectum and the close adherence
of the lesions to the posterior wall of the bladder and sacrum.
FIGURE 65-5 An angiogram of the inferior mesentery illustrates the
abnormal vascular pattern of the rectosigmoid.
FIGURE 65-6 An angiogram of the inferior mesenteric artery in a
3-year-old boy with cavernous hemangioma of the rectum. Note the
abnormal vasculature caused by these lesions.
NoNepithelial ColoreCtal tumors326
Aer submucosal inltration of a local anesthetic with epinephrine
solution, the mucosal stripping is begun 0.5 cm proximal to the dentate line. e remaining muscular cu is approximately 2 to 3 cm
in length. e descending colon is brought down to the anus, and
the coloanal anastomosis is hand sewn. A proximal loop ileostomy is
performed in the right lower quadrant. e loop ileostomy is closed 8
to 12 weeks postoperatively.
Sphincter-saving procedures have been criticized because of
recurrent bleeding. None of the ve patients in our series has had
recurrent bleeding. We could not have prevented the recurrence
of the hemangioma in the young boy with an abdominoperineal
resection. In the Saint Mark Hospital experience, minor recurrent
bleeding occurred in two patients, and no therapy was required. We
therefore continue to advocate sphincter-saving procedures rather
than abdominoperineal resection.
LEIOMYOMA AND LEIOMYOSARCOMA
Leiomyomas and leiomyosarcomas occur throughout the gastrointestinal tract. Approximately 50% of smooth muscle tumors of the
colon and rectum are malignant. e overall incidence of leiomyosarcomas is 0.1% or less of all rectal malignancies. Smooth muscle
tumors arise from the muscularis mucosae, the muscularis propria,
or the smooth muscle of blood vessel walls. e median age at
presentation is 53 years, with a higher incidence in women. ese
tumors range in size from a few millimeters to 15 cm. Presenting
symptoms are bleeding, constipation, or a sense of fullness in the
rectum. Upon palpation these lesions are smooth, rm, submucosal
tumors. ey can be sessile or pedunculated. Approximately 86%
of all smooth muscle tumors are within reach of a digital rectal
examination.
Characteristic Features
e diagnostic and therapeutic approaches to these lesions combine
both clinical and pathologic ndings. e gross specimen is rm,
with a yellow-white to reddish tan appearance on the cut surface.
Size larger than 2.0 cm and ulceration of the mucosa suggest malignancy. e important microscopic feature is the number of mitoses
per high-power eld, and here the use of the Broder classication is
helpful (Table 65-2). Sarcomas usually metastasize by hematogenous
spread, but local invasion and recurrence are common. Lymph node
metastasis is rare. e cause of death is usually lung or liver metastasis. Preoperative evaluation of a patient with an established leiomyosarcoma includes a CT scan, a chest radiograph, and bone scans. e
TABLE 65-2 : Broder Classification Applied to
Leiomyosarcoma
Grade Description
I A greater abundance of cells is seen in leiomyosar-
coma than in leiomyoma, and a slight increase
in mitotic activity is noted. Individual cells lack
pleomorphism and anaplasia.
II Mitoses are found in one of ve high-power elds.
Nuclei maintain an elongated form, but the nuclear
cytoplasmic ratio is greater than normal.
III Abundant mitotic gures, one to two per high-power
eld, are observed. Pleomorphic cells are present.
IV A high degree of pleomorphism, cellularity, and
mitoses.
5-year mortality rate ranges from 15% to 40%, although few cases
have been reported.
Surgery
A lesion that is 3 cm or less from the dentate line is suitable for transanal excision. While the lesion is being removed, a small margin of
normal tissue should be removed with it. For lesions that are inaccessible transanally, excision by the posterior trans-sphincteric approach
(Mason) has been proposed as an alternative. is operation requires
familiarity with the anatomy of the area. Disagreement has been
expressed in the literature with regard to the overall complication rate
from this surgical technique, with complications such as stula, sepsis,
and incontinence. e principles of the operation are to isolate and
mark the muscle layers as they are dissected to maintain meticulous
homeostasis and to provide adequate local drainage. If a surgeon is not
familiar with this technique, it may be better to refer the patient to a
surgeon with experience or utilize a low anterior resection. Choice of
the transanal or posterior trans-sphincteric approach to these lesions
assumes that these lesions are benign. If the lesion is histologically
malignant, a radical excision is indicated. e surgical conduct of the
operation is important to consider because malignant lesions recur
both locally and via the blood. e use of high vascular ligation and
wide pelvic dissection is essential. If an abdominoperineal resection is
being performed, the perineal dissection is very wide, from the coccyx
to the ischiorectal tuberosities. e place of adjuvant therapy with this
patient population is beyond the scope of this chapter.
PRIMARY LYMPHOMA OF THE COLON AND RECTUM
Primary lymphoma of the gastrointestinal tract is the most common extranodal site of non-Hodgkin lymphoma. e most common
location in the gastrointestinal tract is the stomach, followed by the
small bowel and then the colon and rectum. e colon and rectum
account for about 10% to 20% of all gastrointestinal lymphomas. A
recent review of primary lymphoma of the colon listed the incidence
as 0.2% to 1.2% of colonic neoplasms. e average age of onset is
50 years, with a 2:1 ratio of male to female. e cecum (70%) and
rectum (11%) are the most common sites. Presenting symptoms are
abdominal pain (100%), weight loss (100%), change in bowel habits
(75%), a painful, palpable abdominal mass (80%), hematochezia or
melena (10% to 30%), and obstruction (20% to 25%). Primary gastrointestinal lymphomas were originally dened by Dawson and consist
of ve components (Box 65-1). Today the Mussho Modications to
Ann Arbor Staging System for Extranodal Lymphoma are used. Primary treatment is not surgical, although surgery may be necessary
for making the diagnosis or treating the complications.
e World Health Organization divides gastrointestinal lymphomas into six types (Box 65-2). e most common type in the colon
is diuse large B-cell lymphoma (60%), followed by a lymphoma of
mucosa-associated lymphoid tissue (15%) and Burkitt lymphoma
(15%). e use of chemotherapy and radiation therapy is beyond
BOX 65-1: Primary Gastrointestinal Lymphomas Identified
by Dawson
Components
No palpable supercial lymph nodes at presentation
No enlarged mediastinal lymph nodes on a chest radiograph
Normal range for white blood cell count, including total and
dierential
At surgery, only regional lymph nodes are involved
e liver and spleen are without disease
COLON 327
BOX 65-2: World Health Organization Criteria for
Gastrointestinal Lymphomas
Diuse large cell
Extranodal marginal zone lymphoma (mucosa-associated
lymphoid tissue)
Burkitt
Peripheral T cell
Mantle
Follicular
the scope of this chapter. e incidence of anorectal lymphoma is
higher in association with acquired immune deciency syndrome.
ese lymphomas are undierentiated or large cell type with a B-cell
phenotype, and they tend to invade the perianal skin and ischiorectal areas. Patients present with severe anal pain and hematochezia.
e perineum is very hard and gritty to touch and appears severely
infected. However, it does not respond to antibiotics, and a biopsy
of the area provides the diagnosis. Recently, several cases of primary
lymphoma of the colon presenting as ulcerative colitis or Crohn colitis have been reported. No data support the theory of lymphoma
associated with inammatory bowel disease. ese cases were probably atypical colitis that was unresponsive to standard therapy, and in
retrospect the biopsy interpretation may have been incorrect.
SUMMARY
Nonepithelial lesions of the colon and rectum are rare, but their signs
and symptoms are similar to those of the more common epithelial
lesions. ey form an important part of the dierential diagnosis of
atypical colorectal masses, and an understanding of their pathophysiology and surgical therapy is important. ey are primarily diagnosed
when the surgeon has a high index of suspicion and has taken a thorough history of the patient. e only advances in the management of
cavernous hemangioma of the colon and rectum has been the use of a
minimally invasive approach to their excision and the addition of the
colon J pouch as a reservoir in the ultra-low anastomosis.
S u g g e S t e d R e a d i n g
Borum ML. Cavernous colorectal hemangioma: a rare cause of lower
gastrointestinal bleeding and a review of the literature. Dig Dis Sci.
1997;42(12):2468–2470.
Byun JY, Kim AY, Cho KS, etal. Radiological features of leiomyomatous tu-
mors of the colon and rectum. J Comp Assist Tomog. 2000;24(3):407–412.
Fan CW, Changchien CR, Wang JY, etal. Primary colorectal lymphoma. Dis
Colon Rectum. 2000;43(9):1277–1282.
Friesen R, Moyana TN, Murray RB, etal. Colorectal leiomyosarcomas: a patho-
biologic study with long-term follow-up. Can J Surg. 1992;35(5):505–508.
Hara AK, Johnson CD, Reed JE. Colorectal lesions: evaluation with CT colog-
raphy. Radiographics. 1997;17(5):1157–1167.
Leal RF, Ayrizono Mde L, Silva PV, etal. Laparoscopic-assisted bowel resec-
tion with construction of a colonic reservoir for cavernous hemangioma
of the rectum: report of two cases. Tech Coloproctol. 2011;15(2):205–207.
Miettinen M, Sarlomo-Rikala M, Sobin LH. Mesenchymal tumors of mus-
cularis mucosae that should be separated from gastrointestinal stromal
tumors—a clinicopathologic and immunohistochemical study of eightyeight cases. Mod Pathol. 2001;14(10):950–956.
Singland JD, Penna C, Pare R. Colorectal cavernous hemangiomatosis
treated by total coloproctectomy and ileo-anal anastomosis. Ann Chir.
1997;51(4):382–384.
Stanojevic GZ, Nestorovic MD, Brankovic BR, etal. Primary colorectal lym-
phoma: an overview. World J Gastrointest Oncol. 2011;3(1):14–18.
Times M. Colorectal lymphoma. Clin Colon Rectal Surg. 2011;24(3):135–141.
Wang HT, Gao XH, Fu CG, et al. Diagnosis and treatment of diuse cav-
ernous hemangioma of the rectum: report of 17 cases. World J Surg.
2010;34(10):2477–2486.
M
C I
Vikram Reddy and Walter Longo
INTRODUCTION
Intestinal ischemia produces a spectrum of diseases aecting the gastrointestinal tract. ese syndromes, which can be acute or chronic,
can aect the upper abdominal viscera, as well as the small intestine,
colon, and rectum. ey account for signicant morbidity and mortality and continue to be the subject of clinical and laboratory investigation. e most common form of intestinal ischemia is ischemic
colitis, accounting for 50% to 60% of all cases, with an incidence of
4.5 to 44 cases per 100,000 patients per year. e pathophysiologic
changes associated with ischemic disease of the colon are related to
numerous factors. In certain circumstances, these factors are known
and may be corrected, but more oen they are unknown, and treatment is based on symptoms.
Cases of colonic gangrene were rst described in the late nineteenth and early twentieth centuries, but it was not until the 1960s
that the pathophysiology of ischemic colitis was appreciated. In 1963,
Boley described noniatrogenic, spontaneous colon ischemia in ve
patients. In 1966, Martson coined the term colonic ischemia, or isch-
emic colitis, when he described 16 cases of spontaneous colonic ischemia. Usually no major vessel occlusion occurs, and oen the original
insult precipitating the ischemic event cannot be established. Many
advances in the diagnosis and treatment of patients with colonic ischemia have been made since it was originally described by Boley and
colleagues, and it is clear that the outcome depends on numerous factors, including the severity, extent, and rapidity of the ischemic insult,
as well as the therapy provided. Increased awareness of this disease
and knowledge regarding appropriate treatment are fundamental for
its successful management.
in persons who use laxatives), hypertension, diabetes, and renal failure. Trauma, thrombosis, or immobilization of the mesenteric arteries can cause occlusion of the blood supply to the colon, although
such instances are rare. Several medications have been implicated in
the occurrence of colonic ischemia. Colonic obstruction related to
tumor, adhesions, diverticular disease, volvulus, or fecal impaction
also may be responsible. In most cases, however, no precipitating
cause or event can be identied.
Colonic ischemia in younger patients is usually related to medications and drugs, intensive exertion, vasculitis, and sickle cell disease.
For unknown reasons, the right colon is frequently involved.
Several factors predispose the colon to ischemia. e splanchnic
circulation receives 10% to 35% of the cardiac output, but the colon
has less blood ow per 100 g of tissue than does any other part of the
gastrointestinal tract. e colon also frequently relies on a collateral
arterial circulation. Another factor predisposing the colon to ischemic
insult is the decrease in blood ow that accompanies the functional
motor activity of the colon. During hypotension, the colon does not
autoregulate well compared with the remainder of the gastrointestinal
tract, and oxygen supply quickly reaches a critically low level, resulting in ischemia. e initial insult to the colon is usually seen in the
mucosa and subsequently extends to the submucosa and muscularis.
is mucosal change is most evident at the antimesenteric border of
the colon. With impairment of the blood ow to the colon, mucosal
injury will develop within 20 to 60 minutes, whereas transmural infarction can take up to 8 to 16 hours to develop. Unfortunately, re-establishment of blood ow is associated with reperfusion injury because of
the formation of reactive oxygen species, which cause peroxidation of
ETIOLOGY AND PATHOGENESIS
Causes of colonic ischemia (Table 66-1) can be classied as either
occlusive or nonocclusive. Frequently, a cause is not easily identied.
Spontaneous episodes of ischemic colitis are by far the most common form of the disease and generally are viewed as localized forms
of nonocclusive ischemia. Colonic blood ow is decreased by a variety of local and systemic physical and biochemical factors, through
intensive vasoconstriction and arteriovenous shunting within the
mesenteric circulation and bowel wall. Furthermore, obstruction
or diuse vasospasm involving the major arterial supply of the large
intestine can result in severe ischemia to extensive regions of the
colon or rectum.
Patients with ischemic colitis tend to have several risk factors for
vascular disease, including age greater than 65 years, cardiac arrhythmias, and thrombophilia. Antiphospholipid antibodies and factor V
Leiden mutations are more frequently noted in patients with ischemic
colitis. Increased risk of colonic ischemia is also seen in patients with
irritable bowel syndrome (threefold higher), chronic obstructive pulmonary disease (two- to fourfold higher), constipation (even higher
328
CLASSIFICATION
Clinically, the two principal forms of ischemic colitis noted are a gangrenous and a nongangrenous type. Nongangrenous ischemia can be
a transient reversible form or a chronic form (Fig. 66-1). e severity
of the ischemia determines the depth of the tissue damage, with transmural necrosis noted in gangrenous colitis and mucosal or submucosal
involvement noted in the nongangrenous form, which accounts for
80% to 85% of cases. In the 15% to 20% of cases of gangrenous colitis,
surgical resection of the involved colonic segment is required. Gangrenous ischemic colitis is associated with a mortality of up to 50%.
e transient reversible form of nongangrenous ischemic colitis is
characterized by edema, submucosal hemorrhage, and partial mucosal necrosis. A complete structural and functional recovery usually
occurs within 1 to 2 weeks with no long-term sequelae. If the ischemia extends to the muscularis propria, the damaged muscularis is
replaced by brous tissue over a period of weeks to months, sometimes resulting in a stricture. ese strictures may be symptomatic.
Chronic damage in the form of persistent segmental colitis and stricturing occurs in 20% to 25% and 10% to 15% of patients, respectively.
TABLE 66-1: Causes of Colonic Ischemia
Occlusive Nonocclusive
Arterial Hypoperfusion
rombosis
Embolic Cardiac
Cholesterol
Small vessel disease Atherosclerosis
Diabetes
Radiation
Amyloidosis
Rheumatoid arthritis
Vasculitis
Systemic Lupus
Erythematosus
Polyarteritis Nodosa
Allergic granulomatosis
Scleroderma
Behcets syndrome
Takayasu’s arteritis
romboangitis obliterans
Buerger’s disease
Trauma
Iatrogenic
Drugs
COLON 329
Hypovolemia
Anaphylaxis
Shock
Aortic balloon pump
Hemodialysis
Digitalis
Diuretics
Non-steroidal antiinammatory
drugs
Estrogen
Danazol
Gold
Sumatriptan
Alosetron
Paclitaxel and carboplatin
Tegaserod
Neuroleptics
Catecholamines
Interferon-ribavirin
Laxatives
Anti-motility agents
Surgical
Cardiopulmonary bypass
Long distance running
Aortoiliac reconstruction
Endoscopy
Colectomy + IMA ligation
Venous Obstruction
Hypercoagulable state
Colonic Obstruction
Sickle cell disease
Portal Hypertension
Pancreatitis
Ischemic colitis may involve any portion of the colon and rectum,
although the splenic exure, descending colon, and sigmoid are most
commonly aected, accounting for 75% of all cases. Certain causes
have a propensity to aect specic areas of the bowel. Ischemia resulting from systemic low-ow states usually involves the right colon,
most commonly its retroperitoneal surface. Localized, nonocclusive
ischemia classically involves watershed areas of the colon such as the
splenic exure (Grith’s point) and the junction of the sigmoid and
rectum (Sudek’s point). e right colon is involved in approximately
10% of the cases, and right colon ischemia may be a manifestation
of midgut ischemia resulting from an embolus or thrombus in the
superior mesenteric artery, because the midgut includes this part of
the colon. Ischemic proctosigmoiditis is a rare event (discussed in a
subsequent section).
Nongangrenous
(80%–85%)
Transient,
reversible
Volvulus
Diverticular disease
Colon cancer
Constipation
Pseudo-obstruction
Ischemic colitis
Gangrenous
(15%–20%)
Chronic,
nonreversible
CLINICAL PRESENTATION
Ischemic colitis presents with acute onset of abdominal pain and
cramping that oen is localized to the lower abdomen and frequently to the le side. An acute urge to defecate as a result of
Chronic
segmental
colitis
(20%–25%)
FIGURE 66-1 Classification of ischemic colitis.
Stricture
(10%–15%)
ManageMent of ColoniC isCheMia330
reactive muscle spasm oen accompanies the pain. Hematochezia
may develop within 24 hours; blood loss is usually mild, but “red
currant jelly” stools may be present. Occasionally patients present
with painless diarrhea with or without hematochezia. Other symptoms include diarrhea (68%), abdominal distention (63%), and nausea/vomiting (38%).
Abdominal examination is signicant for mild tenderness that
usually corresponds to the site of ischemia, along with mild distention. A low-grade fever may accompany the pain. Rectal examination
reveals either fresh blood or heme-positive stool. Moderate leukocytosis with a le shi is oen seen. Peritoneal signs such as rebound
and guarding are more suggestive of late transmural ischemia, and
these patients usually have other signs of systemic inammatory
response syndrome. Once patients with full-thickness gangrene
experience a perforation through the dead bowel, signs and symptoms of a catastrophic abdominal event occur, including sepsis and
shock.
Ischemic colitis is not limited to elderly persons. Colonic ischemia
may aect younger people, for whom the causes include vasculitis,
medication-induced reactions, coagulopathies, sickle cell disease,
long-distance running, and cocaine abuse. Because they have fewer
comorbidities, these patients usually tolerate both surgery and ischemia well.
Chronic ischemic colitis can present with distention and obstipation as a result of ischemic strictures in the aected segment of
intestine.
DIAGNOSIS
Ischemic colitis is oen suggested by the history and physical ndings
and supported by the presence of fever and leukocytosis, but because
of the broad dierential diagnosis and the diculty in identifying a
cause, the denitive diagnosis is oen delayed.
Routine laboratory studies are nonspecic, and leukocytosis is the
only common nding. Elevated lactate and metabolic acidosis levels
are late signs and may only be present in cases of severe ischemia or
necrosis. Serum levels of stereoisomer d-lactate (produced only by
bacteria in the colon) have shown promise as a sensitive marker of
colonic ischemia.
Plain radiographs can demonstrate “thumb printing” as a result
of edema of the colonic mucosa. Pneumoperitoneum, pneumatosis
intestinalis, or portal venous gas signify advanced ischemia or infarction and the need for an immediate exploratory laparotomy. Contrast
enemas have largely been supplanted by endoscopy, but they still have
a role in the identication of strictures. Angiography is indicated
when the diagnosis of acute mesenteric ischemia is being contemplated or when the initial colonoscopic examination is nonrevealing
or demonstrates isolated right-sided colonic ischemia. Computed
tomography (CT) is helpful in narrowing down the broad dierential
associated with abdominal pain, but with ischemic colitis it demonstrates nonspecic ndings, such as a thickened bowel wall, perico-
of mesenteric ischemia such as emboli or thrombus occasionally can
be seen. CT ndings do not correlate with or predict the development
of bowel infarction.
In patients in whom colonic ischemia is suspected, colonoscopy is indicated, as long as peritonitis is not present and findings
of abdominal radiographs are normal. Colonoscopy is preferred
because it is most sensitive tool for diagnosing mucosal abnormalities and enables biopsy specimens to be obtained. Within
48 hours of the onset of ischemia, the mucosa appears pale and
edematous, with areas of petechiae and small ulcers. Other early
signs of ischemia, such as a single linear ulcer, can be noted on the
antimesenteric border of the affected colon. Hemorrhagic nodules
may bleed into the submucosa and may cause the “thumbprints”
or “pseudo tumors” seen on barium studies, which indicate more
advanced ischemia. A segmental distribution of these findings,
with or without ulceration, strongly suggests colonic ischemia.
After the initial 48 hours, sloughing of mucosa and ulcerations are
noted. Where the luminal surface is gray-green or black, transmural infarction of the bowel wall is likely. Colonoscopy is performed
with special care. Distention of the bowel with room air to pressures greater than 30 mm Hg further diminishes colonic blood
flow and actually may increase colonic ischemia. Use of carbon
dioxide insufflation is a better option because of its rapid absorption and vasodilatory effect. Chronically ischemic colon can be
more fragile than normal and more prone to perforation, especially with repeated endoscopy.
Histologically, biopsy specimens show loss of mucin and surface
epithelial cells along with degeneration of normal crypt architecture.
e extent of the derangement depends on the degree of ischemic
changes. Vascular congestion, damage in the supercial mucosa,
and the presence of acute and chronic inammatory cells are more
common. e presence of ghost cells, which is suggestive of mucosal
infarction, is pathognomonic for ischemia. e precise endoscopic
and histologic picture of ischemic colitis depends on the rate of the
ischemic insult and the stage in the natural history of the disease at
which the diagnostic studies are performed.
MANAGEMENT
e management of colonic ischemia depends on its cause and severity (Fig. 66-2). If the ischemia is mild with no evidence of gangrene
or perforation, no active treatment is required. Very mild cases can
be managed on an outpatient basis. Generally, if the patient has
abdominal pain, bowel rest is initiated, parenteral uids are given,
and empiric broad-spectrum antibiotics cover aerobic and anaerobic bacteria translocation. Cardiac output and oxygenation should be
optimized. Any inciting cause should be managed.
In most cases of colonic ischemia, signs and symptoms of the illness subside within 24 to 48 hours, and submucosal and intramural
hemorrhages are resorbed. Clinical and radiologic resolution is virtually complete within 1 to 2 weeks. More severe ischemia with necrosis of the mucosa and submucosa produces ulceration, inammation,
and possibly chronic segmental ulcerating colitis or strictures. An
initial attempt can be made to manage patients with chronic segmental colitis symptomatically.
In patients who show no clinical improvement in 24 to 48 hours,
repeat endoscopy or imaging is warranted to assess disease progression. In the event of pneumoperitoneum, worsening clinical symptoms, uncontrolled bleeding, or failure of conservative management,
resection will be required because of increasing concern for colonic
infarction. Intraoperatively, assessment of colonic viability may be
achieved via colonoscopy, evaluation of the antimesenteric serosal
surface with use of handheld, continuous-wave Doppler, tonometric measurement of intramural pH, pulse oximetry of transcolonic
oxygen saturation, or use of intravenous uorescein. If creation of
an anastomosis is contemplated, bleeding from the resection margins
must be vigorous. Persistent concerns about remaining or ongoing
ischemia mandate deferral of an anastomosis and a planned secondlook laparotomy, because additional resection is required in 25%
of these patients. It has been suggested that a primary anastomosis
should not be attempted in patients with colonic gangrene but that a
stoma and mucus stula should be performed instead. However, an
anastomosis can be created in a stable patient with uncomplicated
right colon ischemia.
Patients with colonic strictures due to ischemic colitis can be
treated with elective resection if no evidence of acute large bowel
obstruction is found. Management usually involves resection with
creation of a primary anastomosis. If the strictures are relatively
short, endoscopic dilation or stenting are alternatives to surgical
intervention.