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50% of patients with AMs. All patients must be evaluated at birt h to rule out any of these
defects, and abdominopelvic ultrasound is the most valuable screening test. Urologic
evaluation should be carried out prior to colostomy so that the surgeon can adequately
deal with the urologic problem at the time of the colostomy. The surgeon must also be
prepared to perform a urologic diversion in case one is needed.
Later studies, such as lumbosacral spine X-ray to obtain the sacral ratio and rule out
dysraphism are not urgent, but they are important for completing the diagnostic
approach. Likewise, extension studies, such as cystography, echocardiography, or magnetic resonance, can be carried out if they are needed for the evaluation of other associated defects.
Distal colostogram should be performed to define the malformation and establish a surgical plan. In centers such as ours, the pediatric surgeon responsible for the patient directly
carries out that study, given that it guides therapeutic conduct. Water-soluble contrast
medium, diluted with 50% water, is recommended. An initialnoncontrasted X-ray is carried
out, in which anteroposterior and lateral views of the lumbosacral spine are generally
utilized to observe and rule out dysraphism and obtain the sacral ratio. Contrast medium
is then introduced to appropriately outline the anorectal abnormalities (Fig. 14.3).
FIG. 14.3 Distal colostogram showing the presence of a recto-urethral-bulbar fistula.
182 ANORECTAL DISORDERS
14.4 Treatment
14.4.1 Medical Approach
After their diagnostic evaluation, all patients with AMs should preferably be admitted to a
neonatal area, kept in a fasting state with an orogastric tube, kept adequately hydrated
(through intravenous solutions), and given antibiotics to prevent an associated septic process. The customary regimens include ampicillin and amikacin. With the possibility of
immediate surgical treatment in mind, supplementary vitamin K administration and
blood type and Rh determination are recommended.
14.4.2 Surgical Approach
AM repair requires a meticulous and delicate technique performed by a surgeon with
experience in the management of these defects. It is important to optimize times and
make early decisions in accordance with the diagnostic test findings and the type of
AM detected. An ectopic anal orifice can be located at the midline of the perineum or
the scrotum. Meconium at the perineal raphe line is suggestive of an AM that does not
require intestinal diversion and is generally immediately resolved in one-stage surgery
through anoplasty. It can occasionally present with a long strictured fistula that requires
expanding the initial approach and considering colostomy.
Anoplasty is a relatively simple surgery in which an anal membrane (
Fig. 14.4) covering
the orifice is generally removed and the anal mucosa is attached to the skin through simple separate sutures of 5-0 polyglycolic acid, utilizing quadrants to guide their application.
The decision to carry out a colostomy should be made after a meticulous physical
examination and, if necessary, a radiologic invertogram study 18 h after birth. When performing a colostomy, the following considerations sho uld be observed in all patients: the
right lower quadrant should be the first option as the diversion site, unless there is a specific contraindication for that location. The distal and proximal segme nts of the descending colon should be identified at the time of abdominal cavity examination, preventing
stoma inversion and also ensuring a sufficiently long distal segment so that the PSARP
can be performed in a second surgery with no length restriction. Diversion should take
place at the fixed portion of the descending colon, to prevent prolapse of the stomas. If
that is not possible, then it will be necessary to fix the bowel segment to the abdominal
wall through simple absorbable sutures. The openings of the stomas should be far enough
apart (
Fig. 14.5) to prevent the distal flow of intestinal content and thus reduce the pos-
sibility of urinary tract infection.
13
After the performance of intestinal diversion, the patient should be re-evaluated
through distal colostogram (
Fig. 14.6) to redefine the type of AM.
The definitive surgical procedure for correcting these defects (Fig. 14.6) is PSARP, which
was first described nearly four decades ago and which over time has been shown to be the
best surgical option.
14
In recent years, a mixed approach with laparoscopy has been incor-
porated for specific AMs, such as rectal fistula to the bladder neck, as well as new surgical
Chapter 14 • Anorectal Malformations 183
FIG. 14.4 Anoplasty for the treatment of anal membrane. Anorectal malformation: bucket handle anal membrane
variant.
FIG. 14.5 Double-barrel colostomy. Double-barrel colostomy placed sufficiently apart.
184 ANORECTAL DISORDERS
techniques, but PSARP is still considered to be the most adequate technique for resolving
those problems.
15
A detailed description of this surgical technique does not fall within the
scope of the present review, but there are classic publications in the medical literature on
the subject (
Fig. 14.7).
16
14.5 Follow-Up
Careful, regular follow-up is necessary in these patients to accurately reassess their prognosis and avoid problems that can dram atically impact the ultimate functional results.
Follow-up should be carried out in patients with AM for most of their lives, given that
many conditions can present, such as constipation, pseudo-incontine nce and fecal
FIG. 14.6 Distal colostogram after colostomy. Anorectal malformation: blind-ending rectal segment variant
with no fistula in a patient with trisomy 21.
Chapter 14 • Anorectal Malformations 185
incontinence, urinary incontinence, urologic disorders, different gynecologic disorders,
neurologic disorders in patients with tethered spinal cord syndrome, etc.
9,17,18
References
1. Wang C, Li L, Cheng W. Anorectal malformation: the etiological factors. Pediatr Surg Int. 2015;
31(9):795–804.
2. Herman RS, Teitelbaum DH. Anorectal malformations. Clin Perinatol. 2012;39:403–422.
3. Bischoff A, Levitt MA, Pen˜a A. Update on the management of anorectal malformations. Pediatr Surg
Int. 2013;29:899–904.
4. Georgeson KE, Inge TH, Albanese CT. Laparoscopically assisted anorectal pull-through for high imper-
forate anus—a new technique. J Pediatr Surg. 2000;35(6):927–931.
5. Morandi A, Ure B, Leva E, Lacher M. Survey on the management of anorectal malformations (ARM) in
European pediatric surgical centers of excellence. Pediatr Surg Int. 2015;31:543–550.
6. Santulli TV, Kiesewetter WB, Bill Jr AH. Anorectal anomalies: a suggested international classification.
J Pediatr Surg. 1970;5(3):281–287.
7. Wood RJ, Levitt MA. Anorectal malformations. Clin Colon Rectal Surg. 2018;31:61–70.
8. Gangopadhyay AN, Pandey V. Anorectal malformations. J Indian Assoc Pediatr Surg. 2015;20(1):10–15.
9. Grano C, Bucci S, Aminoff D, Lucidi F, Violani C. Quality of life in children and adolescents with anor-
ectal malformation. Pediatr Surg Int. 2013;29:925–930.
10. Hofmann AD, Puri P. Association of Hirschsprung’s disease and anorectal malformation: a systematic
review. Pediatr Surg Int. 2013;29:913–917.
FIG. 14.7 Example of anorectal malformations. (A) Cloacal malformation variant. (B) Vestibular fistula variant,
the most common defect in girls. The presence of the hymen is important; if it is absent then the malformation
is most likely a cloacal variant of AM.
186 ANORECTAL DISORDERS
11. Lee JK, Towbin AJ. Currarino syndrome and the effect of a large anterior sacral meningocele on distal
colostogram in an anorectal malformation. J Radiol Case Rep. 2016 June 30;10(6):16–21.
12. Totonelli G, Catania VD, Morini F, et al. VACTERL association in anorectal malformation: effect on the
outcome. Pediatr Surg Int. 2015;31:805–808.
13. Pen˜a A, Migotto-Krieger M, Levitt MA. Colostomy in anorectal malformations a procedure with
serious but preventable complications. J Pediatr Surg. 2006;41:748–756.
14. Pena A, DeVries PA. Posterior sagittal anorectoplasty: important technical considerations and new
applications. J Pediatr Surg. 1982;17:796–811.
15. Willital GH. Endosurgical intrapuborectal reconstruction of high anorectal anomalies. Pediatr
Endosurg Innov Tech. 1998;2:5–11.
16. Pena A. In: Ziegler, Azizkhan, Gauderer, Weber, eds. Anorectal Malformations: Operative Pediatric Sur-
gery. Boston, MA: Appleton & Lange; 2005.
17. Grano C, Bucci S, Aminoff D, Lucidi F, Violani C. Does mothers’ perception of social support mediate
the relationship between fecal incontinence and quality of life of the child? Pediatr Surg Int.
2013;29:919–923.
18. Gribbin E, Croaker D. Long-term follow-up of paediatric anorectal anomalies and the role and efficacy
of parent support groups for such conditions. Pediatr Surg Int. 2013;29:931–936.
Chapter 14 • Anorectal Malformations 187
15
Anal Tumors
Andreia Albuquerque
FAC U L T Y Of M E D I C IN E O F TH E U N I V E RS I T Y O F P O R T O, P O R TO , P O R TU G A L HO ME R T O N ANAL
NE O P L A SI A S E RV I C E ( H A N S ), H O M ER T O N U N I V E R SI T Y HOS P I T A L, L O N DO N , UN I T E D K I N G D OM
15.1 Introduction
Anal tumors comprise a vast group of histologically different lesions. Anal squamous cell
carcinoma (SCC) is the most common of the anal cancers
1, 2
and is largely associated with
anal human papillomavirus (HPV) infection.
3
Anal squamous intraepithelial lesions, or
anal intraepithelial neoplasia (AIN), is the recognized anal precancerous lesion, with a
higher prevalence in high-risk groups for HPV infection.
4–7
The incidence of anal SCC
has been rising
1
and this is expected to continue,8so target prevention strategies are
needed. Altogether other cancers comprise 15%–20% of the anal lesions,
9,10
and many
of these are anal adenocarcinoma (ADC). Besides SCC and ADC, other cancers are
extremely rare and most of the published literature comprises case reports.
In this chapter several anal tumors will be described in more detail, namely anal squamous intraepithelial lesions, anal SCC, anal Buschke Loewenstein tumor, anal ADC, extramammary Paget disease (EMPD), anal melanoma, anal neuroendocrine neoplasm, anal
lymphoma, anal mesenchymal tumor, anal basal cell carcinoma, and anal metastasis.
15.2 Anal Squamous Intraepithelial Lesions
Anal squamous intraepithelial lesions or AIN are considered anal SCC precancerous
lesions and are related to anal HPV infection. In 2012, the Lower Anogenital Squamous
Terminology
11
was published recommending that these lesions be classified as either
low-grade squam ous intraepithelial lesions (LSIL) or high-grade squamous intraepithelial
lesions (HSIL) in all anogenital sites. This classification replaced the former three-tiered
system that included AIN1 as low-grade lesions and AIN2 and AIN3 as high-grade lesions.
Anal squamous intraepithelial lesion is the most current accepted term,
11
in preference to
“anal intraepithelial neoplasia,” “dysplasia,” “carcinoma in situ” (for high-grade lesions),
or “Bowen’s disease” (for perianal lesions). In cervical disease, 31% of untreated cer vical
intraepithelial neoplasia (CIN3) are expected to progress to cervical cancer in a 30-year
period.
12
The risk of anal HSIL progressing to anal SCC is less well established, but it
was estimated to be around 1 in 377 HIV-positive patients per year, in the highly active
antiretroviral therapy (HAART) era.
4
Anorectal Disorders. https://doi.org/10.1016/B978-0-12-815346-8.00015-1
© 2019 Elsevier Inc. All rights reserved.
189
There are some groups that are identified as having a higher risk of these lesions,
namely men who have sex with men (MSM), HIV-infected patients,
4
women with a history
of lower genital tract neoplasia,
5
and solid organ transplant patients.
6, 7
A systematic
review and meta-analysis revealed that in HIV-positive MSM the prevalence of anal HSIL
was 29.1% and in HIV-negative MSM it was 21.5%.
4
In kidney-transplant recipients the
prevalence of anal squamous intraepithelial lesions was shown to be 20%, with a 5% prevalence of anal HSIL.
6
Cervical and anal carcinogenesis are thought to be similar processes. They are caused
by the same virus, have the same anatomic susceptible area (squamocolumnar epithelium), and demonstrate the same precancerous lesions.
13
Due to these similarities, an anal
screening strategy based on cytology, with referral of those with abnormalities to highresolution anoscopy (HRA), has been suggested for high-risk groups.
14, 15
HRA is a similar
technique to colposcopy in the cervix, which allows the visualization of the anal and
perianal area under magnificatio n. An anoscope is inserted and a colposcope is used to
examine the squamocolumnar junction, the anal canal, and perianus. No bowel preparation is necessary. A topical application of 5% acetic acid (
Fig. 15.1) and Lugol’s iodine will
help reveal suspicious HSIL, that should be biopsied.
16
This technique can diagnosis
unsuspicious lesions undetectable by the naked eye. The features of these magnified
FIG. 15.1 HIV-positive woman with a previous history of vulvar neoplasia, with large and diffuse acetic acid-induced
white lesions in the perianus. Multiple biopsies confirmed a high-grade squamous intraepithelial lesion diagnosis.
190 ANORECTAL DISORDERS
lesions can be highly suggestive of the histological type. HSIL are commonly acetic acidinduced white lesions, with mosaic and punctuation and no Lugol uptake.
There are several issues limiting the introduction of an anal cancer screening program
in some settings. Most importantly there is currently a lack of information from randomized control trials showing a clear benefit in treating anal HSIL to prevent anal cancer. Anal
LSILs are normally not treated and patients are kept under surveillance. One of the major
differences between the cervix and the anus lies in the treatment; areas of cervical HSIL
can be easily treated with excision procedures removing the squamocolumnar transformation zone where most precancerous lesions developed. This is not possible for anal
HSIL, and surgical excision was associated with persistent disease, recurrence, and a
higher morbidity.
17
There is no “gold standard” method for treating anal and/or perianal
HSIL, and several methods were described: infrared coagulation, electrocautery, laser,
photodynamic therapy, radiofrequency, cryotherapy, argon plasma, and topical agents
like imiquimod, 5-fluorouracil (5-FU), cidofovir, and trichloroacetic acid. The high recurrence rates are an important issue.
18
Successful ablation of the lesions can be achieved in
many cases, but the persistence of the anal HPV infection and the remainder of the squamocolumnar epithelium are major factors in this high rate of recurrence.
15.3 Anal SCC
Anal SCC is the most common histological type of anal cancer,
1
corresponding to 74% of
anal cancers.
2
It is considered to be an uncommon malignancy.2The incidence rates have
been increasing in recent years in most countries either in both men and women, or only
in women.
1
An increasing prevalence is also expected for the next decades.8Women are
more frequently affected.
8
Around 90% of anal SCCs can be attributed to HPV,3more commonly HPV 16 and 18.
19
HIV-positive MSM have higher incidence rates, 45.9 per 100,000 men. In HIV-negative
MSM incidence rates are 5.1 per 100,000 men.
4
The improved survival rates of HIVpositive patients that were seen after HAART introduction, contributed to the increased
rate of anal SCC in this population.
4
The anal cancer risk increases with the cumulative
duration of CD4 counts <200 cells per μL.
20
Current smoking has been shown to also
increase the risk of this cancer.
21
Anal sexual intercourse is a well-recognized risk factor
in men,
21
but in women it has not been consistently associated.22Women with a previous
history of genital HSIL or cancer also have a higher risk of developing anal SCC.
23
In a
transplant setting, kidney transplanted patients are the most well-studied group, and
the relative risk is 10 times higher than in nonimmunosuppressed patients.
24
A higher
incidence of anal SCC, with an earlier age of presentation and poorer outcomes in patients
with Crohn’s disease, was also shown.
25
Rectal bleeding, pain, and sensation of an anal mass (Fig. 15.2) are possible presenting
symptoms, although patients can be asymptomatic. According to the National Comprehensive Cancer Network 2017 guidelines
26
on anal carcinoma, a patient’s workup should
include a digital rectal examination, anoscopy, palpation of the inguinal lymph nodes,
Chapter 15 • Anal Tumors 191
chest/abdominal computed tomography (CT) scan, and a pelvic CT scan or magnetic resonance imaging. HIV testing and, in women, a gynecologic examination including cervical
cancer screening should also be done. A positron-emission tomography (PET) scan can be
considered in the evaluation of pelvic nodes.
Chemotherapy with or without radiotherapy is the “gold standard” for treatment. An
exception is anal margin SCC T1N0 well-differentiated cancers, where local excision
can be considered for therapy and is curative if adequate margins are achieved.
26
Abdominoperineal resection can be used in locoregional progressive disease after primary
treatment, and in local recurrences.
26
The patient being male, a node-positive cancer,
and a tumor diameter of >5 cm are associated with worst overall survival.
27
The increase in anal SCC rates can be linked to the increased incidence and persistence
of anal HPV infection, and measures aiming to reduce this, like HPV vaccination, might
help prevent anal SCC.
1
15.4 Anal Buschke-Loewenstein Tumor
This is a rare disease, typically a cauliflower-like tumor, with a large size and local invasion
capability, caused by HPV infection (especially HPV 6 and 11). It most often affects the
glans penis but has also been reported in the scrotum, vulva, perianal region, and bladder.
28
Transformation in anal SCC can occur and recurrence rates are high.28Several
therapeutic approaches were described, depending also on the presence of anal SCC,
including surgery, chemoradiotherapy, laser, and photodynamic therapy.
28
FIG. 15.2 Woman presenting with a 3-cm indurated perianal mass. Biopsies confirmed an anal squamous cell
carcinoma diagnosis.
192 ANORECTAL DISORDERS
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