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512
Fig. 66.1 Algorithm for Recurrent Colon Cancer. LR local recurrence, XRT radiation therapy, IORT introperative
radiation therapy, CRS cytoreductive surgery, HIPEC heated intra-peritoneal chemotherapy
D. Liska and L. Stocchi
abdomen, and pelvis to allow for the detection of any distant metastases. While a full
colonoscopy is essential to assess the prior
anastomosis for recurrence and the residual
colon for any metachronous lesions, the
majority of recurrences are extraluminal and
are therefore not amenable to endoscopic
biopsy. CT or ultrasound-guided biopsies
should be performed to conrm the diagnosis. In cases not amenable to percutaneous
biopsy PET scans are now routinely used to
assist in establishing the diagnosis of recurrent disease (Fig.66.2). When clinical suspicion (due to new symptoms and/or CEA
elevation) is conrmed by cross sectional and
functional imaging, the absence of a tissue
diagnosis should not preclude treatment.
When there is a concern for local invasion of
adjacent organs, bone, nerves, or blood vessels, contrast enhanced MRI should be
employed to assess for tumor resectability
and operative planning.
D. Once the diagnosis of recurrent colon cancer
has been established, the most important
question to answer is if salvage surgery with
curative intent is ultimately possible. This
assessment depends on the local and distant
extent of disease and the overall medical
condition of the patient. Review of the
patient’s medical and treatment history,
imaging, and pathology specimens in the setting of a multidisciplinary disease management team (i.e., tumor board) is essential
when considering all possible treatment
options. Widespread metastatic disease,
extensive invasion into large vessels or
nerves, or major comorbid conditions are
factors that preclude curative intent surgery.
In these cases the focus should shift to control of disease progression with chemotherapy and palliation of symptoms.
E. Patients with a colonic obstruction—in the
setting of recurrent disease that is not amenable to curative resection—present a signicant challenge in selecting the optimal
treatment modality. The possible treatments
include a palliative resection with or without
restoration of intestinal continuity, fecal
diversion with a diverting ostomy, intestinal
by-pass, or endoscopic deployment of a selfexpandable metal stent (SEMS). Especially
in patients with distal obstructions, SEMS
can be an attractive option for palliative
treatment due to the minimal invasiveness of
the procedure. In experienced hands, SEMS
can be deployed with very high technical
and clinical success rates, resulting in rapid
resolution of the obstruction with short hospital stay and minimal recovery. However,
stents are associated with a risk of perforation, migration, and re- obstruction, often
necessitating subsequent procedures or surgeries. Surgical treatment with resection or
fecal diversion provides more durable palliation at the cost of increased peri-operative
morbidity, length of hospital stay, and need
66 Recurrent Colon Cancer
513
Fig. 66.2 Imaging one year following right hemicolectomy for hepatic exure adenocarcinoma: CT with contrast and subsequent PET/CT demonstrating FDG avid
for an ostomy. Palliative treatment decisions
need to be individualized, and should be
based on available resources, estimated
patient life-expectancy, and quality of life
considerations.
F. Medically t patients with resectable disease
are candidates for treatment with curative
intent. The decision to proceed with immediate surgery versus preoperative chemotherapy
or radiotherapy needs to be individualized
based on the location of the local recurrence,
presence of metastases, and previous treatment regimens. Preoperative chemotherapy
should be strongly considered for patients
with LR in the setting of oligometastases to
lymph node recurrence adjacent to the superior mesenteric artery (SMA) and ileocolic anastomosis (ICA)
the lung or liver. Advantages of preoperative
administration of chemotherapy include the
ability to eradicate micrometastatic disease,
to reduce the size of gross disease requiring
resection, and to assess for chemotherapeutic
sensitivity to help guide future treatment
decisions. Potential disadvantages of preoperative chemotherapy include toxicities that
may increase the risk of perioperative morbidity, and the possibility of tumor progression while awaiting surgery. In general,
though, patients with signicant metastatic
disease progression while on preoperative
chemotherapy are unlikely to benet from
radical surgery and can thereby be selected
514
D. Liska and L. Stocchi
for palliative treatments prior to embarking
on morbid, unhelpful surgical procedures.
Recurrent locoregional disease with threatened resection margins warrants consideration for preoperative chemotherapy to
reduce the risk of subsequent local recurrence. The use of combined radiotherapy to
maximize local control is more controversial.
In cases where preoperative external beam
radiotherapy (EBRT) would entail toxicity to
dose-sensitive viscera, or in cases of previous
irradiation, intraoperative radiotherapy
(IORT) can be used to allow precise delivery
of a single large fraction of radiation to high
risk target areas while shielding radiosensitive viscera. While there is evidence supporting the role of IORT in recurrent rectal cancer,
this approach has been less frequently
described in the management of colon
cancer.
G. Multiple studies have conrmed that out-
comes following salvage surgery for locally
recurrent colon cancer are strongly associated
with completeness of resection. It is therefore
imperative to plan for radical surgery with en
bloc resection of any involved adjacent structures to obtain microscopically negative margins (R0). Patients with LR can frequently
present with associated physiologic decits
such as malnutrition, anemia, and immunosuppression from cytotoxic medications.
Appropriate preoperative planning should,
whenever possible, include addressing these
decits with enteral (or if needed parenteral)
nutritional supplementation, iron or blood
supplementation, and a sufcient break from
chemotherapy to allow for blood count normalization. While some selected patients can
be treated with a laparoscopic approach, the
majority of patients will require open surgery
with a midline incision to allow for optimal
assessment of disease extent and oncologic
resections. Surgical oncologic principles need
to be followed, including minimal handling of
the tumor, wound protection, high ligation of
lymphovascular pedicles, and en bloc resection of involved adjacent structures. The liver
and peritoneum should be carefully inspected for
any evidence of metastatic disease. When in
doubt, intraoperative ultrasound and frozen
sections should be obtained. Liberal use of
ureteral stents can aid in the identication of
the ureters, especially for tumors involving
the retroperitoneum. Anastomotic recurrences
will require resection of the anastomosis and
supplying mesentery. Given the history of previous resections in these patients it is important to carefully assess the blood supply to the
remaining colon. In patients at increased risk
for anastomotic leaks, judicious use of diverting stomas can minimize the risk of abdomino-pelvic infections that could prevent the
timely completion of postoperative chemotherapy. It has been shown that as long as an
R0 complete resection is achieved, neither the
extent of surgery nor the performance of multivisceral resections are predictors of poor
outcomes. It is therefore recommended to
resect adherent structures or organs and avoid
attempts at dissection to prevent potential
tumor spillage and recurrence. Resections
may encompass adjacent solid organs such as
pancreas, spleen, liver, urological, or gynecological structures, other segments of bowel, or
the abdominal wall. Oligometastatic synchronous liver disease can either be addressed concomitantly or in a staged fashion. For primary
colon cancer presenting with synchronous
resectable liver metastases there are studies
supporting either approach. There are limited
data in the recurrent colon cancer setting,
however we usually recommend a staged
approach for liver disease requiring hemihepatectomies or extended resections.
H. There are few small series specically
describing the outcomes of patients undergoing surgery for locally recurrent colon cancer
(Table 66.1). For patients undergoing successful resections with microscopically negative margins, 5-year disease-specic survival
ranges between 25 and 46%. Conversely,
patients with residual macroscopic tumor
have dismal outcomes, conrming that in
patients with LR unsuitable for complete
resection, surgery should only be performed
for the palliation of symptoms. Other factors
66 Recurrent Colon Cancer
Table 66.1 Outcomes following curative intent surgery for locoregionally recurrent colon cancer
Study n
Taylor 2002 71 Excluded 52/26/22 70.5 24.7
Bowne 2005 100 26 56/11/19 27 35
Akiyoshi
2011
Harji 2013 42 43 18/21/3 NS 40
NS not specied
R0 microscopically negative margins, R1 microscopically positive margins, R2 macroscopic tumor remaining
a
Overall survival
b
Disease-specic survival
c
Median survival in months
Distant
metastases (%)
45 31 89/11/– 51 46
Resection R0/R1/
R2 (%)
Median F/U
(months)
5-year
survival (%)
a
b
b
a
5-year survival R0/R1/
R2
37.4/25.1/0
57/0/0
51/0/–
29/26/16
a
b
b
c
colorectal origin. CRS, as described by
Sugarbaker, refers to the surgical excision of
all visible intraperitoneal tumor deposits by
peritoneal stripping and visceral resections
when required. The CC (completeness of cytoreduction) score is used to assess the amount
of disease remaining after CRS.It ranges from
0 to 3, with CC=0 indicating that no macroscopic disease remains. Following CRS, a
heated chemotherapeutic agent (usually mitomycin-C or oxaliplatin) is intraoperatively
administered to the peritoneal cavity. Multiple
recent studies have now demonstrated that
Fig. 66.3 Heated intraperitoneal chemotherapy (HIPEC)
CRS and HIPEC can be performed safely with
low mortality and acceptable morbidity resultfound to be associated with poor outcomes
include: more than one site of LR or distant
metastases, recurrence in the mesentery/
nodal basin or peritoneum, high pathological
grade, and large tumor size.
I. Special consideration needs to be given to
patients presenting with LR in the setting of
peritoneal carcinomatosis (PC). Approximately
20–50% of patients with recurrence will present with peritoneal disease. PC from colon
cancer has traditionally been viewed as a contraindication to surgery. Even with the most
aggressive systemic chemotherapy these
patients have only a 15–24month median survival. Cytoreductive surgery (CRS) and heated
intraperitoneal chemotherapy (HIPEC)
(Fig.66.3) have been used for the treatment of
other peritoneal malignancies with promising
results. More recently these techniques have
also been used in the management of PC of
ing in 5-year survival ranging from 26 to 43%.
Despite signicant variability among studies
in the absence of standardized techniques,
there is also evidence supporting CRS and
HIPEC as a valid treatment for selected, medi-
cally t patients with peritoneal carcinomato-
sis in the setting of recurrent colon cancer.
There is emerging evidence showing that simi-
lar outcomes can be obtained even in some
patients with PC and synchronous liver
metastases.
J. It is currently unclear if patients rendered
disease-free with R0 resections benet from
adjuvant chemotherapy. While guidelines
from the National Comprehensive Cancer
Network (NCCN) recommend six months of
adjuvant chemotherapy after resection of
colorectal cancer liver metastases, they do not
specically address the usefulness of chemo-
therapy after resection of a local recurrence.
515
516
D. Liska and L. Stocchi
The decision must be individualized and is
based, in part, on whether any chemotherapy
to address LR (particularly an oxaliplatincontaining regimen) was previously administered. Select patients with close resection
margins who have not received preoperative
EBRT or IORT may benet from postoperative EBRT.Marking the area of concern with
radiopaque clips at the time of surgery can
help target the appropriate radiation eld.
K. In summary, locoregional recurrence in colon
cancer is relatively rare but when present is
associated with poor outcomes. Close surveillance of patients at high risk for recurrence can help detect LR when still curable.
Surgical treatment is the only chance for
long-term survival but is technically challenging due to local extent of the disease.
Appropriate surgical planning and anticipating the need for an extended resection with en
bloc removal of involved adjacent structures
or organs, is critical for achieving microscopically negative margins and optimal outcomes. Resectable distant oligometastatic
disease is not a contraindication to surgery
with curative intent. Well selected patients
with peritoneal carcinomatosis can benet
from cytoreductive surgery and HIPEC. A
multidisciplinary evaluation is needed to
determine an individualized approach in
terms of preoperative, surgical, and adjuvant
management.
Suggested Reading
Bowne WB, Lee B, Wong WD, Ben-Porat L, Shia J,
Cohen AM, Enker WE, Guillem JG, Paty PR, Weiser
MR. Operative salvage for locoregional recurrent
colon cancer after curative resection: an analysis of
100 cases. Dis Colon Rectum. 2005;48:897–909.
Liang TW, Sun Y, Wei YC, Yang DX. Palliative treat-
ment of malignant colorectal obstruction caused by
advanced malignancy: a self-expanding metallic stent
or surgery? A system review and meta-analysis. Surg
Today. 2014;44:22–33.
Liska D, Stocchi L, Karagkounis G, Elagili F, Dietz DW,
Kalady MF, etal. Incidence, patterns, and predictors
of locoregional recurrence in colon cancer. Ann Surg
Oncol. 2017;24(4):1093–9. Manuscript submitted for
publication. 2016
Mirnezami R, Chang GJ, Das P, Chandrakumaran K,
Tekkis P, Darzi A, Mirnezami AH. Intraoperative
radiotherapy in colorectal cancer: Systematic
review and meta-analysis of techniques, longterm outcomes, and complications. Surg Oncol.
2013;22(1):22–35.
Nadler A, McCart A, Govindarajan A. Peritoneal
carcinomatosis from colon cancer: a systematic
review of the data for cytoreduction and intraperitoneal chemotherapy. Clin Colon Rectal Surg.
2015;28(04):234–46.
Nordlinger B, Sorbye H, Glimelius B, Poston GJ, Schlag
PM, Rougier P, etal. Perioperative chemotherapy with
FOLFOX4 and surgery versus surgery alone for resectable liver metastases from colorectal cancer (EORTC
Intergroup trial 40,983): a randomised controlled trial.
Lancet. 2008;371(9617):1007–16.
Steele SR, Chang GJ, Hendren S, Weiser MR, Irani J,
Buie WD, Rafferty JF. Practice guideline for the
surveillance of patients after curative treatment
of colon and rectal cancer. Dis Colon Rectum.
2015;58(8):713–25.
Appendiceal Neoplasms
AlisonR.Althans andScottR.Steele
67
Refer toAlgorithm in Fig.67.1
A. Many tumors of the appendix present acutely,
often initially mistaken for acute appendicitis
and are only found intra-operatively or following pathology examination. Others present as asymptomatic incidental lesions during
a work-up for other symptoms (i.e., CT scan)
and allow the opportunity for a more denitive evaluation. Appendiceal tumors can be
divided into epithelial (i.e., adenoma, adenocarcinoma), non-epithelial (e.g., carcinoid),
and mixed lesions. Other rare lesions include
sarcomas, lymphomas, and mixed lesions
such as goblet cell carcinoids.
B. Appendiceal neoplasms are rare, with a
reported incidence of 1.2 cases per 100,000
people per year in the United States. In general, the history and physical examination are
non-specic. Patients are often over 50years
of age, with a mean age of 62–65years, and
there is a slight male predominance. In many
cases, patients are asymptomatic, especially
in early stage disease. Those patients with
symptoms may present with right lower
quadrant abdominal pain (mimicking appen-
A. R. Althans
Department of Surgery, University of Pittsburgh
Medical Center, Pittsburgh, PA, USA
S. R. Steele (*)
Department ofColorectal Surgery, Cleveland Clinic,
Cleveland, OH, USA
dicitis), which is classically from obstruction
of the lumen by the tumor. As disease progresses, mucin throughout the abdomen (i.e.,
pseudomyxoma peritonei) may lead to
abdominal distension, obstructive symptoms
and even a mass. Unfortunately this indicates
advanced disease.
C. Radiological evaluation is one of the most
important aspects for evaluation. Plain
radiographs may be indicated in those
patients with a concern for obstruction or
perforation, although non-specic. Crosssectional imaging with CT is useful both in
the initial evaluation as well as for surveillance. CT will help in the staging of mucinous adenocarcinoma to evaluate for lymph
node and distant metastases. CT will also
help with calculation of the peritoneal cancer index (PCI) (Fig.67.2). Abdominal MRI
has been incorporated in several surveillance
strategies to follow solid and mucinous peritoneal disease. Both allow for evaluation of
the appendix as well as the entire abdomen
(Table 67.1). Fluoroscopic studies such as
small bowel follow-through and gastrogran
enema are seldom indicated as primary studies. PET scans may be helpful for solid
tumors to detect recurrence but typically are
unreliable for small lesions <1 cm and not
helpful for detecting pseudomyxoma peritonei. Somatostatin receptor scan may be used
in those patients with carcinoid tumors
>1cm to help detect distant disease.
© Springer Nature Switzerland AG 2020
S. R. Steele etal. (eds.), Clinical Decision Making in Colorectal Surgery,
https://doi.org/10.1007/978-3-319-65942-8_67
517
518
A. R. Althans and S. R. Steele
Fig. 67.1 Algorithm for appendiceal neoplasms.
∗Appendectomy for <1cm lesions and negative margins;
Right colectomy for >2cm lesions, positive (or questionable) margins, nodal involvement, invasion of mesoappendix >3 mm, or metastases to the liver only;
Chemotherapy for diffuse metastases >1 site; $ May
D. There is no diagnostic laboratory test for the
majority of the appendiceal tumors.
Laboratory testing may include baseline
CBC, chemistry and coagulation panels as
indicated by appropriate risk stratication.
For patients with suspected epithelial lesions,
the tumor marker carcinoembryonic antigen
(CEA) should be evaluated. Carcinoid lesions
may be evaluated with urinary 5-HIAA
metabolites and serum chromogranin A.
E. Endoscopy is not classically useful to detect
the primary lesion. In some cases, mucin
may be visualized extruding from the appendiceal orice that may suggest the presence
of a mucinous neoplasm. More importantly,
those patients with an appendiceal neoplasms
including carcinomas, carcinoid and neuroendocrine tumors have an ~10–20% risk of
require HIPEC and cytoreduction in the setting of diffuse
mucinosis; ∗∗ Diffuse mucinosis with PCI <16–20, or
perforated primary without pseudomyxoma peritonei; #
Diffuse mucin or carcinomatosis with PCI >16–20, diffuse systemic metastases, or carcinomatosis with concomitant metastases
concomitant lesions elsewhere in the colon.
Prior to any surgical intervention, endoscopic
clearance of the colon should be performed.
F. Nomenclature for mucinous neoplasms of
the appendix is evolving and contributes
somewhat to the confusion regarding the
optimal treatment. In general, low-grade
mucinous neoplasms encompass serrated or
villous adenomas, cystadenoma, or mucinous neoplasms of uncertain behavior. Of
note, mucocele is a morphologic term to
describe a dilated uid lled appendix, and
does not relate to the biological aggressiveness. They are slow-growing and typically
indolent. They may rupture (or iatrogenically
ruptured during surgery), leading to mucin
throughout the abdomen. Localized tumors
may typically be treated with appendectomy
Peritoneal Cancer Index
67 Appendiceal Neoplasms
519
1
80 4
23
Regions Lesion size Lesion size score
0. Central
1. Right upper
2. Epigastrium
3. Left upper
4. Left flank
5. Left lower
6. Pelvis
7. Right lower
8. Right flank
9. Upper jejunum
10. Lower jejunum
11. Upper ileum
12. Lower ileum
PCI
11
567
12
LS 0 No tumor seen
LS 1 Tumor up to 0.5 cm
LS 2 Tumor up to 5.0 cm
LS 3 Tumor > 5.0 cm
or confluence
9
10
Fig. 67.2 Peritoneal Cancer Index (PCI). This is a collective score with a maximum of 39 points from nine abdominal
squares and 4 small bowel segments. Each area is scored between 0 (no disease) to 3 (deposits are >5cm)
and have good long-term prognosis. If epithelial cells are present outside the appendix
in the peritoneum, this may lead to more
aggressive behavior and result in pseudomyxoma peritonei (refer to section I in
algorithm in Fig.67.1).
G. Carcinoid (Neuroendocrine) tumors of the
appendix are derived from hormone-active
neuroendocrine cells. While various hor-
mones (growth hormone, calcitonin) may be
produced, most commonly they secrete serotonin, which is subsequently metabolized to
5-hydroxyindoleacetic acid (5-HIAA). This
metabolite is excreted in the urine and classically used to monitor disease. The majority
are located at the tip of the appendix, are less
than 1cm, and when large can be associated
with a desmoplastic inammatory response
520
A. R. Althans and S. R. Steele
Table 67.1 Characteristics of Appendiceal Neoplasms
on Cross-Sectional Imaging
Lesion Appearance
Mucocele Encapsulated dilated appendix
Adenocarcinoma Mucinous: Soft tissue mass-like
Carcinomatosis Mucin or clusters of tumor
Carcinoid Most commonly normal or with
Pseudomyxoma
Peritonei
a
Many lesions may present with localized appendiceal
inammation consistent with acute appendicitis or may be
not visualized on cross-sectional imaging
lled with intraluminal mucin ±
calcications
lesion with cystic dilation and
possible invasion through the wall
± disseminated mucin throughout
the abdomen;
Non-mucinous: Soft tissue
mass-like lesion with cystic
dilation with possible invasion
through the well±
lymphadenopathy ± liver
metastases
throughout the peritoneum with
involvement of peritoneal surface,
parenchyma and/or omentum
localized inammation;
Occasionally with soft-tissue
mass within the appendix or
diffused mural thickening
Intra-peritoneal low attenuation
mucin (ascites) ± serosal implants
a
in the mesentery. Outcomes correlate with
stage, of which size is the primary factor
(Table67.2). While lymph node involvement
is rare in lesions <1cm, up to 30% of carcinoids over 2cm will have nodal metastases.
In general, outcomes are good, with 5-year
survival for tumors limited to local and
regional disease >80%; though 25–30% for
stage IV disease. Goblet cell carcinoid represents a mixed epithelial and neuroendocrine tumor variant that presents with a wide
spectrum of biological aggressiveness.
Whereas the majority are incidental ndings
on appendectomy, ~10–15% will present
with metastatic disease. Outcomes are typically worse than routine carcinoids with
5-year survival for patients with local/
regional disease 45–82%, and those with
stage IV disease <20%.
H. Lymphoma and sarcoma represent less com-
mon tumors than may be found in the appendix. Lymphoma is more common among
Table 67.2 AJCC (seventh Edition) Staging Systems for
Primary Appendiceal Neuroendocrine Carcinoma
AJCC
Tumor
T1a
≤1cm greatest diameter
T1b 1–2cm greatest diameter
T2
>2cm but ≤4cm or invasion of cecum
T3 >4cm or extension to ileum
T4 Perforates peritoneum or invades other organs
Nodes
N0 No regional lymph node involvement
N1 Metastasis to regional nodes
Metastasis
– –
M0 No distant metastasis
M1 Distant metastasis
Stage
– –
I T1, N0, M0
II T2/3, N0, M0
III T4, N0, M0
Any T, N1, M0
IV Any T, any N, M1
I T1, N0, M0
AJCC American Joint Committee on Cancer
these more rare conditions, yet the appendix
may be the primary disease site. Patients are
commonly 30–40years old, and commonly
present in with symptoms of appendicitis or
obstructive symptoms from intussusception
or local inammation. Sarcomas are much
rarer, with Kaposi’s sarcoma and leiomyosarcoma among the subtypes.
I. Pseudomyxoma peritonei may occur in the
setting of appendiceal tumors or those from
peritoneal or ovarian sources. This process is
describes mucin to varying degrees in the peritoneum as well as strong and mucinous epithelial cells. In the setting of appendiceal
neoplasms, it results from a rupture of lowgrade mucinous neoplasms. The outcome is
directly proportional to the amount of mucin,
which is a result of the degree of epithelial cell
presence or absence in the mucin. Often this
will be conned to the right lower quadrant,
but may also present as disseminated peritoneal adenomucinosis or peritoneal carcinomatosis. The former may spread throughout the
abdominal cavity, whereas the latter may also
inltrate the abdominal organs.
67 Appendiceal Neoplasms
521
J. Adenocarcinoma of the appendix may include
mucinous and non-mucinous subtypes. These
tumors may rupture and lead to seeding of the
peritoneal cavity and pseudomyxoma peritonei.
These tumors invade the appendiceal wall and
may spread by both nodal (less commonly) and
peritoneal surfaces. Non-mucinous adenocarcinoma of the appendix closely resemble colonic
adenocarcinoma with metastases more commonly to the lymph nodes and hematogenously
to the liver. Outcomes correlate to colon cancer
and are determined by the stage (Table 67.3).
Mucinous subtypes have a comparatively worse
prognosis than non-mucinous lesions. A variant
of mucinous adenocarcinoma is the signet ring
cell subtype that is much more aggressive and
tends to lead to diffuse metastases throughout the
Table 67.3 ACJJ staging (8th edition) of mucinous adenocarcinoma of the appendix
Primary tumor (pT)
T stage
• TX:primary tumor cannot be assessed
• T0:no evidence of primary tumor
• Tis:carcinoma in situ, intramucosal carcinoma (involvement of lamina propria with no extension through
muscularis mucosae)
• T1:tumor invades submucosa (through the muscularis mucosa but not into the muscularis propria)
• T2:tumor invades muscularis propria
• T3:tumor invades through the muscularis propria into the pericolorectal tissues
• T4
– T4a:tumor invades through the visceral peritoneum (including gross perforation of the bowel through tumor
and continuous invasion of tumor through areas of inammation to the surface of the visceral peritoneum)
– T4b:tumor directly invades or adheres to other adjacent organs or structures
Notes
• Tis and T1
– Tis in the AJCC 8th edition refers only to intramucosal carcinoma, a lesion with invasion into the lamina
propria that does not penetrate the muscularis mucosa
– Unlike in the 7th edition, lesions with high grade dysplasia without invasion into the lamina propria are
not considered Tis and these lesions have no potential to spread
– Term intraepithelial carcinoma is synonymous to Tis but is rarely used (and may be misleading)
– True intramucosal carcinoma also lacks the potential for metastasis; however, because of the potential for
missing invasion beyond the muscularis mucosa due to incomplete sampling, designating these lesions Tis is
appropriate
– T1 lesions have invasion into the submucosa
• Carcinoma in a polyp
– Classied according to pT denitions used for colorectal carcinomas; i.e. invasive carcinoma in the muscularis
mucosae or lamina propria is pTis and tumor that has entered the submucosa of the polyp’s head or stalk is pT1
– If a resected polyp has a clear margin during endoscopic resection, it is a pTis lesion and the nodal and
metastatic status is unknown; however, the risk of metastatic disease is very low and lymph node
dissection is not indicated
– Several professional societies recommend resection if there is a high grade invasive tumor, the invasive
tumor is 1mm or less from the resection margin or lymphovascular space invasion is present
peritoneal cavity. It characteristically has a very
poor prognosis.
K. As many lesions are incidental ndings or
originally felt to represent appendicitis,
appendectomy is one of the more common
“diagnostic” modalities for appendiceal
neoplasms. However, appendectomy en
bloc with resection of the mucinous lesion
may also be curative for localized, non-ruptured benign lesions, carcinoids <1cm with
negative margins, and benign mucoceles.
When dealing with the latter, it is important
to avoid perforation and spillage to minimize the changes of peritoneal mucinosis.
Carcinoids 1–2cm with otherwise negative
features and clear margins may be candidates for therapy with an appendectomy;
(continued)