Chapter 35 - Small Bowel++ Flashcards
What is absorbed in the small intestine?
nutrients and water
What is absorbed in the large intestine?
Water
In what portion of the duodenum are most ulcers?
bulb- 90% (1st part of duodenum)
What is contained in the second/descending portion of the duodenum?
ampulla of vater and duct of santorini
What portions of the duodenum are retroperitoneal?
descending (2nd) and transverse (3rd)
vascular supply of duodenum superiorly? inferiorly?
GDA superiorly, Inferior pancreaticoduodenal inferiorly
How long is the jejunem? how large are the vasa recta (long or short)?
100cm, long vasa recta
The jejunum is the maximum site of absorption for everything except:
- iron - duodenum
- Ca - duodenum
- B12 - terminal ileum
- Bile acids - ileum/terminal ileum
What percentage of NaCl is absorbed in the jejunum? water?
95%; 90%
What is the vascular supply of jejunum?
SMA
Hos long is the ileum?
150cm, short vasa recta, flat. Vascular supply from SMA
What is absorbed at the intestinal brush border?
maltase, sucrase, limit dextrinase, lactase
What is the normal diameter of small bowel? transverse colon? cecum?
3 6 9cm.
What is the terminal branch of the SMA?
Ileocolic
What do goblet cells do?
mucin secretion
What do paneth cells do?
secretory granules, enzymes
What do enterochromaffin cells do?
APUD, 5-Hydroxytryptamine release, carcinoid precursor
What do brunner’s glands produce?
alkaline solution
What are peyer’s patches? Where are they increased?
lymphoid tissue; increased in the ileum
What are M-cells?
antigen presenting cells in intestinal wall
What are the phases of gut motility?
I - Rest
II - acceleration and gallbladder contraction
III - peristalsis
IV - deceleration
Motilin is most important hormone in migrating motor complex
What is fat and cholesterol broken down by?
cholesterol esteras, phospholipase A, lipase, colipase in combination with bile salts -form micelles -TAG’s are reformed in intestinal cells and released as chylomicrons
What are chylomicrons made up of?
90%TAG’s, 10% phospholipids, cholesterol, protein
What percentage of bile salts are reabsorbed?
95% -50% passive- 45% ileum and 5% colon -50% active resorption in terminal ileum -conjugated bile is only absorbed in terminal ileum
What is bile acid conjugated to?
taurine and glycine can be deconjugated in the colon by bacteria and absorbed there
What are the primary bile acids?
cholic and chenodeoxycholic
What are the secondary bile acids?
deoxycholic and lithiocholic (from bacterial action on primary bile acids in the gut)
What can happen with the gall bladder after a terminal ileum resection?
develop stones secondary to inability to reabsorb bile salts
How is short gut syndrome diagnosed?
- symptoms, not length of bowel
- diarrhea, steatorrhea, weight loss, nutritional deficiency
- lose fat, B12, electrolytes, water
What is a sudan red test?
checks for fecal fat
What is a schilling test?
checks for B12 absorption -radiolabeled B12 in urine
how much bowel do you need to survive with TPN?
75cm, 50cm with a competent ileocecal valve
What is the pathology of hypersecretion causing steatorrhea?
gastric hypersecretion of acid- increases motility- interferes with fat absorption -Interruption of bile salt resorption- interferes with micelle formation
Tx:control diarrhea- lomotil, codeine, decreased oral intake
Causes of Non-healing fistula?
FRIENDS F foreign body R radiation I irritable bowel E epithelialization N neoplasm D distal obstruction S sepsis/infection
High output fistulas normally occur where?
proximal bowel and are less likely to close with conservative management
What are most fistulas caused by?
iatrogenic -treat conservatively first -40% close spontaneously -can resect bowel secoment and perform primary anastamosis
Obstruction without previous surgery usually caused by what?
small bowel- hernia large bowel- cancer
Obstruction with previous surgery usually caused by what?
small bowel- adhesions large bowel- cancer
symptoms of bowel obstruction?
nausea, vomitting, crampy pain, failure to pass gas or stool -x-ray shows air fluid level, distended loops of small bowel, distal compression
What is the air with bowel obstruction from?
swallowed nitrogen
Conservative treatment for SBO?
NG IVF -cures 80% of partial SBO, 20-40% of complete SBO
What are the surgical indications for bowel obstruction?
Progressing pain, peritoneal signs, fever, increasing of WBC’s, signs of strangulation or perforation, failure to resolve
What is gallstone ileus?
-SBO from gallstone in terminal ileum -Air in biliary tree with SBO -caused by fistula bw gall bladder and second portion of duodenum -tx with stone removal -if sick leave fistula -if ok remove gall bladder, fix bowel
What is meckel’s diverticulum?
-A true diverticulum -2% of population -2 feet from ileocecal valve -fist 2 years of life
What is meckel’s diverticulum caused by?
failure of closure of omphalomesenteric duct 50% of all painless lower GI bleeds in children under 2
What is the most common tissue type found in meckel’s diverticulum? most common to cause bleeds?
Pancreas is most common type. Gastric mucosa most common to bleed
What is the most common presentation of meckels in adults?
obstruction
How do you localize a meckels?
Meckel’s scan (99Tc)- can do diverticulectomy
What do you do with duodenal diverticula?
- observe unless symptomatic; need to rule out gallbladder disease as a cause
- duodenal>jejunal>ileal
- segmental resection vs excision if intraluminal
What are the first signs of Crohn’s disease?
Intermittent abdominal pain, diarrhea, weight loss, low grade fever -usually 15-35 at first presentation -increased in ashkenazia J’s
What are the extraintestinal manifestations of crohn’s?
arthritis, arthralgias, pyoderma gangrenosum, erythema nodosum, ocular diseases, stunted growth, B12/Folate deficiency
What is most comon first involved bowel portion in Crohn’s?
terminal ileum (40%) -10% anal perianal first -colon only 35% -small bowel only 20%
What is the pathology of Crohn’s disease?
transmural involvement segmental- skip lesions, cobblestoning, narrow deep ulcers, creeping fat fistulas
What is medical tx of Crohn’s?
5-ASA, sulfasalazine, steroids, azathioprine, methotrexate, remicade, Loperamide
What are the surgical indications for Crohn’s?
- obstruction
- abscess
- hemorrhage
- blind loop obstruction
- EC fistula
- Perineal fistula
- ano/rectovaginal fistulas
What do u do with incidental finding of IBD with normal appendix in presumed appendicitis?
take appendix if cecum not involved
When is stricturoplasty indicated in patients with Crohn’s?
diffuse or recurrent strictures (failed endoscopic dilation), save small bowel length, 10% leakage/abscess/fistula rate with stricturoplasty
What are the complications from removal of terminal ileum?
- decreased B12 uptake (megaloblastic anemia)
- decreased bile salt uptake (leads to increased hepatic production and gallstones)
- decreased oxalate binding secondary to increased intraluminal fat that binds calcium (leads to Ca oxalate kidney stones)
What are kulchitsky cells?
produce serotonin (enterochromoffin cell or argentaffin cells)
what is the breakdown product of serotonin?
5-HIAA can be found in urine
serotonin is part of what GI system?
amine precursor uptake decarboxylase system - APUD
what is the precursor to serotonin?
tryptophan
what can increased levels of tryptophan lead to?
niacin deficiency and pellagra
other than serotonin, what do carcinoid tumors also secrete?
bradykinin
When do you get carcinoid syndrome?
- bulky liver mets
- flushing and diarrhea, asthma symptoms, and right heart valve lesions
how do you treat carcinoid syndrome?
- all pts get abdominal exploration unless unresectable
- if resecting liver mets, also do cholecystecomy
What are the GI sx in carcinoid caused by?
vasoconstriction and fibrotic desmoplastic rxn
what is a good test for localizing carcinoid when cant find it on CT?
octreotide scan
where is the most common site for carcinoid?
appendix
small bowel carcinoid is at increased risk for what?
multiple primaries and second unrelated malignancies
what do you do with carcinoid in appendix?
2 cm or involving base - right hemi
what do you do with carcinoid anywhere else in GI tract?
treat like ca- segmental resection w lymphadenectomy
What is chemo for carcinoid?
streptozocin and 5FU
what is a palliative tx for carcinoid?
octreotide
what do you do for bronchospasm in carcinoid? flushing? false 5-HIAA is from what? what can exacerbate sx?
Aprotinin
alpha blockers
fruits
pentagastrin
What causes intussusception in adults?
- small bowel or cecal tumors
- presents with bleeding or obstruction
- tx: oncologic resection (ie w/ lymphadenectomy)
what is most common small bowel tumor?
leiomyoma- usually extraluminal
where are most adenomas of small bowel found?
ileum
what inheritence is peutz-jehgers? What are sx?
- autosomal dominant
- jejunal and ileal hamartomas
- mucocutaneous melanotic skin pigmentation
- extraintestinal malignancies
- slight increase in colon ca
- lipomas, neurogenic tumors
- hemangiomas
what is most common small bowel malignancy?
- adenocarcinoma
- most in duodenum
- may need whipple
- carcinoid is becoming more prevalent
what are risks for duodenal ca?
- FAP
- Gardners
- polyps
- adenomas
- von Recklinghausen
where are leiomyosarcomas of small bowel usually found?
- jejunum and ileum
- most extraluminal
- hard to differentiate from leiomyoma
where are small bowel lymphomas usually found?
- ileum - greatest concentration of gut-associated lymphoid tissue
- tend to be large (>5cm)
- up to 25% present as perforation
- mediterranean variant occurs in young males
- they get clubbing
what is obstruction rate with loop ileostomies?
1-2%
what types of ostomies have increased risk of parastomal hernia?
loop colostomies
what is most common stomal infection?
candida
when do you get diversion colitis and from what?
Harmann’s pouch secondary to decreased short chain fatty acids- give short chain FA enemas
what is most common cause of stenosis of stoma?
ischemia tx with dilation
what are abscesses under stoma site caused by?
irrigation device
what ostomy pts have increased risk of gallstones and uric acid stones?
ileostomy
sx of appendicitis?
- anorexia
- periumbilical pain
- vomiting
- migrates to RLQ
- can have Normal WBC
most common age for appendicitis?
20-35
what does appendicitis look like on CT?
diameter >7mm, wall >2mm, looks like bulls eye, fat stranding, no contrast in lumen
What part of appendix is most likely to perf?
midpoint of antimesenteric border
when is appendicitis non-operative?
- walled off perforated appendix
- perc drainage and interval appendectomy
- f/u colonoscopy to ro perf’d colon ca
why are children and elderly more likely to perf?
- delayed dx
- kids have higher fever, vomitting, diarrhea
- elderly may be asymptomatic
- infants rarely get it
what do you do abt appendicitis in pregos?
- most common cause of acute abdominal pain in 1st tri
- more likely in second tri
- more likely to perf in third tri (confused for contractions)
- need to make incision where pain is - displaced superior
what is fetal mortality with perf’d appendix?
35%
what is a mucocele?
- can be benign or malignant
- mucous papillary adenocarcinoma - right hemi
- if malignant - can get pseudomyxoma peritonei w/ rupture
What percentage of pts with regional ileitis go on to have Crohn’s?
10%
what do you do if you have presumed appendicitis but find ruptured ovarian cyst or thrombosed ovarian vein?
do appy anyway
most common cause of ileus?
- surgery
- trauma
- hypokalemia
- ischemia
- drugs
- dilatation is uniform
What do you get with typhoid enteritis?
- bleeding/perforation
- fever
- headaches
- maculopapular rash
- leukopenia
- tx with bactrim
What gestational layers are the small bowel derived from?
endoderm (epithelial lining) and mesoderm (muscle and connective tissue)
Where does the omphalomesenteric duct (vitelline duct) originate from? (fore, mid, or hindgut)
midgut
During intestinal development, failure to complete the 270-degree rotation around the SMA causes what pathology?
intestinal malrotation
At the confluence of the pre-arterial and post-arterial (SMA) intestinal segments, the vitelline duct joins the yolk sac and is obliterated before delivery. What is the pathology caused by the failure of this process?
Meckel diverticulum
What are the portions of the duodenum?
- bulb
- retroperitoneal, plicae circulares (dissect for Kocher) - contains ampulla, the “C”
- inferior horizontal portion
- after the SMA/SMV crosses the duodenum (SMA syndrome occurs here)
Chance fractures at the 2nd and 3rd lumbar vertebra can cause injury to what portion of the GI tract?
duodenum
What portion of the duodenum is intimately associated with the uncinate process and important during surgical resection of the pancreas?
third
Where does the ligament of Treitz originate from?
the right diaphragm crus
The blood supply to the first portion of the duodenum?
GDA and supraduodenal branch of the proper hepatic artery
What is the blood supply to the second and third portions of the duodenum?
the superior anterior and posterior pancreaticoduodenal arteries as well as the inferior anterior and posterior; these are branches from the GDA and SMA
The fourth portion of the duodenum receives its blood supply from what?
the jejunal branch of the SMA
What are some differences between the jejunum and ileum?
What is the terminal artery of the SMA?
the ileocecal artery
What are the blood vessels supplying the jejunum from the SMA?
the vasa recta
What is the strongest layer of the bowel?
submucosa
What layer is the myenteric plexus of Meissner in?
submucosa
In the duodenum where are the Brunner glands? What do they do?
submucosa, secrete mucus and bicarb to neutralize acids
What layer are the Peyer patches in the ileum, what do they do?
submucosa
Enteroendocrine cells (aka APUD) secrete what?
GLP-1 and 2, gastrin, serotonin, substance P, VIP
Enteroendocrine cells can give rise to what type of pathology
carcinoid
What do goblet cells do in the small intestine?
secrete mucus - lubricate and protect
What are the Paneth cells of the small intestine?
full of mitochondria, ribosomes, lysosomes - microorganism defense
Where does most protein digestion and absorption occur?
duodenum and proximal jejunum, require around 1g/kg/d; body cannot use nitrogen efficiently, so it is excreted in urine as urea
Describe protein digestion
- starts in stomach: pepsin from chief cells in fundus
- pepsin secreted 2/2 acidic env, gastrin, vagal
- duodenum and jejunum: pancreatic peptidases
- proteins degrade to AAs, dipeptides, tripeptides
- cotransported with Na into cytoplasm
What protein transports glucose and galactose into the small intestine cell?
SGLT-1
How does glucose get into the portal system?
Na-K-ATPase dependent pump through GLUT-2; constant supply needed for CNS and RBC fct
What does the majority of fat come in the form of?
cholesterol and phospholipids - essential for plasma membrane structure and function
Describe fat digestion
- mostly occurs in proximal small bowel
- duodenum senses acid from stomach, release CCK from I cells
- pancreas releases lipase, liver releases bile, gallbladder contracts, sphincter of Oddi relaxes
- lipase - cleaves triglycerides to fatty acids (short, med, long)
- products mix with bile - micelles (water soluble) - enter cell
- in cell, triglycerides reform - form larger chylomicron
- thoracic duct, then SVC
What are some of the different properties of short, medium, and long-chain fatty acids?
- short - water-soluble, used as fuel source enterocytes
- medium - water-soluble, portal circulation, not in typical diet
- long - primary energy storage, precurors to inflammatory mediators
Where is calcium absorbed? How?
- duodenum
- stimulated through basolateral Ca-ATPase pump
- hypocalcemia leads to PTH release
- vit D increased - stim Ca-ATPase - Ca released into systemic circulation
Where is iron absorbed?
- duodenum
- Fe2 state more easily absorbed
- DMT1 is brush border transporter
- ascorbic acid and ferric reductase make iron easier to absorb
Describe B12 absorption
- required for cellular nucleic acid production and mitosis
- absorbed in terminal ileum (also bile)
- binds with intrinsic factor from gastric parietal cells
- taken up by transcobalamin 2 receptor
- loss of transcobalamin 2 receptor or IF leads to hypersegmented neutrophils and megaloblastic anemia
Where is ADEK absorbed?
jejunum
Describe the small bowel’s role in immunology?
- tight jcts b/w epithelial cells can disrupt and allow translocation
- mucus inhibits bacterial growth, movement, attachment
- Paneth cells produce toxic metabolites
- M cells endocytose material to distribute to dendritic cells/macs
- Peyer patches (most in ileum) - lymphocyte proliferation (can be lead point in intussuscx)
- IgA prevents migration, neutralizes toxins
How does erythromycin improve small intestine forward flow?
- binds motilin receptor
- causes MMC (basal pacemaker rhythm of SB)
Where does the intestinal microbiome develop from?
- breast milk
- vaginal canal
How do you manage GIST?
- all greater than 2 cm should be resected w/o LADx
- locally adv/metastatic - neoadj imatinib
- if KIT+, and high risk of recurrence - adj imatinib
- CT/MRI f/u q6 mo while taking adj, then cont close f/u after completion
- small, low-risk tumors may not need f/u
Short segment strictures (5-7 cm) should get what stricturoplasty?
Heinecke-Mikulicz - longitudinal incision with transverse closure
Focal (<5 cm) strictures should be treated how?
can attempt endoscopic dilation if proximal, otherwise resection or Heineke-Mikulicz)
When is bowel resection indicated for small bowel stricture in Crohns?
segment of small bowel is inflamed or perforated or when there is an abscess or fistula to an adjacent organ
ileocecal resection is performed when the terminal ileum is involved with Crohn disease
margins do not have to be pathologically negative and can include limited ulcers, take margins to palpably normal tissue
How could you manage medium strictures (10-15 cm)?
Finney stricturoplasty - fold stricture into “U,” longitudinal incision, sew opposed edges together
How could you manage a long (>15 cm) stricture?
Michelassi - divide stricture, stack in continuity, divide longitudinally, sew opposing edges in a side-to-side isoperistaltic fashion
In patients with malignant bowel obstruction, what is a good pharmacological option that can help resolve nausea/vomiting?
octreotide
In patients with NOMI, what vasodilator can be infused if supportive therapy has been maxed out?
papaverine
In a patient previously treated for advanced cancer undergoes ex-lap for SBO. Serosa of the distal small intestine appears gray and opaque on surgery. What is this consistent with?
radiation injury
can lead to chronic, recurrent partial small bowel obstructions
What intestinal abnormality is congenital diaphragmatic hernia associated with?
malrotation
strong predilection, found in up to 20% of patients with CDH
How do you manage local duodenal adenocarcinoma?
- 1st/2nd portion: pancreaticoduodenectomy
- 3rd/4th portion: segmental resection
- do regional lymphadenectomy
adenocarcinoma more likely to present proximally (as opposed to lymphoma and carcinoid - ileum); can bleed and obstruct
If a feeding jejunostomy falls out, how do you manage this?
- Make sure there is no peritonitis.
- Tube replacement at the bedside.
- If the tube is easily replaced, position in the intestinal lumen should be confirmed with a fluoroscopy study.
- If the tube cannot be easily replaced and the time from surgery is less than 10 days, the patient will require emergent exploration for tube replacement and to avoid possible peritoneal contamination.
- If the tube has been in place for at least 10 days, the tube may be replaced electively either in the operating room or with fluoroscopy guidance by IR.
High ileostomy output is defined as…
greater than 1200 mL/d.
Loperamide can be used. Control lytes and monitor fluid status.
Advantages of g-tube vs j-tube
bolus feeding, ability to decompress, decreased risk of obstructing tube
How is decision-making for ileostomy vs colostomy made?
- For temporary loop ostomy for diversion only: loop ileostomy
- Reversal is easier compared with loop colostomy.
- For permanent or immediate fecal diversion: colostomy
- Particularly in older patients.
- Has dec for dehydration, lyte abnormalities.
A patient s/p colectomy w/ end ileostomy for cancer is set to undergo chemo but develops an ileostomy prolapse. How do you manage this?
The best treatment for ileostomy prolapse is to take down the ileostomy (rather than simply revise it), which can wait until the patient finishes chemotherapy unless he has severe symptoms or ischemia.
Pt w/ FAP is discovered to have an ulcerated 3-cm periampullary mass. Biopsy shows to be a villous adenoma with high-grade atypia. What is your approach to the management of this patient?
Pancreaticoduodenectomy
Large, periampullary, sessile polyps with histologic evidence of high-grade atypia harbor a high risk of occult invasive cancer and so should be definitively resected with radical surgery.
How do primary neuroendocrine tumors of the small bowel tend to present?
- if metastatic past liver, can cause sx associated w/ endocrine disease
- don’t perforate often (as opposed to lymphoma)
- more likely to obstruct (as opposed to adenocarcinoma)
- can bleed
What extra-intestinal manifestations do not improve after resection of diseased bowel in Crohn’s.
hepatobiliary manifestations (primary sclerosing cholangitis and cirrhosis) and axial arthropathies (ankylosing spondylitis and sacroiliitis) do not resolve following resection
How do you manage duodenal Crohn’s stricture?
- Duodenal Crohn’s involving 1st and 2nd portions: gastrojejunostomy and vagotomy. Some form of vagotomy is necessary to avoid marginal ulcers.
- Refractory strictures of 3rd and 4th portions: duodenojejunostomy.
- Stricturoplasty can be used to avoid resection and conserve bowel for short strictures in the jejunum and ileum.
- Pancreaticoduodenectomy is NOT performed for duodenal Crohn’s stricture (as opposed to adenocarcinoma or high-grade adenoma in FAP).
Discuss mesenteric cysts.
- rare, benign; but more common than omental
- most commonly in small bowel, ileum
- psx: nonspecific abdominal symptoms or as an incidental finding on routine imaging
- dx: unilocular with solid component on imaging
- tx: all get enucleation/cystectomy - may require resection of associated bowel if resection of the cyst results in compromise of blood supply to adjacent bowel; rarely will need resection
PD catheters:
Where is the catheter placed?
What do you do if you find an incidental hernia?
How extensive does adhesion lysis need to be?
How long do pts have to wait before catheter use?
- rectovesical/rectouterine
- mesh repair intraop to prevent cath compx
- selective LoA
- normally 1-2 wks; 4-6 wks w/ hernia repair
What are the top 2 presentations of pseudomyxoma peritonei?
- increasing abdominal girth
- inguinal hernia
- CT scan shows liver scalloping
- 2/2 rupture of tumor
- Tx: HIPEC
What is the most common cause of chylous ascites (abdominal chyle) in the Western world?
- malignancy, specifically lymphoma
- In the developing world, it is 2/2 TB and filiariasis
- malignancy causing obstruction of lymphatic vessels at the base of the mesentery or the cisterna chyli
How do you manage duodenal polyps in patients with FAP?
- complete polypectomy at time of discovery (endoscopic)
- ongoing surveillance
- severity of Spigelman score guides tx (number, size, histology)
- <4 is better, >20 is bad
- size <4mm better, >10 mm is bad
- tubulous is better, villous is bad
- low grade is better, high grade is bad
- Stage 0-III get increasingly more frequent surveillance
- Stage IV can get duodenectomy
How do you manage unruptured appendiceal mucinous neoplasms?
- standard appendectomy for most cases
- decision for more extensive resection can be made intraoperatively
- can also be planned in patients with a complicated radiographic mucocele with involvement of the terminal ileum or cecum, and in patients with known adenocarcinoma with mesenteric or adjacent organ involvement
- to ensure a complete resection of the lesion at appendectomy, can include a cuff of the cecum with the appendiceal specimen without encroaching on the ileocecal valve
- if the base of the appendix is involved in the disease process so that a clear margin cannot be achieved by stapling, a partial cecectomy (with preservation of the ileocecal valve), ileocecectomy (resecting the ileocecal valve), or right colectomy can be performed; goal is clear margin
- can resect the mesoappendix with the specimen so that the regional lymph nodes can be analyzed
- if a right hemicolectomy is performed to achieve a negative resection margin, it should follow oncologic principles with high ligation of the ileocolic pedicle at its base
- more extensive lymphadenectomy or routine right hemicolectomy performed solely to increase lymph node yield is not necessary for mucinous neoplasm of the appendix
- unlike intestinal-type appendiceal tumors, rarely involves nodes
- do not perform intraoperative frozen section during resection of appendiceal mucinous lesions, as the pathologies of these lesions are most often complex and unlikely to be diagnosed based upon a single frozen section.
How do you manage ruptured appendiceal mucinous neoplasm?
- rupture may result in peritoneal dissemination, so careful handling and resection of the lesion is paramount
- resect the appendix, place in a retrieval bag before extraction
- if lesion has ruptured but rupture is walled off, right hemicolectomy can be done to remove the contained rupture
- more extensive surgery aimed at clearing peritoneal mucinous disease (ie, formal cytoreductive surgery) should only be conducted by surgeons with extensive experience with peritoneal malignancies after the return of final pathology
- at nonspecialized centers, the initial surgery for a ruptured appendiceal mucinous lesion should be limited to an appendectomy or right hemicolectomy, peritoneal washing with fluid cytology, careful inspection of the abdominal cavity with documentation, and biopsy of any suspicious peritoneal lesions
- the abdomen and surgical wounds should be thoroughly cleaned by irrigation to minimize tumor cell implantation
- those with gross peritoneal spread of mucin (M1a/b according to American Joint Committee on Cancer [AJCC] staging) should then be referred to a specialized center for further evaluation and management depending on the final pathology
- those with ruptured appendiceal mucinous lesion and mucin in the right lower quadrant but no gross peritoneal mucin (eg, T4a according to AJCC staging) should be closely followed with imaging and tumor markers, the frequency of which also depends upon the final pathology
