Nelson: Small Intestine and Colon Pathology Flashcards
Crohns and ulcerative colitis are both forms of…
IBD
What is IBD?
Chronic inflammation d/t inappropriate mucosal immune response to luminal bacteria
How does IBD usually present? How do you dx?
Ages 15-30 OR 50-80 (less common)
Bloody diarrhea
Clinical presentation and colonoscopy
(10-20% of patients with Crohn’s or ulcerative colitis can have extra intestinal disease, sclerosing colangitis, erythema nodoa)
How do you tx IBD?
immunosuppression & resection for refractory cases
What complications are associated w/ IBD?
- UC fulminant colitis w/ toxic megacolon → perforation
2. CD bowel stricture & obstruction w/ perforation & fistula formation
What are the characteristics of crohn’s disease?
transmural inflammation
any part of the GI tract (*ileum)
skip lesions
A pt presents w/ mild diarrhea, fever, abdominal pain as well as sxs of malabsorption.
Crohns Disease
What gross pathological signs of crohns?
- Segmental, “patchy” disease
- Longitudinal deep ulcers
- Cobblestone appearance of mucosa @ sites where transverse ulcers are also present
What are microscopica signs of Crohns?
- small erosions w/ neutrophillic infiltrate
2. non-caseating granulomas
What are the characteristics of ulcerative colitis?
ONLY mucosa and superficial submucosa
limited to colon and rectum
continuous
LEFT sided
A pt presents w/ bloody diarrhea w/ mucous discharge, abdominal pain and cramps and tenesmus.
Ulcerative colitis
How does ulcerative colitis appear grossly?
inflammatory polyps
What does ulcerative colitis appear microscopically?
crypt distortion
dense lymphoplasmacytic infiltrate
neutrophillic crypt abscess
What is diversion colitis?
SCFA def>
colitis in distal, blind segment of colon (isolated from fecal stream) following surgery w/ diverting ostomy
Tx by res-establishing normal fecal stream
What is the pathology of diversion colitis?
mucosal erythema nad friability
nodular and aphthous ulcers (can mimic IBD)
What is radiation enterocolitis?
irradiation →
damage to epithelium acutely and ischemia chronically →
Mucosal changes
What mucosal changes are seen w/ radiation enterocolitis?
patchy erythema
mucosal telangiectasia
thickened vessel walls ( hyalinization with reduced luminal diameter)
What is normal necrotizing colitis?
transmural necrosis of small and large bowel in premature infants during 1st week of life
What is microscopic colitis?
autoimmune condition associated w/ celiacs disease
What are the two main types of ulcerative colitis?
Lymphocytic & Collagenous (both display intact crypt architecture)
A pt presents w/ watery diarrhea and a normal colon exam.
Dx?
Tx?
Microscopic collitis
Glucocorticoids
What is lymphocytic colitis?
normal crypt architecture
increased intraepithelial lymphocytes
increased lymphocytic and plasma cell infiltrate in the lamina propria
What is collagenous collitis?
intact crypt architecture and a thickened subepithelial collagen layer (arrows).
How do the pathological findings of lymphocytic and collagneous colitis differ?
LC: lamina propria inflam, intraepithelial lymphocytes, & epithelium damage
CC: band of subepithelial collagen is superior to inflammation
What drugs can cause drug induced enterocolitis?
- NSAIDS: may cause gastric, proximal duodenal, jejunal, ileal, or colonic erosions/ulcers. (can be confused w/ Crohn’s)
- CHEMO drugs: can cause lesions
- ABX: can result in pseudomembranous colitis, secondary to C. diff infection
A pt presents w/ chronic, relapsing abdominal pain, bloat & changed bowel habits w/ unknown etiology.
Endoscopic, colonoscopic and microscopic exams are normal.
IBS
Dx: clinical criteria, exclude organic causes
What factors contribute to IBS?
Colon transit rate changes
Excess bile
Enteric nervous system dysfunction
Immune activation or shift in microbiome
What is the Rome II diagnostic criteria for diagnosing IBS?
recurrent abd pain/discomfort >3 days/mo w/ 2+ of following
- Improvement w/ defecation
- Onset assoc. w/ change in frequency of stool
- Onset assoc. w/ change in form (appearance) of stool
What is sigmoid diverticulitis?
Increased intraluminal pressure → outpouchings at points where muscle is not continuous –>
Multiple inflamed diverticulae in the sigmoid colon → diverticulitis
A 63 y/o pt presents w/ lower abd discomfort, pain, and possible GI bleed.
- 50% of pts are over 60
- Pts are usually asymptomatic
Dx?
Tx?
Sigmoid Diverticulitis
Uncomplicated cases tx w/ clear diet, abx, & increased fiber
What are common complications of sigmoid diverticulitis?
- Inflammatory colitis in the affected sigmoid colon segment
- Perforation & abscess formation possible
- Complications> surgery
What is solitary rectal ulcer syndrome?
Malfuncitoning puborectalis→increased strain on defecation→rectal mucosal prolapse→ulceration + polypoid masses (inflammatory polyp) on anterior rectal wall
A young pt w/ bloody stool presents w/ pain on defecation and alternating constipation and diarrhea.
Dx?
Solitary Rectal Ulcer Syndrome
*can mimic adenocarcinoma or Crohns
What condition has fibromuscular hyperplasia of LP w/ inflammation and ulceration as well as reactive crypt hyperplasia?
Solitary Rectal Ulcer Syndrome
What are intestinal polyps?
Spontaneous or part of polypoisis syndrome
Inflamed, regenerating mucosa that projects above level of surrounding mucosa that is frequently ulcerated
Either:
- sessile
- pedunculated
What is the clinical significance of NON-neoplastic inflammatory polyp?
Assoc. w/ conditions like solitary rectal ulcer syndrome, ulcerative colitis & Crohn’s
• Occurs anywhere in GI tract
• In Ulcerative Collitis & Crohn’s Disease = “inflammatory psuedopolyps”
What the MC type of polyp in young children (but also seen in adults)
NON-neoplastic juvenile polyp AKA hamartomatous polyp
What are the two types of juvenile polyps?
- Sporadic → solitary polyp in colon (usually rectum)
2. Polyposis syndrome → multiple polyps in stomach, small bowel & colon (mut SMAD4> increased risk of adenocarincoma)
What percent of pts w/ juvenile polyposis syndrome may develop adenocarcinoma by age
45?
30-50%
What type of polyp appears rounded, smooth and unilobular w/ erythematous cap of eroded tissue?
classic juvenile polpy
What is Preutz Jeghers syndrome?
NON-neoplastic hamatomatous polyp
Pts present w/ multiple polyps and mucocutaneous hyperpigmentation
What is the MC site for PJ polyps?
small bowel> colon> stomach
PJ polyps that undergo STK11 loss of fxn mutation increase the risk of…
adenocarcinoma and other malignancies
What type of polyp is frequently peducnulated and has an aborizing smooth muscle pattern?
PJ polyp
What is the MC type of colonic polyp in adults?
NON-neoplastic Hyperplastic polyp
Where are hyperplastic polyps usually found?
LEFT colon esp rectum
What types of polyps contain glands that show serration in the mid portion?
Hyperplastic polyp
What is an adenoma?
BENIGN but can become malignant
Where are adenomas usually located?
COLON> small bowel (ampulla of d)
What type of polyp is characterized by dysplastic glandular proliferation?
ADenoma
If an adenoma has a high grade dysplasia it increases hte likelihood of…
adenocarcinoma
What are the two types of adenomas?
- tubular (tubular proliferation of glands)
2. Villous (more likely to contain adenocarcinoma)
What is sessile serrated syndrome?
Resembles hyperplastic polyps but LACKS adenomatous epithelium
HAS neoplastic potential
Where is sessile serrated syndrome usually located?
RIGHT colon
What accounts for 1% of CRC cases?
FAP
What causes FAP?
AD germline mut in APC (TSG)
A pt presents w/ a large number of adenomatous polyps in the colon and rectum in childhood/adolescence/early adulthood.
Dx?
Tx?
FAP
(>100 polyps)
Colectomy
FAP increases the risk for what type of cancer?
GI adenocarcinoma
How do Gardener’s syndrome and Turcot syndrome relate to FAP?
FAP variants w/ extra intestinal manifestations
What pts develop desmoid tumors, osteomas, epidermal cysts, dental abnormalities, and thyroid tumors?
Pts w/ Gardener’s syndrome
What is Turcot syndrome? What mutations are associated with that?
Coexistence of hereditary colon cancer syndrome along w/ CNS tumors
Some pts: APC mut → FAP → medulloblastoma (BRAIN)
Others: DNA mismatch mut → HNPCC → glioblastoma multiforme
What causes HPNCC (Lynch syndrome)?
AR MMR mut> microsatellite instability>
increased risk of malignant transformation
A pt presents before age 50 w/ multiple right sided colonic tumors as well as extra-colonic endometrial cancer.
Dx?
HPNCC
What is the MC location of adenocarcinoma?
50% in duodenum
What are RFs for small bowel adenocarcinoma?
FAP
Crohns disease (from dysplasia in the hileum)
Celiac disease
A pt presents w/ sxs of bowel obstruction, bleeding, intussusception, or perforation and has tumors @ ampulla → bile obstruction, pancreatitis, jaundice.
Dx?
Small bowel adenocarcinoma
What is the MC location for GI neuroendocrine tumors?
Ileum
Where is a sml bowel functional tumor located? What can it lead to?
Duodenal tumors: some secrete gastrin → Zollinger-Ellison syndrome
Where is a sml bowel non-functional tumor located? What can it lead to?
Jejunum & ileum: Often >2 cm w/ transmural invasion & metastasis
Carcinoid syndrome possible
A pt presents w/ crampy abdominal pain, nausea, vomiting and weight loss.
Non-functional tumor
What type of tumor presents as a bulky RIGHT sided high grade neuroendocrine carcinoma?
Colonic GI NE tumor (rare)
What NE tumor presents as polyps <1cm and has a favorable prognosis?
Rectal NE tumor
What NE tumor occurs at the tip of the appendix and leads to increased secretion of serotonin?
Appendix
Present in ALL ages
Asymptomatic and benign.
What is associated w/ the use of anthraceneline laxatives?
melanosis coli (brown mucosa and lipofuscin like pigment in mucosal mphages)
What is lymphomatosis polyposis?
small or large bowel lymphomas, usually B cell type.
Can be systemic or GI primary.
(Mantle cell lymphoma → lymphomatous polyposis)
What is acute appendicitis?
acute inflammation involving at least the muscularis propria
What is seen in severe cases of acute appendictis?
suppurative inflammation w/ gangrenous necrosis → perforation & suppurative peritonitis
What is the pathogensis of appendicitis?
Obstruction (fecalith [stone-like mass of hard stool] or lymphoid hyperplasia following viral infection) → Increased intraluminal pressure → compromised venous outflow →
ischemic injury & stasis of luminal contents → bacterial overgrowth → trigger acute inflammatory response w/ edema and neutrophilic infiltration
How does appendicitis appear grossly?
Thick purulent coating marked w/ hyperemia of serosa, increased appendix diameter
How does appendicitis appear micro?
massive inflammatory infiltrate, extensive ulceration & hemorrohage.
Island of heavily inflamed mucosa
A pt presents w/ periumbilical pain that localizes to RLQ, abd tenderness over McBruney’s pt and nauesea & vomiting following the abd pain.
Dx?
Acute appendicitis
MC in adolescents and young children
What labs are used to dx appendicitis?
elevated WBC and neutrophil
What imaging is used to dx appendicitis?
US- mucosal and submucosal walls have become discontinuous
CT- appendicolith, fluid inside appendix and free fluid
What complications are associated w/ appendicitis?
Perforation w/ perappendiceal abscess
Pyelophlebitis
Portal venous thrombosis
Liver abscess
Bacteremia, sepsis
Death
What are the two types of appendiceal carcinomas?
- Appendicular mucinous tumors
2. Signet ring adenocarcinoma
What constitutes the majority of appendix tumors?
Appendicular mucinous tumors
What are the different grades of Appendicular mucinous tumors?
Mucinous adenoma (mucinous cystadenomas) - confined to appendix, no high grade cytologic atypia or architectural complexity, and no invasion, often cystic (where it gets its name)
Low grade mucinous neoplasm – invasive, low grade cytology
Mucinous adenocarcinoma (invasive, high grade cytology)
What is signet ring adenocarcinoma?
can occur in the appendix (or stomach) and its rare
VERY aggressive tumor that looks like colonic adenoma
What is a pseudomyoxma peritonei?
presence of abundant mucinous material on the peritoneal surfaces
What causes a pseudomyoxma peritonei?
Almost all cases d/t appendiceal mucinous tumors
What is the pathology of pseudomyxoma peritonei?
Low grade mucinous adenocarcinoma – pools of mucin are acellualr or low, atypical cellularity
High grade mucinous adenocarcinoma – pools of mucin w/ high cellularity or high grade cytology
What are hemorrhoids?
ectasia of rectal venous plexus d/t elevated venous P
What are external hemorrhoids? and what causes them?
Straining at stool d/t constipation or venous stasis in pregnancy >
Dilation of superior rectal vessels BELOW the pectinate line
What hemorrhoids can prolapse out of hte rectum?
internal
A pt presents w/ rectal bleeding that is especially bright red on TP.
Dx?
Hemorrhoids
How do you tx hemorrhoids?
sclerotherapy
rubber band ligation
hemorrhoidectomy (severe)
What is an anal fissure?
linear separation of tissues of anal canal extending through mucosa
90% are posteriorly located and caused by firm BM
What is an anal fistula?
tract may lead to skin or end blindly in the perianal soft tissue
What are hte MC causes of anal fistula?
interspincteric abscess arising in anal duct d/t trauma, Crohn’s or UC
What is a rectal prolapse?
Associated w/ straining at stool >
intussusception of rectum through anus d/t weak rectal support
*Common in elderly
What is a condyloma accuminatum?
polypoid wart, HPV associated (STI)
papillary formations and acanthosis of the epithelium
What is an anal epithelial neoplasm?
premalignant squamous dysplasia of anal canal, HPV associated (STI)
What are the stages of AINs?
ANI – mild squamous dysplasia
ANII – moderate
ANIII – severe squamous dysplasia/ carcinoma in situ
How does AIN present in immunocompromised individuals?
invasive cancer
What type of neoplasm that is associated w/ HPV presents microscopically w/ thickened mucosa and an inflammatory lymphocytic infiltrate as well as atypia and increased mitotic activity?
AIN
What is hte MC type of anal carcinoma?
SCC
What is the primary RF for SCC?
HPV (esp type 16 and 18)
Where do anal carcinomas MC arise and how does this relate to LN drainage?
at the pectinate line>
dual LN drainage>
Rectal OR inguinal LN
A pt presents w/ anal bleeding, pain, a mass lesion, and pruritis.
Dx?
Anal carcinoma
HOw do you tx advanced stage anal carcinoma?
radiation and chemo
