Inflammatory Bowel Disease/Carcinoid, Gastrointestinal Stromal Tumor and Lymphoma Flashcards Preview

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Flashcards in Inflammatory Bowel Disease/Carcinoid, Gastrointestinal Stromal Tumor and Lymphoma Deck (45)

Inflammatory Bowel Disease

-group of chronic inflammatory conditions of colon and small intestine
-chronic relapsing immune activation and inflammation within the GI tract
-dysregulation of the immune response to GI luminal bacteria


2 major forms of IBD

1) Crohn Disease
2) Ulcerative Colitis


Environmental Risk Factors for IBD

-cigarette smoking (dec. UC, inc. CD)
-appendectomy (dec. UC, inc. CD)
-high-sanitation level in childhood (inc. CD)
-high-intake refined carbs (inc. CD)


"Hygiene Hypothesis"

--incidence of immune-mediated diseases rising in developed countries (related to modern hygiene or lack of exposure)
-Conflicting data in IBD (protective: exposure to pets), or maybe risk factor


Ulcerative Colitis

-chronic inflammatory disorder of the GI tract affecting the large bowel, relapsing
-begins in rectum and extends proximally continuously,no skin lesions
-rarely pericolonic abscess
-indolent, relapsing disease
-no skip lesions


Ulcerative Colitis: Endoscopically

-hyperemia, edema, granularity with friability, easy bleeding, broad based ulceration, pseudopolyps, tunnels with mucosal bridges, rarely perforation


Ulcerative Colitis: Toxic Megacolon

-shutdown of neuromuscular function secondary to exposure of fecal material to muscularis mucosae and neural plexus


Ulcerative Colitis: Gross Pathology

-edematous, congested and hemorrhagic mucosa with superficial ulceration and loss of normal folding pattern


Ulcerative Colitis: Microscopic Pathology

-edematous congested mucosa with more blue than normal = inflammatory cell nuclei, and with superficial ulceration
-cyrpt "abscesses"


Ulcerative Proctitis

-inflammation is confined to the rectum
-rectal bleeding may be the only sign
-rectal pain, feeling of urgency or an inability to move the bowels in spite of the urge to do so (tenesmus)
-this form of ulcerative colitis tends to be mildest



-involves rectum/sigmoid
-bloody diarrhea, abdominal cramps and pain and tenesmus are common


Left-sided colitis

-inflammation extends from rectum up the left side through the sigmoid and descending colon
-bloody diarrhea, abdominal cramping and pain on left side, and unintended weight loss



-entire colon
-bouts of bloody diarrhea that may be severe, abdominal cramps and pain, fatigue and significant weight loss


Fulminant Colitis

-uncommon, life-threatening
-entire colon
-severe pain, profuse diarrhea, dehydration and shock, SIRS
-extensive and deep colonic injury


Barium Contrast Studies

-superb instrument to observe fine mucosal detail
-dependent on skill of radiologist
-requires appropriate use of barium, air insufflation, palpation, positioning, compression and use of spot films


Ulcerative Colitis: CT

-increasing use in diagnosis
-most sensitive for evaluation of free air (toxic megacolon with perforation)
-See liver, mesenteric inflammation & lymphadenopathy
-CT dosen't show mucosal detail well (may miss subtle changes early in disease that can be seen with air contrast BE and endoscopy


Crohn's Disease

-involves any location of GI tract
-propensity for distal small bowel & proximal colon
-can involve mouth to anus: apthoid ulcers in mouth, esophageal ulcers, gastric disease, small bowel


Main location for Crohn's?

small intestine alone (30%)
small intestine + colon (40%)
colon alone (40%)


Peak age for Crohn's?



Crohn's Colitis

1. asymmetrical disease where there is involvement
2. aphthous ulcers
3. rectal sparing
4. skin lesions
5. deep ulcerations
6. stricture formation
7. fistula
8. disease can be limited to right colon


Characteristics of Crohn's?

1. transmural involvement
2. noncaseating granuloma (40-60%)
3. Fissuring with fistula
4. Skip lesions


Crohn's Disease: Gross Pathology

-"cobblestone" mucosa
-"skip lesions" alternating areas of involved and uninvolved bowel
-"creeping fat" on the serosa extending to seal off areas of transmural inflammation


Crohn's Disease: Microscopic Pathology

-edema, inflammation w/neutrophils, lymphocytes, plasma cells, eosinophils & macrophages, forming granulomas (35%)
-rarely necrotizing, not as tightly cohesive as sarcoidosis


Endoscopy in Crohn's Disease



Gastric & Duodenal Crohn's

-gastric ulcers
-crohn disease in distal antrum & duodenal bulb


Crohn's Disease: Radiology

mucosal hyperenhancement and mesenteric hypervascularity


Erythema Nodosum: microscopic pathology

-type of panniculitis (inflammation of subcutaneous tissue) with lymphocytes, macrophages and multinucleated giant cells, leading to fibroblastic repair response and fibrosis


Pathophysiology of Gastric Carcinoid Tumors

-chronic gastritis or gastric acid suppression
-hypergastrinemia compensatory response
-gastric diffuse neuroendocrine hyperplasia

-comes from neuroendocrine cells


Gastric Neuroendocrine Tumor (Carcinoid) Immunostain

+ for chromogranin


Gastric Neuroendocrine Tumor

-80% associated with hypergastrinemia, indolent, metastases uncommon (can remove antrum)
-20% not associated with hypergastrinemia, aggressive, many with metastases at diagnosis, associated with carcinoid syndrome


Zollinger-Ellison Syndrome: diagnosis

-fasting gastrin level >1000 pg/ml with gastric pH below 5
-secretin stimulation test (gastrin levels 0, 2, 5, 10, 15, 20 min after IV secretin)
-increase in gastrin of >200 pg/ml (100% specific)


Treatment of Zollinger-Ellison Syndrome

-surgical resection: solitary, non-metastatic disease
-medical management: high dose PPI, long asting somatostatin analog
-Metastatic disease: streptozocin/doxorubicin or temozolamide
-resection, TACE, RFA, OLT


Intestinal Neuroendocrine Tumor (Carcinoid)

-typically late middle-age
-ileum & appendix = common
-multiple sites
-abdominal pain = most frequent symptom
-intermittent obstruction can occur
-most common neoplasm in appendix (1 in 300 appendectomies)
-rectal tumors small, rarely metastatic


Carcinoid Syndrome

-episodes of flushing (95%), diarrhea, wheezing, colicky abdominal pain
-right heart endocardial fibrosis (50%)
-10% liver metastases (ileal tumors)
-due to vasoactive polypepptides, serotonin
-high urine 5-hydroxyindole acetic acid (5-HIAA) diagnositc (but limited sen & spec)


Colorectal Neuroendocrine Tumors

Colon: more in right colon, usually large mass
Rectum: found incidentally, carcinoid syndrome is rare, prognosis depends on size


Gastrointestinal Stromal Tumors (GIST)

-uncommon (5,000/yr in US), older adults
-most common in stomach and small intestine
-derive from or differentaited toward interstitial cells of Cajal, GI pacemaker cells that form the interface b/w autonomic innervation & smooth muscle cells of gut
-most have mutation in KIT transmembrane receptor tyrosine kinase, activating it as an oncogene, with positive immunostain for CD117
-all possibly malignant or malignant


GI stromal Tumors (GIST) Presentation

40% with overt GI bleeding
40% with abdominal mass
20% abdominal pain


GIST Detection

CT detects, but endoscopy biopsy can be false - b/c they are in the wall, not mucosa
-Endoscopic ultrasound-guided fine needle aspiration has 82% sen and 100% spec


GIST treatment

surgery, if metastatic, can usually be given tyrosine kinase inhibitor imatinib mesylate


Post-Transplant Lymphoproliferative Disorder

-Immunosuppression can allow B cells infected with Epstein-Barr virus to proliferate in an uncontrolled manner
-Blood test for EBV DNA can detect it
-If immunosuppression can be safely decreased, sometimes the proliferation will come under control


Gastrointestinal Lymphoma

-Rare ( most of the rest aggressive diffuse large B-cell lymphomas


GI Lymphoma Presentation

-epigastric pain (93%)
-anorexia (47%)
-weight loss (25%)
-occult bleeding (19%)
-nausea/vomiting (18%)


GI lymphoma diagnosis

endoscopy with biopsy


GI lymphoma treatment

antibiotics for MALToma
radiation/chemo for other types


GI lymphoma prognosis

good for MALToma
bad for other types