GI Pathology: Small Intestine, Appendix, and Peritoneum Flashcards
Describe the attached photo?
Small Intestine: Normal History
it is normal to have some lymphocytes & plasma cellsm in the lamina propria– it is not normal to have a lot
it is not normal to have PMNs in the epithelium
Describe the provided image?
Meckel Diverticulum
outpouching of the small intestine that contains all the layers of the small intestine wall
What is the “rule of twos” for meckel diverticulum?
- about 2 inches in length
- usually within 2 feet of ileocecal valve
- Affect about 2% of the population
- Two types of heterotopic tissues are commonly present
- gastric
- pancreatic
- 2X more common in males than females
Identify the 4 major causes of intestinal ostruction
Identify the stucture in the following image?
Incarcerated Hernia
this is when the outpouching swells and it is impossible to get back in
Identify the stucture in the provided image
most common cause of obstruction in the united states
caused by intradominal inflammtion
What is an intussusception?
- one segment of the intestine, constricted by a wave of peristalsis, suddenly becomes telescoped into the immediately distal segment of bowel
- adults: tumors
- kids: viral (adnovirus, rotavirus vaccine)
Identify the structure presented in the image?
Intussesception
Identify the structure presented in the image
Ischemic Bowel Disease: segmental infarction
identify the different types of ischemic bowel disease?
causes are going to be anything that causes obstruction of blood vessels
Identify the structure presented in the image?
Ischemic Bowel idsease: Global
any time there is a systemic problem of low fluid state
catastrophic event
The provided images are microscopic examples of what featue?
Ischemic bowel
heart attack of the bowel
organizing thormbus is the dark circular section
Describe neonatal necrotizing enterocolitis.
Most common demographic?
Pathogenesis?
Apearance?
- demographics
- premature
- any part of small or large intestine
- TI, cecum, right colon more common
- pathogenesis
- multi-factorial
- genetic predisposition
- immature GIT
- initiation of oral feeding
- bacterial colonization
- intestinal ischemia
- mucosal injury
- x-ray: pneumonatosis intestinalis
- gross: distended, grey-purple, gas bubbles
- micro: ischemic necrosis, bacteria, gas bubbles
- high perinatal mortality
- multi-factorial
What are the types of malabrosption syndromes?
Sympoms?
Common diseases?
- Types (impaired absorption)
- luminal brush border processing
- absorption into intestinal mucosa
- trasnport into circulation
- symptoms
- chronic diarrhea (relieved with fasting)
- steatorrhea
- flatulence
- vitamin/mineral deficiencies
- abdominla pain/ distension
- muscle wasting
- weight loss
- dieseases
- common in US
- celiac disease (celiac sprue)
- pancreatic insufficiency
- chron disease
- others
- tropical sprue
- whipple disease
- cystic fibrosis
- abetalipoproteinemia
- common in US
Describe the antibody and cell mediated injury associated with celiac disease.
Histologic sequelae?
- Antibody/cell mediated injury
- Gluten is converted to Gliadin
- gliadin induces IL-15 expression by epithelial cells
- IL-15 activatees proliferation fo CD8+ T-cells in intestinal epithelium
- epithelial damage
- gliadin peptides leak into lamina propria and are deaminated by tissue trasnglutaminase and interact with HLA-DQ2 or DQ8 on APCs
- APCs stimulate CD4+ T-cells to produce cytokines (contribute to tissue damage)
- B-cell response with antibody production
- gliadin induces IL-15 expression by epithelial cells
- Gluten is converted to Gliadin
- Histologic sequelae
- increased intraepithelial lymphocytes
- villous blunting
- crypt elongation
What is Celiac disease?
Demographic?
symptoms?
- Immune-mediated enteropathy triggered by ingestion of gluten-containing foods in genetically predisposed individuals
- Demographics
- presents in infancy up to 30-60 years
- typically caucasians of european descent
- Symptoms
- chronic diarrhea
- bloating
- fatigue
- weight loss
- failure to thrive (pediatric)
- symptoms of malabsorption
- asymptomatic
What is shown in the provided images?
What are the criteria for diagnosis of celiac disease?
- Clinical documentation malabsorption
- small bowel biopsy – proven lesion
- circulating disease related antibodies in serum
- IgA against
- antigliadin - sensitive
- antiendomysial - sensitive & specific (difficult)
- anti-tissue transglutaminase - sensitive & specific (easier)
- anti-deamidated gliadin
- if IgA deficient (more common in celiac patients)
- anti-deaminated gliadin peptides IgG,
- anti-TtG IgG (less sensitive and specific than Anti-DAG IgG)
- IgA against
- uniequivocal improvemetn of sumptoms and mucosal histology on gluten withdrawl from diet
- +/- HLADQ2 or HLADA8
Celiac diseas is associated with what other heath indications?
- IgA deficiency
- other autoimune conditions (Type I DM)
- Down syndrome
- Dermatitis herpetiformis
- Enteropathy associated T-cell lymphoma
- Possibly higher incidence of small intestinal adenocarcinoma (controversial)
What is the pruritic blisterin skin disorder seen in 10% of patients with celiac disease?
Why does this happen?
Dermatitis herpetiformis
- seen in 10% patients with celiac disease
- IgA antibodies cross react with epidermal tissue transglutaminase
- subepidermal blister with neutrophilic microabcesses at tips of the dermal papillae
- granular IgA on DIF
What is shown in the provided images?
Person has Celiac disease
Agressive & rare
seen almost exclusively in patients with Celiac disease
What is Tropical Sprue?
Where is is most common?
How is it treated?
- histology similar to celiac diseases, except is worst in distal small bowel – etiologic agent is unknown
- NO association with DH
- NO significant risk of intestinal lymphoma or carcinoma
- tropical climates
- treat with broad-spectrum antibiotics
What is whipple disease?
Etiological cause?
Symptoms?
- Rare, systemic chronic disease
- MF, 10:1
- Caused by Tropheryma whippelii
- Clinical symptoms
- malabsorption, with diarrhea
- lymphadenopathy
- arthritis
- +/- neuropsychiatric manifestations
- Images
- laminia propria is chalked full of stuff
- with abundant clear cytoplastm– machrophages have engulfe organisms
What is shown in the provided images?
seen almost exclusively with immunocompromised patients
What are the different types of tumors of the small bowel?
- Epithelial
- adenomas- rare in small bowel
- adenocarcinomas- rare in small bowel
- Mesenchymal
- GIST- uncommon in small bowel
- leiomyomas and leiomyosarcomas
- Lymphomas
- MALT
- most common SI lymphoma in Wesern countries
- Enteropathy associated with T-cell lymphoma
- celiad disease
- Burkitt
- ileum/ileocecal region
- “starry-sky” pattern on histology
- MALT
- Neuroendocrine tumors (NET)- Most GI NETS arise in the small bowel
Where do GI neuroendocrin tumors origniate from?
Range of classification?
Tumor products/composition?
- Arise from GI mucosal endocrine cells
- From well differentiated neuroendocrine tumors (G1, G2, G3) to reuroendocrine carcinomas (small cell carcinoma and large cell neuroendocrine carcinoma)
- 1/3 SI tumors
- From well differentiated neuroendocrine tumors (G1, G2, G3) to reuroendocrine carcinomas (small cell carcinoma and large cell neuroendocrine carcinoma)
- Tumor products
- gastrin
- somatostatin
- serotinin
- urine metabolite: 5-hydroxyindolacetic acid
- nothing/non-functional
- Immunohistochemistry
- positive: chromogranin, synaptophysin, CDX-2, various hormones
- low grade malignant neoplasms
- slow growth, but highly invasive
- metastases
- regional nodes, liver, bone, skin, viscera
GI neuroendocrine tumor prognosis?
treatment?
- prognosis
- location is the most important prognostic factor
- foregut (stomach, duodenum, esophagus)
- rarely metastasize
-
midegut (jejunum ileum)
- aggressive
- hindgut (appendix, colorectal)
- often an inciental finding & uncommonly metastasize
- foregut (stomach, duodenum, esophagus)
- overall 5 years 50-65%
- confined to SI wall- 85%
- invasion of serosa- 5%
- location is the most important prognostic factor
- Treatment
- wide surgical removal of primary tumor, regional nodes, isolated liver mets
What are the clinical features of carcinoid syndrome?
What is it?
- Caused by vasoactive substances secreted by tumor into systemic circulation
- typically implies metastatic disease to liver
- occurs in <10% patients with neuroendocrine tumors
- Clinical features
- skin: flushing, cyanosis, dermal sclerosis
- GI: secretory diarrhea, abdominla cramps, nausea/vomiting
- Cardiorespiratory: bronchoconstriction, right side valve fibrosclerosi, heart palpations, intermittent hypertension
- Treatment
- somatostatin analogue
What is shown in the provided image?
classic neuorendocrine tumor
salt and pepper chromatin
What is shown in the provided image?
What is shown in the provided images?
Healthy appendix
What is the difference between the two photos presented?
normal is very shiny serosal surface
appendicitis, serosa is rough & red & puffy
What is shown in the provided images?
Acute appendicitis
need PMN in the gland
What are the types of appendiceal tumors?
- Well differentiated neuroendocrine (carcinoid) tumors
- most common tumor of the appendix
- often incidental and uncommonly metastasize
- ofen occur and the tip of the appenxi
- Mucinous Tumors of the appendix
- may cause a “mucocele”
- confined to appendix
- Low grade amn
- high grade amn
- invasion of appendiceal wall is definitely demonstrated
- mucinous adenocarcinoma
- risk for pseudomyxoma peritonei
What is shown in the provided image?
What is shown in the provided images?
What are the most common features of tumors of the peritoneum?
- most are malignant
- primary tumors are uncommon
- mesothelioma
- associated with asbestos exposure
- mesothelioma
- secondary tumors are common
- direct spread or metastatic seeding
- primary tumors are uncommon
- Tumors metastatic to peritoneum
- most common tumors producign diffuse serosal implants
- ovarian carcinoma
- pancreatic adenocarcinoma
- mucinous carcinomas may produce pseudomyxoma peritonei
- 95% arise from appendiceal mucinous tumors
- 5% are of ovarian or pancreatic origin
- most common tumors producign diffuse serosal implants
What is shown in the provied images?
Describe the features of the primary peritonela mesothelioma
What is shown in the provided images?
Pseudomyxoma peritonei
