Lecture Review Flashcards
What parasite is this image associated with?
Babesia
(presence of tetrad)
What specific parasite is this associated with?
Plasmodium Falciparum
(Banana gametocyte)
ID the parasite this image is associated with
Acid fast of Cryptosporidium oocysts
ID the parasite this image is associated with
Fluoresence of Cryptosporidium Oocysts
What parasite is this?
Giardia
What organism is this associated with?
This is a cyst for Giardia
Trichomonas Vaginalis
What is this and what is it associated with?
Amastigote
Intracellular form of Leishmania/Trypanosomiasis found in human
This is the result of what?
Cutaneous Leishmaniasis
What is this from?
DFA (fluoresence) of Pneumocystis Jiroveci (Carinii)
What is this?
Silver Stain of Pneumocystis Jiroveci (Carinii). Shows empty cysts which have expelled the protozoa.
Interpret this Serology:
HBsAg: negative
anti-HBc: negative
anti-HBs: negative
Susceptible
Interpret this Serology:
HBsAg: negative
anti-HBc: positive
anti-HBs: positive
Immune due to natural infection
Interpret this Serology:
HBsAg: negative
anti-HBc: negative
anti-HBs: positive
Immune due to hepatitis B vaccination
Interpret this Serology:
HBsAg: positive
anti-HBc: positve
IgM anti-HBc: positive
anti-HBs: negative
Acutely infected
Interpret this Serology:
HBsAg: positive
anti-HBc: positve
IgM anti-HBc: negative
anti-HBs: negative
Chronically infected
Interpret this Serology:
HBsAg: negative
anti-HBc: positve
anti-HBs: negative
Interpretation unclear! (4 possibilities)
- Resolved infection (most common)
- False positive anti-HBc (thus susceptible)
- “Low level” chronic infection
- Resolving acute infection
What liver disease is this associated with?
(hint: these are plasma cells)
What else might you see?
Autoimmune hepatitis
This image shows plasma cells creeping into the lobule. You would also expect to see interface hepatitis.
Positive blue staining for iron in liver as in the image, is indicative of what disease process?
Hemochromatosis
A disease of iron overload
What is the phenomenom in the bottom left photo called and what is it associated with?
“Scalloped edges”
Celiac Disease
What is pyloric stenosis and what are its symptoms (3)?
Congenital hypertrophy of the smooth muscle of the pylorus
Sx: projectile vomiting in first 2-6 weeks of life, visible peristalsis, olive-like mass in abdomen.
What is the most likely cause for acute gastritis? chronic?
acute: impairment of protective system (via NSAIDs, direct injury, ingestion, etc.)
chronic: H. Pylori
What stains are useful for highlighting H. pylori (2)?
- methylene blue stain
- Warthrin-starry stain
Describe the pathogenesis of Autoimmune chronic gastritis and what occurs as a result.
Is the risk of adenocarcinoma affected?
- There are antibodies to parietal cells and IF
- Antrum is spared
- Results in B12 deficiency (IF loss) and resulting anemia
- Also decreased pepsinogen (acid) levels (chief cells loss)
- Increased risk of gastric adenocarcinoma
What are the symptoms and acute PUD?
Chronic?
Describe the ulcers in each case.
Acute:
- N/V w/ coffee-ground hematemesis
- Ulcers: <1cm and sharply demarcated
Chronic:
- Epigastric burning or aching that is worse at night
- Relieved w/ akali or food
- Nausea, bloating, belching
- Could be caused by ZE
- Ulcers: Usually solitary and sharply punched out
What is the relationship between location and prognosis for a carcinoid tumor?
What kind of tissue do these tumors arise from?
These tumors arise from neuroendocrine organs (G-cells of stomach)
Location determines prognosis:
- Foregut is resectable
- Midgut is most aggresive
- Can also be located in the hindgut
Gastrointestinal Stromal Tumor (GIST)
Pathogenesis?
What does it look like?
Treatment?
- Mesenchymal neoplasm of interstitial cells of cajal
- 75-80% w/ GOF mutation in gene encoding tyrosine kinase c-KIT
- Solitary, well circumscribed, fleshy, submucosal mass
- Tx: Surgical resection (if possible); Imatinib (there is often resistance)
What are the (3) general causes for Gastric Adenocarcinoma?
- H. Pylori
- EBV
- Mutation
Describe the (2) types of mutation which can lead to Gastric Adenocarcinoma.
What are the mutations?
What type of adenocarcinoma do they cause?
What are the differences in the tumor types and sexes affected?
Other key points w/ treatment and clinical findings?
Diffuse Type
- Caused by mutation of CHD1 causing E-cadherin fxn loss
- Infiltrative growth and discohesive cells w/ large mucin vacuoles (signet ring cells)
- Equal incidence between men and women
- Linitis plastica (thick stomach wall)
Intestinal type
- Familial APC mutations
- Bulky, glandular, exophytic mass or ulcerated tumor
- Men twice as common
- Tx: Surgical resection (chemo is not effective)
*
Intestinal type M__etastatic Gastric Adenocarcinoma is called what and is located where?
Diffuse type?
Intestinal: Sistery Mary Joseph nodule- Mets to Periumbilical region
Diffues: Krukenberg tumor- Mets to Bilateral ovaries
What type of muscle makes up the upper 2/3rds of the esophagus? lower 1/3rd?
Striated = upper
smooth= lower
What is achlasia and what is one of the key secondary etiologies?
Pathogenesis?
How does it look on barium swallow?
- Incomplete relaxation of LES and disordered motility of the esophagus (anti-peristalsis); Esophageal dilatation
- Pathogenesis: destruction of myenteric plexus
- Birds beak deformity on barium swallow
Associated w/ Chagas disease
Boerhaave syndrome
What is it and what is a key finding associated?
Transmural esophageal rupture from severe vomiting
Very high morbidity/mortality, so always a medical emergency
Associated with Subcutaneous emphysema of skin (rice krispy feeling when you press on patient’s skin)
What are the (3) M’s of Herpes Simplex virus associated with one of the forms of esophagitis?
Multinucleation, Molding and Margination
All forms of Esophagitis show what (3) histologic changes?
- Basal layer hyperplasia (>20% of mucosal thickness)
- Lamina Propria papillae which reach top 1/3rd of mucosa
- Intra-epithelial eosinophils
Name the corresponding LNs that SCC in each of the following parts of the esophagus spreads to:
Upper 1/3rd
Middle 1/3rd
Lower 1/3rd
Upper: Cervical LNs
Middle: Mediastinal/ tracheobronchial LNs
Lower: Celiac/gastric LNs
Name the Vibrio Cholerae exotoxin responsible for causing disease.
AB Type ADP-ribosylating toxin
What level of inoculum is needed for a campylobacter infection?
Low! As low as 500 organisms
Clinical manifestation of Campylobacter Jejuni
What disease is it affliated with?
Fever (1 day) followed by sever abdominal pain and diarrhea w/ blood, pus and campy in feces
Associated w/ Guillain-Barre Syndrome (ascending paralysis)
What are the roles of Bab A, Vac A and Cag A, in h.pylori infection?
Bab A: Used for adherence. Binds to lewis blood group antigens
Vac A: Vacualiting cytotoxin that inserts into epithelial cell membranes forming nutrient releasing poor. Also inserts into mitochondria to release cytochrome C and induce apoptosis.
Cag A: Functions to promote cytokine production
Volvulus
Where does it tend to happen for children? adults?
Twisting of the bowel around its mesentery. Leads to obstruction and infarction.
Tends to be midgut for children and sigmoid for adults.
Meckel’s diverticulum
Persistence of the omphalomesenteric duct.
Known as the disease of “2’s”
(2% of pop.; 2x likely for men; 2 main complications- pain w/ inflammation and hemorrhage w/ ulcer)
Hirschsprung Disease
Form of megacolon in which the absence of ganglion cells (enteric neurons) leads to premature death of neural crest cells migrating from cecum to rectum. Mostly in males.
What effect does pancreatic insufficiency have on neutral fat? D-xylose absorption test?
- Increased neutral fat
- Normal D-xylose absorption test (urinary excretion)
Abetalipoproteinemia
Decreased synthesis of apo B which results in decreased ability to generate chylomicrons.
What is the skin issue associated with Celiac disease? How do we diagnose this disease (be specific)?
- Dermatitis herpetimormis (skin blistering disease)
- Diagnosis via:
- Biopsy: Villous atrophy w/ inc. intraepithelial lymphocytes (CD8)
- Serotype: anti-TTG, anti-deaminated gliadin, anti-endomysial antibodies (If pts are IgA deficienct, IgG tests are needed)
Both collagenous and lymphocytic colitis cause what clinical presentation?
Chronic watery diarrhea (3-20 non-bloody stools per day)
What is the pathogenesis and clinical presentation in whipple disease?
Pathogenesis: Tropheryma whippleli bug is engulfed by macrophages
Sx: Malabsorption, lymphadenopathy (due to congestion of lymph vessels w/ macrophages), and arthritis
What are the key differences between Crohn’s Disease and Ulcerative Colitis, in terms of…
Pt. Demographic? Location? Gross mrophology? Microscopic changes? Complications? Intestinal Manifestation? Key Extraintestinal manifestations?
Crohn’s: White Jewish folks, with non-bloody diarrhea, cobblestoning, skip lesions throughout GI tract, and strictures
UC: Wealthy western folks, with bloody diarrhea, pseudopolyps limited to the colon, and megacolon
Juvenile polyps and malignancy
Mostly occur sporadically in rectum of children < 5y/o
If single, no malignant potential.
If multiple, increased risk of adenocarcinoma.
Hamatomatous (Peutz-Jeghers syndrome)
Pathophysiology? Presentation? Malignant potential?
- Multiple non-malignant hamartomas throughout the GI tract
- Sx: Hyperpigmented melanotic macules of mouth, lips, genatalia and hands
- Increased CRC risk (although the polyps themselves have NO malignant potential)
What are adenomatous polyps and what are they precursors to? What are the different types (2) and which is more likely to be dangerous?
These are benign polyps that are precursors to the majority of colorectal adenocarcinomas.
There are peduculated types and sessile types. Sessile is more likely to grow to cancer.
Where do sessile serrated adenoma occur? What is the main mechanism for their pathogenesis?
Right colon
DNA mismatch repair
Familial Adenomatous Polyposis
What is it and what does it lead to? What causes it?
It is a condition in which patients develop 100-1000 polyps, due to an autosomal dominant defect in the APC gene (Ch5q21)
100% development into colorectal adenocarcinoma
What are the (2) variants of FAP? Describe them.
Gardner syndrome- same as FAP + osteomas (mandible, skull, and longbones), epidermal cysts, desmoid and thyroid tumors, and dental abnormalities
Turcots syndrome- Intestinal adenomas + tumors of CNS which depend on the the type of mutation (APC: medulloblastoma/ repair mutation: glioblastoma)
Hereditary nonpolyposis colorectal cancer (Lynch syndrome)
What is it and what causes it?
Associated w/ FAP but fewer number of polyps. Cancer occurs at a younger age than sporodic cancers.
Caused by mutation in DNA mismatch repair genes
What are the (2) main molecular pathways to CRC and what specific conditions are they each associated with?
- APC/WNT pathway: APC is a neg. regulator of Beta-Catenin. Double knockout of APC increases B-catenin, which translocates to the nucleus and activates transcription of MYC, Cyclin D1, etc. Associated w/ FAP and sporodic colon cancer.
- DNA Mismatch Repair: spelling error in coding region. Affect on MLH, MSH, and PMS genes. Associated w/ HNPCC
Right sided vs Left sided CRC
Right: asymptomatic for longer because colon diameter is larger. First symptom for right side is anemia due to blood loss/ulceration
Left: smaller diameter so obstruction occurs much quicker (changes in BM habits). Tend to see napkin ring lesion.
What cancer type is most commonly found in the rectum? The anus?
Rectum: adenocarcinoma
Anus: SCC
Name/describe the (3) Neoplasm types associated w/ the appendix
- Mucocele: benign dilatation o lumen by mucinous secretion
- Mucinous cystadenoma: proliferation of benign neoplastic cells and dilation which may rupture
- Mucinous cystadenocarcinoma- invasion of neoplastic cells
Pseudomyxoma peritonei
Distention of peritoneal cavity by the presence of semisolid mucin and epithelial mucin producing implants and/or malignant cells. Possible complication of mucinous tumor of the appendix.
What separates the upper GI system from the lower GI system?
Ligament of Triez
Hematochezia
Bright Red Blood Per Rectum (BRBPR)
Usually denotes LGI bleed but could also be UGI bleed
What are the top (4) differentials for an UGI bleed?
- PUD
- Esophageal varices
- Erosive esophagitis
- Mallory-Weiss tears