GI Pathology Flashcards
What is Sialadenitis?
inflammation of a salivary gland. It may be subdivided temporally into acute, chronic and recurrent forms.
What are the causes of sialadenitis?
Infectious (viral - mainly parotids- and bacterial, mainly submandibular) and
non-infectious (Sjogren syndrome, sarcoidosis, radiation)
What is the most common pathogen in bacterially-related sialadenitis? Viral?
Staph aureus (and strep viridans)
Viral: mumps
Describe acute sialadenitis
It typically affects the parotid gland, causing the gland to become swollen and painful. Purulent discharge drains from the duct
Describe chronic sialadenitis
This usually occurs secondary to recurrent or persistent ductal obstruction due to a stone (sialolithiasis) resulting in episodic pain and swelling, usually at mealtime
◦Submandibular involvement may include persistent enlargement
What is this?
Oral hairy leukoplakia- This pathology is associated with Epstein-Barr virus (EBV) and occurs mostly in people with HIV, both immunocompromised and immunocompetent, albeit it can affect patients who are HIV negative
It most often occurs on the lateral aspect of the tongue, and, unlike thrush, it can not be scraped off
How does OHL appear histologically?
- Hyperkeratosis (gives it the white appearance)
- Acanthosis
- “balloon” cells in the upper spinous layer
Define leukoplakia
“a white patch or plaque that cannot be scraped off and cannot be characterized clinically or pathologically as any other disease.” (a diagnosis of exclusion)
Note that leukoplakia is considered premalignant until proven otherwise (even though only 5-25% actually are)
What pts. does oral leukoplakia most commonly occur in?
smokers and those who use chewing tobacco
Typically males, aged 40-70
What is the prognosis for oral leukoplakia?
Leukoplakia is a premalignant lesion. The chance of transformation into oral SSC varies from almost 0% to about 20%, and this may occur over 1 – 30 years. The vast majority of oral leukoplakias will not turn malignant, however some subtypes hold greater risk than others.
No interventions have been proven to reduce the risk of cancer developing in an area of leukoplakia, but people are generally advised to stop smoking and limit alcohol consumption to reduce their risk.
Where are some other places besides the mouth that leukoplakia can occur?
- esophagus
- bladder
- penis, vulva, vagina, or cervix
What are aphthous ulcers (canker sores)?
Superficial mucosal ulcerations more common in younger pts. that typically resolve within 7-10 days
What factors are associated with herpes reactivation?
trauma, allergies, UV light (sunburn), URTIs, immunosupression, stress, etc.
Describe the histology of herpes
Molding, Multinucleation, and Eosinophilic Inclusions
What are the three major types of oral candidiasis?
- pseudomembranous (thrush)
- eryhtematous
- hyperplastic
How does oral candida present?
Superficial, curdlike, gray to white inflammatory membranes composed of matted organisms enmeshed in an exudate that can be esily scrapped off to reveal and underlying erythematous base.
Describe fibromas of the oral cavity
These are modular fibrous tissue masses that are formed when chronic irritation results in reactive CT hyperplasia, most commonly occuring on the buccal mucosa along the bite line
What are oral pyogenic granulomas?
oral masses usually found on the gingiva of children, young adults, and pregnant women. These lesions are highly vascular and often erythematous appearing.
These tend to grow fastly but are typically benign and surgical excision is curative
What is erythroplakia?
red, velvety, possibly eroded areas that are flat or depressed relative to surrounding mucosa that are less common than leukoplakia, but are associated with a much greater risk of meligant transformation to OSCC
Approximately 95% of cancers of the head and neck are________
squamous cell carcinomas (SCCs). With the remainder being largely adenocarcinomas of salivary glands
Head and neck cancers have a BAD prognosis (Typically advanced stage when diagnosed; not amenable to screening)
In the oropharynx (but not the oral cavity), as many as 70% of SCCs, particularly those involving the tonsils, the base of the tongue, and the pharynx, harbor oncogenic variants of ______
HPV, particularly HPV-16. Those with HPV positive cancers have greater long term survival.
Oral SCCs
Multiple primary tumors may be present at initial diagnosis but more often are detected later, and tend to develop at a risk of 3-7%/yr. Note that the development of secondary primary tumors is a particularly poor prognosis and typically leads to death (survellance is important!)
How do OSCCs arise?
Two distinct pathways:
1) chronic alcohol or tobacco users typically produce tumors arising from mutations in TP53, p63, and NOTCH1
2) tumors arising in the tonsillar crypts or the base of the tongue related to HPV variants, particularly HPV-16 (most commonly overexpression of p16, a cyclin-dependent kinase inhibitor)
T or F. The prognosis of HPV-positive OSCCs is better than for HPV-negative tumors
T.
What are the most common locations for an OSCC to arise?
can arise anywhere but most commonly on the ventral surface of the tongie, the floor of the mouth, lower lips, the soft palate, and gingiva
OSCC
OSCC
Note that OSCC develop from dysplastic precursor lesions
How do OSCCs progress?
typically, they infiltrate locally before they MET (most commonly to cervical lymph nodes)
What drugs can produce xerostomia?
anticholinergic (salivation is parasympathetically driven!)
-antidepressants/antipsychotics
diuretics
AntiHTNs
more
What is the most common cause of viral sialadenitis?
Mumps (paramyxovirus), which primarily affects the parotids
What is a mucocele?
The most common inflammatory lesion of the salivary glands, resulting from either blockage or rupture of a salivary gland duct, with consequent leakage of saliva into the surrounding CT stroma
Note that it typically presents as a swelling of the lower lip that may change in size, particularly around meals
What pts do mucoceles most commonly occur in?
toddlers, young adults, and the elderly
What is Sialolithiasis?
obstruction of a salivary gland by stones- dehydration and decreased secretory function may predispose to infection
What is the most common salivary gland for a tumor to arise?
parotid (65-80%)
T or F. The likelihoof that a salivary gland tumor is malignant is inversely proportional to the size of the gland (roughly)
T. Up to 70-90% of sublingual (the smallest) gland tumors are malignant while only 15-30% of parotid tumors are
When do slivary gland tumors most commonlu occur?
usually in adults (but can occur in children)
What are the most common BENIGN salivary tumors?
pleomorphic adenomas (50%)
Warthin tumor (5%)
What are the most common MALIGNANT salivary tumors?
Mucoepidermoid carcinomas (15%)
Acinic cell carcinomas of adenocarcinoma NOS (6% each)
Describe pleomorphic adenomas
These are painless, slow-growing mobile masses found in the parotids mostly that are composed of a mixture of both epithelial and myoepithelial cells (aka mixed tumor)
What mutations are common in pleomorphic adenomas?
overexpression of PLAG1
What is the prognosis of pleomorphic adenomas?
These tend to recur is incompletely excised and CAN transform into a malignant mixed tumor (transformation increases with time from 2% at 5 yrs to about 15% at 15 yrs). If they do turn malignant, they have a very poor prognosis
Notice how pleomorphic adenomas are typically rounded, partially encapsulated, and where unencapsulated have protrusions into surround tissue
What are dentigerous cysts?
These are epithelium-lined cysts that originate around the crown of an unerupted tooth due to degeneration of the dental follicle most commonly seen with impacted third molars (wisdom teeth)
How do dentigerous cysts appear histologically?
They are lined by a thin, stratified squamous epithelium that typically is associated with a dense chronic inflammatory infiltrate within the underlying CT
T or F. Complete removal of a dentigerous cyst is curative
T.
What is an association of dentigerous cysts?
ameloblastoma – locally invasive tumors in the mandible, radiolucent “soap bubble”
What are odontogenic keratocysts?
(Now called keratocystic odontogenic tumor). These can occur at any age but most frequent in persons 10-40, have a male prodminance, and typically are located within the posterior mandible
These are highly locally agressive and have a high recurrence rate
How do OKCs appear histologically?
Histologically, the cyst lining consists of a thin layer of keratinized stratified squamous epithelium with a prominent basal cell layer and a corrugated epithelial surface.
How do OKCs appear radiologically?
Radiographically, OKCs present as well-defined unilocular or multilocular radiolucencies.
How are OKCs Tx?
Treatment requires complete removal of the lesion, because OKCs are locally aggressive and recurrence rates for inadequately removed lesions can reach 60%.
What is an association with OKCs?
nevoid basal cell carcinoma syndrome (Gorlin syndrome)
What is a Cholesteatoma?
These are associated with chronic otitis media, and are non-neoplastic, cystic lesions 1 to 4 cm in diameter, lined by keratinizing stratified squamous epithelium or metaplastic mucus-secreting epithelium, and filled with amorphous debris commonly affecting the middle and internal ear
What are Branchial Cysts (Cervical Lymphoepithelial Cyst)?
Masses occuring in the upper lateral aspect of the neck along the SCM with the vast majority of these cysts thought to arise from remnants of the second branchial arch and are most commonly observed in young adults between the ages of 20 and 40.
How do bracnhial cysts appear histologically?
fibrous walls usually lined by stratified squamous or pseudostratified columnar epithelium. The cyst wall typically contains lymphoid tissue with prominent germinal centers.
What is this?
Thyroglossal Duct Cyst
How do Thyroglossal Duct Cysts form?
Embryologically, the thyroid anlage begins in the region of the foramen cecum at the base of the tongue; as the gland develops it descends to its definitive midline location in the anterior neck.
Remnants of this developmental tract may persist, which may be lined by stratified squamous epithelium, when located near the base of the tongue, or by pseudostratified columnar epithelium in lower locations.
Thyroglossal Duct Cysts and Histo and Tx?
The connective tissue wall of the cyst may harbor lymphoid aggregates or remnants of recognizable thyroid tissue. The treatment is excision.
Which is more common, esophageal atresia or agenesis?
Absence, or agenesis, of the esophagus is extremely rare, but atresia, in which development is incomplete, is more common.
Atresia occurs most commonly at or near the tracheal bifurcation and is usually associated with a fistula connecting the upper or lower esophageal pouches to a bronchus or the trachea
What causes an imperforate anus?
Imperforate anus , the most common form of congenital intestinal atresia, is due to a failure of the cloacal diaphragm to involute.
What is an esophageal diverticulum?
An esophageal diverticulum is an outpouching of mucosa through the muscular layer of the esophagus. It can be asymptomatic or cause dysphagia and regurgitation.
Diagnosis is made by barium swallow; surgical repair is rarely required.
There are several types of esophageal diverticula, each of different origin. Name some.
Zenker (pharyngeal) diverticula are posterior outpouchings of mucosa and submucosa through the cricopharyngeal muscle, probably resulting from an incoordination between pharyngeal propulsion and cricopharyngeal relaxation.
Midesophageal (traction) diverticula are caused by traction from mediastinal inflammatory lesions or, secondarily, by motility disorders.
Epiphrenic diverticula occur just above the diaphragm and usually accompany a motility disorder (achalasia, diffuse esophageal spasm).
What is this?
Mallory-Weiss tears- Longitudinal mucosal tears/lacerations near the gastroesophageal junction
How do Mallory-Weiss tears most commonly form? Tx?
Most often associated with severe retching or vomiting secondary to acute alcohol intoxication.
These do not generally require surgical intervention, and healing tends to be rapid and complete.
What is Boerhaave syndrome?
Much less common than Mallory-Weiss tears, but a more serious disorder characterized by fully transmural tearing and rupture of the distal esophagus typically in association with vomiting
What is this?
Omphalocele- Occurs when closure of the abdominal musculature is incomplete and the abdominal viscera herniate into a ventral amnioperitoneal membranous sac.
This may be repaired surgically, but as many as 40% of infants with an omphalocele have other birth defects.
What is this?
Gastroschisis- similar to omphalocele except that it involves all of the layers of the abdominal wall, from the peritoneum to the skin.
What is the most frequent site of ectopic gastric mucosa?
the upper third of the esophagus, where it is referred to as an inlet patch
What are the consequences of having an inlet patch?
◦While generally asymptomatic, acid released by gastric mucosa within the esophagus can result in dysphagia, esophagitis, Barrett esophagus, or, rarely, adenocarcinoma.
NOTE: Gastric heterotopia, small patches of ectopic gastric mucosa in the small bowel or colon, may present with occult blood loss due to peptic ulceration of adjacent mucosa.
What is another common form of heteroopic tissue in the GI
Pancreatic tissue can be found in the esophagus or stomach.
Because the rests may be present within any layer of the gastric wall, they can mimic invasive cancer.
What is the most common true diverticulum of the GI tract?
Meckel diverticulum, which occurs in the ileum
This is the most common congenital abnormality of the small intestine; it is caused by an incomplete obliteration of the vitelline duct (ie, omphalomesenteric duct).
Describe formation of a Meckel’s diverticulum
Early in embryonic life, the fetal midgut receives its nutrition from the yolk sac via the vitelline duct. The duct then undergoes progressive narrowing and usually disappears by 7 weeks’ gestation. When the duct fails to fully obliterate, different types of vitelline duct anomalies appear.
Examples of such anomalies include (1) a persistent vitelline duct (appearing as a draining fistula at the umbilicus); (2) a fibrous band that connects the ileum to the inner surface of the umbilicus; (3) a patent vitelline sinus beneath the umbilicus; (4) an obliterated bowel portion; (5) a vitelline duct cyst; and, most commonly (97%) Meckel diverticulum, which is a blind-ending true diverticulum that contains all of the layers normally found in the ileum.
Describe the Rule of 2’s with a Meckel’s Diverticulum
- Occur in approximately 2% of the population
- Are generally present within 2 feet (60 cm) of the ileocecal valve
- Are approximately 2 inches (5 cm) long
- Are 2x more common in males
- Are most often symptomatic by age 2 (only approximately 4% are ever symptomatic).
Describe pyloric stenosis. How does it present?
Congenital hypertrophic pyloric stenosis is three to five times more common in males and occurs once in 300 to 900 live births
Congenital hypertrophic pyloric stenosis generally presents between the third and sixth weeks of life as new-onset regurgitation, projectile, nonbilious vomiting after feeding, and frequent demands for re-feeding.
How does pyloric stenosis present on physical exam?
A palpable, firm, ovoid, 1 to 2 cm abdominal mass. (olive mass)
What are Esophageal mucosal webs?
These are idiopathic ledge-like protrusions of mucosa that may cause obstruction, composed of a fibrovascular connective tissue and overlying epithelium.
What pt. population most commonly has esophageal mucosal webs?
Women, age 40 gastroesophageal reflux, chronic graft-versus-host disease, or blistering skin diseases
What are some associations of esophageal mucosal webs?
In the upper esophagus, webs may be accompanied by iron-deficiency anemia, glossitis, and cheilosis as part of the Paterson-Brown-Kelly (aka Plummer-Vinson syndrome)
What is the main symptom of esophageal webbing?
nonprogressive dysphagia associated with incompletely chewed food.
What is this?
Esophageal rings, or Schatzki rings, are similar to webs, but are circumferential, thicker, and include mucosa, submucosa, and, occasionally, hypertrophic muscularis propria
What is this?
esophageal graft-versus-host disease
Histologic features are similar to those in the skin and include:
- basal epithelial cell apoptosis,
- mucosal atrophy, and
- submucosal fibrosis
- without significant acute inflammatory infiltrates
What is this?
Stress-Related Mucosal Disease- Most critically ill patients admitted to hospital intensive care units have histologic evidence of gastric mucosal damage. Cause likely ischemic.
Stress ulcers are most common in individuals with _____, _____, or ______
shock, sepsis, or severe trauma.
Ulcers occurring in the proximal duodenum and associated with severe burns or trauma are called ___ ulcers.
Curling
What are Cushing ulcers?
Gastric, duodenal, and esophageal ulcers arising in persons with intracranial disease are termed Cushing ulcers and carry a high incidence of perforation.
What is this?
Gastric antral vascular ectasia – a rare cause of gastric bleeding, marked endoscopically by longitudinal stripes of edematous erythematous mucosa that alternate with less severely injured, paler mucosa.
Can also be associated with cirrhosis and systemic sclerosis
What causes the erythematous stripes seen in Gastric antral vascular ectasia?
ectatic mucosal vessels
Describe GAVE histologically?
Histologically, the antral mucosa shows reactive gastropathy with dilated capillaries containing fibrin thrombi.
How does GAVE present?
pts. may present with occult fecal blood or iron deficiency anemia.
How does bowel obstruction present?
The clinical manifestations of intestinal obstruction include abdominal pain and distention, vomiting, and constipation.
What is the most common cause of intestinal obstruction? Younger than 2?
Hernias
Younger than 2- Intussusception is the most common cause of intestinal obstruction in children younger than 2 years of age.
What is this?
Graft-vs-host disease- following hematopoietic stem cell transplantation secondary to donor T cells targeting antigens on the recipient’s GI epithelial cells, however, lamina propria lymphocytic infiltrate is typically sparse.
What is the most common histologic finding of intestinal GVH disease?
Epithelial apoptosis, particularly of crypt cells
What are the most commonly affected regions of the GI tract in GVH disease?
The small bowel and colon are involved in most cases.
What are the zones of the anal canal and their epithelium?
- The upper zone is lined by columnar rectal epithelium;
- the middle third by transitional epithelium; and
- the lower third by stratified squamous epithelium.
What are the most common tumors of the anorectum?
Most commonly SSC (HPV 16 related)- below
Adenocarcinoma about 5% (related to HPV 18)
What are the most significant prognostic factors for patients with anal squamous cell carcinoma (SCC)?
Tumor size (T stage) and nodal status (N stage)
The five-year survival by stage
- T1 – 86 percent
- T2 – 86 percent
- T3 – 60 percent
- T4 – 45 percent
- N0 – 76 percent
- Node-positive – 54 percent
What causes acute appendicitis?
◦thought to be initiated by progressive increases in intraluminal pressure that compromise venous outflow.
◦50% to 80% of cases, acute appendicitis is associated with overt luminal obstruction, usually caused by a small stone-like mass of stool, or fecalith
How is acute appendicitis diagnosed?
requires neutrophilic infiltration of the muscularis propria.
A.
What are the main appendicial tumors?
- carcinoid
- mucinous neoplasms
