Pathology Flashcards
Rhinitis
Inflammation of the nasal mucosa
Allergic rhinitis
- subtype of rhinitis due to type I hypersensitivity (immediate hypersensitivity)
- characterized by inflammatory infiltrate with eosinophils
- associated with other atopic disorders (asthma and eczema)
What cells type I hypersensitivity reactions associated with?
early phase: sensitized mast cells and basophils
late phase: eosinophils
Mechanism of type 1 hypersensitivity
Sensitization:
- antigen is presented to CD4+ Th2 cells specific to the antigen
- TH2 cells stimulate B-cell produce of IgE antibodies to that antigen
- IgE binds to Fcε receptors on the surface of tissue mast cells and blood basophils
Hypersensitivity
- later exposure to antigen crosslinks the bound IgE on sensitized cells –> degranulation
- release of initial mediators pre-formed mediators
- histamine (bronchoconstriction, mucus secretion, vasodilation, vascular permeability)
- tryptase (proteolysis)
- kininogenase (kinins and vasodilation, vascular permeability, edema)
- ECF-A (attact eosinophil and neutrophils)
- Formation and release of late stage mediators
- leukotriene B4 (basophil attractant)
- leukotriene C4, D4 (same as histamine but 1000x more potent)
- prostaglandins D2 (edema and pain)
- PAF (platelet aggregation and heparin release –> microthrombi)
What are patients who have repeated bouts of rhinitis at risk for?
Development of nasal polyps
Nasal polyp
Protrusion of edematous, inflamed nasal mucosa usually secondary to repeated bouts of rhinitis
- Child with nasal polyps –> think cystic fibrosis
- Also occurs in patients with aspirin-intolerant asthma
Aspirin intolerant asthma
Characterized by a triad of
- asthma
- aspirin-induced bronchospasms
- nasal polyps (~10% of asthmatic adults)
2 conditions associated w/ nasal polyps
- aspirin intolerant asthma
- cystic fibrosis (children typically)
Angiofibroma
- Benign tumor of nasal mucosa composed of large blood vessels and fibrous tissue
- classically seen in adolescent males (very very rarely seen in female)
- presents with profuse epistaxis (nose bleed)
Nasopharyngeal carcinoma
- Malignant tumor of nasopharyngeal epithelium
- associated with EBV
- Classically seen in African children and Chinese adults
- Often presents with involvement of cervical lymph nodes
- Biopsy usually reveals pleomorphic keratin-positive epithelial cells (poorly differentiated squamous cell carcinoma) in the background of lymphocytes
Intermediate filament that can be stained for in epithelial cells? What type of cancers is it associated with?
Keratin – carcinomas
Acute epiglottitis
Inflammation of the epiglottis
H influenza type B is most common cause (immunized or nonimmunized)
Acute epiglottitis presentation
- High fever, sore throat (due to inflammation in that region)
- drooling with dysphagia (swollen epiglottis –> compromised airway –> dysphagia (difficulty swalling))
- muffled voice, inspiratory stridor (compromised airway)
Risk of acute airway obstruction
Laryngotracheobronchitis
Inflammation of the upper airway
Parainfluenza virus is the most common cause
Presents with a hoarse, “barking” cough and inspiratory stridor
Patient presents with a hoarse, “barking” cough and inspiratory stridor
laryngotracheobronchitis
laryngotracheobronchitis most common cause
parainfluenza virus (RNA virus)
vocal cord nodule
Nodule that arises on vocal cord.
Most often due to excessive use –> bilateral presentation
Nodule is composed of degenerative (myxoid) connective tissue
Presents with hoarseness; resolves with rest
vocal cord nodule - most common cause
wear and tear – excessive use
resolves with rest
Laryngeal papilloma
- Benign papillary tumor of vocal cord
- Due to HPV 6 and 11 (b/c its HPV, you would expect koilocytic change on biopsy)
- Single mass in adults and multiple in children
- Presents with hoarseness
Laryngeal papilloma causes
HPV 6 and 11 –> will cause koilocytic change
Laryngeal carcinoma
Squamous cell carcinoma arising from epithelial lining of vocal cord
Risk factors: alcohol and tobacco
Possible to get larygneal carcinoma that evolves from laryngeal papilloma (as it is due to a HPV virus)
Presents with hoarseness; other signs include cough and stridor
Laryngeal carcinoma risk factors
Biggest ones: alcohol and tobacco
Rare, but can occur: laryngeal papilloma —> laryngeal carcinoma
Pneumonia
Infection of the lung parenchyma
occurs when normal defenses are impaired
- cough reflex (not able to remove organisms/particles that we normally would cough up
- dmg to mucociliary escalator
- mucous plugging
What normal defenses are typically damaged to allow for pneumonia?
- cough reflex (not able to remove organisms/particles that we normally would cough up
- dmg to mucociliary escalator
- mucous plugging
Pneumonia clinical features
- fever and chills (due to organism leaking out into the blood)
- cough with yellow-green and rusty sputum (yellow green = pus, rusty = blood)
- tachypnea with pleuritic chest pain (pain when you breathe in due to stretching of the pleura)
- decreased breath sounds with dullness to percussion (dullness due to the exudates from inflammation)
- elevated WBC count
Diagnosing pneumonia clinically
chest x-ray
sputum gram stain and culture
blood cultures
pneumonia patterns on chest x-ray
- Lobar pneumonia – consolidation to an entire lobe
- bronchopneumonia – consolidation that runs along the small airways
- interstitial pneumonia – no consolidation but infection of the intersitium of the lung (the connective tissue of the alveolar air sacs). xray will show diffuse lung markings
1 & 2 are typically associated with bacterial infections
3 is considered atypical pneumonia and is more often associated with viral infections
What types of pneumonia patterns on chest x-ray are associated with bacterial infections?
Lobar pneumonia
bronchopneumonia
What types of pneumonia patterns on chest x-ray are associated with viral infections?
interstitial pneumonia
Lobar pneumonia
Consolidation of infection to an entire lobe
Usually bacterial
Most common causes:
- S pneumoniae (95%)
- Klebsiella pneumoniae
Most common cause of community-acquired pneumonia
Streptococcus pneumoniae – ~95% of all pneumonia
Usually in middle-aged adults and elderly
Klebsiella pneumoniae
Causes ~5% of pneumonia via aspiration of enteric flora.
Affects mostly (people most at risk for aspiration):
- elderly in nursing homes
- alcoholics
- diabetics
This bug has a thick mucoid capsule. When coughed up, it will give the sputum a gelatinous (currant jelly) sputum.
Often complicated by an abscess.
4 classic phases of lobar pneumonia
- Congestion (infection –> dilation of vessels and increased permeability –> edema = congestion)
- Red hepatization (exudate, neutrophils, and hemorrhage filling the alveolar air sacs)
- grey hepatization (breakdown of the RBCs within the exudate from the red hepatization step)
- resolution (via regeneration by the type II pneumocyte)
hepatization refers to the lung becoming solid instead of spongy (like the liver) due to the exudate and blood.
What occurs in the recovery process after a pneumonia infection? What cell type is predominantly responsible for this?
Patient regenerates the part of the lung that was infected.
This is done by the type II pneumocyte (stem cell of the lung)
Secondary pneumonia
- Bacterial pneumonia superimposed on a viral upper respiratory tract infection
- Idea is that the initial viral infection knocks out the mucociliary escalator and increases the risk of developing pneumonia
Most common cause of secondary pneumonia
Staphylococcus aureus
Complications of S. aureus infection
abscess or empyema (pus in the pleural space)
Haemophilus influenzae
Commonly causes secondary pneumonia or pneumonia superimposed on COPD (leads to exacerbation of COPD)
Pseudomonas aeruginosa
commonly associated with pneumonia in cystic fibrosis patients
Moraxella catarrhalis
Commonly associated with community-acquired pneumonia and penumonia superimposed on COPD (leads to exacerbation of COPD)
Legionella pnemophilia
Commonly associated with:
- community-acquired pneumonia
- pneumonia superimposed on COPD
- pneumonia in immunocompromised states
transmitted from water source
intracellular organism best visualized by silver stain
Most common causes of bronchopneumonia
- S. aureus
- H. influenzae
- P. aeruginosa
- M. catarrhalis
- L. pneumophila
Interstitial pneumonia
Aka atypical pneumonia – diffuse interstitial infiltrates of the lung
Symptoms are more atypical – presents with relativley mild upper respiratory symptoms
- minimal sputum
- cough
- low fever
Interstitial pneumonia symptoms
“atypical”
Presents with relativley mild upper respiratory symptoms
- minimal sputum
- cough
- low fever
Bugs associated with interstitial pneumonia
“atypical”
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Respiratory syncytial virus (RSV)
- Cytomegalovirus (CMV)
- Influenza virus
- Coxiella burnetii
Mycoplasma pneumoniae
Most common cause of atypical pneumonia
Usually affect young adults (military recruits or college students living in a dormitory)
Complications:
- autoimmune hemolytic anemia (IgM against I antigen on RBCs causes cold hemolytic anemia)
- erthema multiforme
Chlamydia pneumoniae
Second most common cause of atypical pneumonia in young adults
Respiratory syncytial virus (RSV)
Most common cause of atypical pneumonia in infants
Cytomegalovirus (CMV)
Commonly associated with atypical pneumonia with posttransplant immunosuppressive therapy
Influenza virus
Commonly associated with atypical pneumonia in:
- elderly
- immunocompromised
- those with preexisting lung disease
Increases risk for superimposed S aureus or H influenzae bacterial pneumonia
- most deaths are not associated with virus infection but rather the secondary bacterial pneumonia that follows due to the weakening of the defense mechanisms
Coxiella burnetii
- Associated with atypical pneumonia with high fever (Q fever)
- normal atypical pneumonia causes low fever
- Seen in farmers and veterinarians (Coxiella spores are deposited on cattle by ticks or are present in cattle placentas)
-
Coxiella is a rickettsial organism, but it is distinct from most rickettsiae because:
- it causes pneumonia
- does not require arthropod vector for transmission (survives as highly heat-resistant endospores)
- does not produce a skin rash
Why is Coxiella burnetii distinct from most rickettsiae?
- it causes pneumonia
- does not require arthropod vector for transmission (survives as highly heat-resistant endospores)
- does not produce a skin rash
Aspiration pneumonia
Seen in patients at risk for aspiration (ie alcoholics and comatose patients)
Due to anaerobic bacteria in oropharynx
- Bacteroides
- Fusobacterium
- Peptococcus
Classically results in right lower lobe abscess
Most common anaerobic bacteria in oropharynx
- Bacteroides
- Fusobacterium
- Peptococcus
Aspiration pneumonia - where does it classically present and why?
Right lower lobe abscess because the right main stem bronchus branches at a less acute angle than the left –> more easier for the bacteria to go down the right than the left –> right lower lob abscess
Tuberculosis - bug responsible
Mycobacterium tuberculosis
Typically from inhalation –> results in primary TB
Primary TB
Arises with initial exposure
Results in focal caseating necrosis in the lower lobe of lung and hilar lymph nodes
Foci undergo fibrosis and calcification forming Ghon complex.
Primary TB is generally asymptomatic but leads to a positive PPD
Ghon complex
a lesion seen in the lung that is caused by tuberculosis. The lesions consist of a calcified focus of infection and an associated lymph node.
i.e. a foci that has undergone fibrosis and calcification
Primary TB - clinical features
Usually asymptomatic.
X-ray/biopsy (after death) will show the formation of Ghon complexes (areas of calcification and fibrosis due to bacterial presence)
PPD +
Secondary TB
Arises with the reactivation of TB
Commonly due to AIDS, may also be seen with aging
Occurs at apex of lung – b/c oxygen tension is the highest at the apex of the lung
Forms cavitary foci of caseous necrosis –> may lead to miliary pulmonary TB or tuberculous bronchopneumonia
What causes secondary TB?
Reactivation of the ghon complex (ie primary TB)
Where does secondary TB most often occur? and why?
Apex of the lung because that is where the oxygen tension is the highest
Secondary TB - clinical features
- Fevers and night sweats
- cough with hemoptysis
- weight loss
- biopsy reveals caseating granulomas
- AFB stain reveals acid-fast bacilli
TB - where can it spread?
Can involve any tissue, but most high yield places:
- Meninges (meningitis) – w/ granulomas at the base of the brain
- Cervical lymph nodes
- Kidney (sterile pyuria) – most common
- Lumbar vertebrae (Pott disease)
Cleft lip and palate
- Full-thickness defect of lip or palate
- Due to failure of facial prominences to fuse
- Cleft lip and palate usually occur together
Aphthous Ulcer
- Painful, superifical ulceration of oral mucosa
- arises in relation ot stress and resolves spontaneously, but often recurs
- characterized by grayish base surrounded by erythema
Behcet Syndrome
Presents as a triad
- recurrent aphthous ulcers
- genital ulcers
- uveitis
Due to immune complex vasculitis involving small vessles.
Can be seen after viral infection, but etiology is unknown
Triad associated with Behcet Syndrome
- recurrent aphthous ulcers
- genital ulcers
- uveitis
Oral Herpes
Vesicles involving oral mucosa that rupture resulting in shallow, painful, red ulcers
Usually due to HSV-1
- Primary infection occurs in childhood. Lesions heal, but virus remains dormant in ganglia of trigeminal nerve.
- Stress and sunlight cause reactivation of virus
- Leads to vesciles that often arise on lips (cold sore)
Most common cause of oral herpes
HSV-1
Where does herpes simple viruses lay dormant in oral herpes?
ganglia of trigeminal nerve
Oral herpes
Squamous cell carcinoma of the oral mucosa
Malignant neoplasm of squamous cells lining oral mucosa
Major risk factors
- tobacco
- alcohol
Floor of mouth is most common location
Major risk factors for squamous cell carcinoma of the oral mucosa
tobacco
alcohol
Most common location for squamous cell carcinoma of the oral mucosa
floor of the mouth
Squamous dysplasia of the oral mucosa
Often presents as luekoplakia (white plaques) and erythroplakia (red plaque)
often biopsied to rule out carcinoma
Patient presents with oral leukoplakia, what 3 things come to mind?
Have to distinguish between 3 things:
- squamous cell dysplasia – presents as a white plaque that cannot be scraped away
- oral candidiasis (thrush) – white deposit on the tongue that is easily scraped away. Usually seen in immunocompromised states
- Hairy luekoplakia – white, rough (‘hairy’) patch that arises on the lateral tongue. Usually seen in immunocompromised individuals (AIDS) and is due to EBV-induced squamous cell hyperplasia. NOT premalignant
Erythoplakia of oral mucosa
‘Red plaque’
Represents vascularized luekoplakia, ie a lot of new growth that includes angiogenesis
Highly suggestive of squamous cell dysplasia
What is suggestive of squamous dysplasia of oral mucosa?
Erythoplakia and leukoplakia.
Erythoplakia is more much indicative that there is dysplasia. Leukoplakia needs to rule out candidiasis and hairy luekoplakia
Major Salivary Glands (3)
- Parotid
- Submandibular
- Sublingual
Mumps
Infection with mumps virus
results in bilateral inflamed parotid glands
Can also cause
- orchitis (infection of testicles) –> risk of sterility (teenagers)
- pancreatitis – will result in increased serum amylase (but need to becareful, because both the gland and the pancreas produce amylase)
- aseptic meningitis
Mumps - complications (3)
- orchitis (infection of testicles) –> risk of sterility (teenagers)
- pancreatitis – will result in increased serum amylase (but need to becareful, because both the gland and the pancreas produce amylase)
- aseptic meningitis
Mumps - why is there an increase in serum amylase?
Both overactivity of the infected glands (bilateral parotid) and possible pancreatitis.
Sialadenitis
Inflammation of the salivary gland
Most commonly due to an obstruction stone (sialolithiasis) leading to S aureus infection.
- whenever you block a tube, you increase the likelihood of an infection behind the tube
usually unilateral
sialolithiasis
Also termed salivary calculi or salivary stone
A condition where a calcified mass or sialolith forms within a salivary gland, usually in the duct of the submandibular gland
What is the biggest issue associated w/ sialadenitis?
sialolithiasis leading to an S. aureus infection
Pleomorphic adenoma
- Most common tumor of salivary gland
- Benign tumor composed of stromal (ie cartilage) AND epithelial tissue (ie glands)
- whenever a tumor comprises of 2 tissues, it is called a biphasic tumor
- Usually arises in parotid
- Presents as a mobile, painless, circumscribed mass at angle of jaw
- all the key characteristics of being benign
- mobile = did not invade tissue
- painless = has not invaded the facial nerve (runs right through parotid gland)
- circumscribed = different from all the tissue surrounding it (hence foreign, but benign)
- all the key characteristics of being benign
- High rate of recurrence
- mostly due to the fact that this tumor has irregular margins and inexperienced surgeons are more likely to leave a little bit of tissue behind that allows to regrowth
- Rarely may transform into carcinoma
- presents with signs of facial nerve damage
Pleomorphic adenoma - most common location and presentation
Arises in parotid.
Presents as a mobile, painless, circumscribed mass at angle of jaw
- all the key characteristics of being benign
- mobile = did not invade tissue
- painless = has not invaded the facial nerve (runs right through parotid gland)
- circumscribed = different from all the tissue surrounding it (hence foreign, but benign)
Why is there a high rate of recurrent of pleomorphic adenomas?
mostly due to the fact that this tumor has irregular margins and inexperienced surgeons are more likely to leave a little bit of tissue behind that allows to regrowth
Pleomorphic adenoma - what happens when this tumor transforms into a carcinoma? How do you tell?
Patients will likely present with pain (invasion/destruction of the facial nerve in the parotid gland)
Warthin tumor
Benign cystic tumor with abundant lymphocytes and germinal centers
- cystic tumor with lymph node tissue
2nd most common tumor of salivary gland
almost always arises in parotid – common for LN tissue to be associated with parotid
Warthin tumor - where does it most commonly arise?
Parotid gland – this gland is one of the last glands to embryologically separate out and is not uncommon for it to be associated with lymphoid tissue
Mucoepidermoid carcinoma
Malignant tumor composed of mucinous and squamous cells
Usually arises in parotid; commonly involves the facial nerve (dmg to this nerve is common in malignancies)
TE fistula
Congenital defect resulting in connection between the esophagus and trachea
multiple different variants, most common: atresia of the proximal esophagus w/ connection of the distal esophagus (other end) to the trachea.
Presents with:
- vomiting – food goes into esophagus, but b/c it is closed, it will come right back up
- excess amniotic fluid (polyhydramnios) – during gestation, baby will “eat” some of the amniotic fluid. Since the esophagus is blocked, baby can’t so will be left with excess amniotic fluid in the sac
- abdominal distension – air into the stomach (via fistula)
- aspiration – stomach contents coming back up
Esophageal web
Thin protrusion of esophageal mucosa, most often in upper mucosa
Presents with dysphagia for poorly chewed food
Increased risk for esophageal squamous cell carcinoma
Plummer-Vinson Syndrome
Severe iron deficiency anemia
esophageal web
beefy-red tongue due to atrophic glossitis
- due to atrophy of the mucosa. Redness due to exposure of the underlying vasculature
Zenker diverticulum
Outpouching of pharyngeal mucosa through acquired defect in the muscular wall
- typically due to some abnormal pressure in the pharynx when you are swallowing
Arises above upper esophageal sphincter at junction of esophagus and pharynx
Presents with dysphagia, obstruction and halitosis (bad breathe – food trapped can rot)
Also known referred to sometimes as a “false” diverticulum
- means you only protruded one part of the wall and it does not include the muscularis layer
False diverticulum
A diverticulum that does not include the muscularis or adventitia. Typically very superifical diverticulum.
Most of the GI diverticulums (including Zenker’s) are false diverticulums
Mallory-Weiss Syndrome
Longitudinal laceration of mucosa at GE junction
Caused by severe vomiting –> which causes a longitudinal laceration of the GE mucosa as the vomit comes up each time.
- Usually due to alcoholism or bulimia
Presents with painful hematemesis (laceration bleeds into the vomit)
Risk of Boerhaave syndrome
Boerhaave syndrome
Rupture of esophagus, typically occuring after forceful emesis. Associated with but also different than Mallory-Weiss syndrome (which is a nontransmural esophageal tear)
Rupture of esophagus –> air in the mediastinum –> air track up through the facial planes and get into the subcutaneous tissue (esp in region of neck) –> subcutaneous emphysema (air beneath the skin); will get crackling when you press the skin
Esophageal varices
Dilated submucosal veins in lower esophagus
Arise secondary to portal HTN (a portion of the blood supply to the esophagus drains into the portal system (the majority going via azygous vein into the SVC))
Asymptomatic, but risk fo rupture exists (painless hematemesis if ruptured)
most common type of death in patients with cirrhosis (who all have portal hypertension, and reduce coagulation factors –> massive bleeding)
What is the most common cause of death in patients with cirrhosis? and why?
Esophageal varices.
Patients with cirrhosis have malfunctional liver alongside portal hypertension. The portal hypertension predisposes them to esophageal varices that can rupture and the malfunctional liver reduces the production of coagulation factors so any kind of bleed will be amplified with an inability to clot.
Achalasia
A = without, chalasia = relaxation
Disordered esophageal motility with inability to relax LES
Due to damaged ganglion cells in myenteric plexus
- dmg can be idiopathic or secondary to known insult (ie Chagas disease – trypanosome infection)
2 factors associated with achalasia
- inability to relax the LES
- dysfunctional esophageal motility
Achalasia - clinical features
3, 4 – Inability to relax the LES –> buildup of food at the LES = increased LES pressure –> expansion of the esophageal walls to accomodate the buildup == bird beak sign
- Dysphagia for solids and liquids – both solids and liquids require the peristalsis of the esophageal wall
- Putrid breathe - solids accumulates in the esophagus and will rot creating the bad breathe
- High LES pressure on esophageal manometry
- “bird-beak” sign on barium swallow
- Increased risk for esophageal squamous cell carcinoma
GERD
Gastroesophageal reflux disease
reflux of acid from the stomach due to reduced LES tone
Risk factors:
- alcohol
- tabacco
- obesity
- fat-rich diet
- caffeine
- hiatal hernia (hernia of the stomach into the esophagus which bypasses the LES. W/o the LES, the changes of reflux are significantly higher)
Clinical features
- heartburn (mimics cardiac chest pain)
- asthma (adult-onset) and cough
- damage to enamel of teeth
- ulceration with stricture and Barrett esophagus are late complications
Normal cellular lining of the esophagus
Non-keratinizing squamous epithelium
What does the lining of the esophagus change into due to GERD?
Non-ciliated columnar cells with goblet cells