ENT Pathology Flashcards
What lines the auditory meatus and external canal, and what glands are present?
Epidermis = contains sebaceous and ceruminous glands
What is the histology of the middle ear?
Columnar lined mucosa, contains ossicles (malleus, incus, stapes), opening of Eustachian tube and mastoid cavity
What structures are present in the inner ear?
Cochlea and vestibular apparatus
What cell type is present in the nasal vestibulae?
Squamous
What cell types are present in the nose and sinus (etc)?
Respiratory epithelium = pseudostratified ciliate columnar
Seromucinous glands
What cell types are present in the throat?
Respiratory and squamous epithelium depending on site
What are the features of the salivary glands?
Exocrine gland = major and minor, acinar component and ductular component
How do the serous cells of the salivary glands stain?
Darkly staining = contain digestive enzymes
How does the mucous component of the salivary glands stain?
Clear grey staining
How do the peripheral myoepithelial cells of the salivary glands appear?
Often flat or cuboidal with clear cytoplasm = may have some contractile properties
What is otitis media?
Inflammation of middle ear = usually viral, sometimes bacterial
What are some organisms that cause otitis media?
Strep. pneumoniae, h. influenzae, moxarella catarrhalis
If chronic = p. aeruginosa, s. aureus, fungal
What is a cholesteatoma?
Not a tumour and doesn’t contain cholesterol = common skin growth, may occur in any age group
Where do cholesteatomas normally arise?
Superior posterior middle ear or petrous apex
What may occur with cholesteatomas?
Chronic otitis media and acquired perforated tympanic membrane
What is the normal lining of the middle ear?
Cuboidal or columnar glandular epithelium
What is the lining of the middle ear when there is a cholesteatoma?
Abnormally situated squamous epithelium = high cell turnover and abundant keratin production, associated inflammation
What are vestibular schwannomas associated with?
Vestibular portion of vestibulocochlear nerve (VIII)
Where do vestibular schwannomas occur?
Within temporal bone = represent 80-90% of cerebellopontine angle tumours
How do vestibular schwannomas present?
95% are sporadic and unilateral, have equal gender distribution
What should be considered as the underlying cause of bilateral vestibular schwannomas in young patients?
Neurofibromatosis type 2
What is the gross appearance of vestibular schwannomas?
Circumscribed tan, white or yellow mass
What causes neurofibromatosis type 2?
May be autosomal dominant but usually sporadic mutation in NF-2 gene = encodes merlin protein at Ch22q12
What lesions occur in neurofibromatosis type 2?
Neurofibromas,, bilateral vestibular schwannomas, multiple meningiomas, gliomas, café au lait, cataracts
What are some causes of rhinitis and sinusitis?
Infection (common cold) or allergy (hay fever) = no requirement to biopsy
What are some features of nasal polyps?
Common (but not in children), equal gender distribution
Consider cystic fibrosis in young patients with polyps
What are some causes of nasal polyps?
Allergy, infection, asthma, aspirin sensitivity, nickel exposure
What is granulomatosis with polyangiitis?
Autoimmune disorder characterised by a small vessel vasculitis and necrosis
Where does granulomatosis with polyangiitis occur?
Usually limited to respiratory tract and kidneys = rare >40 years old
What does granulomatosis with polyangiitis present with?
Pulmonary/renal disease, nasal symptoms of congestion, septal perforation
What antibodies are present in high frequencies in granulomatosis with polyangiitis?
cANCA antibodies
Are tumours of the nose common?
No = relatively rare
What are some benign tumours of the nose?
Squamous papilloma, Schneiderian papilloma, angiofibroma
What are some malignant tumours of the nose?
Most commonly squamous cell carcinoma
Primary adenocarcinoma, nasopharyngeal carcinoma, neuroblastoma, lymphoma
What are the types of Schneiderian papillomas?
Inverted, exophytic or oncocytic
Who gets Schneiderian papillomas?
More common in males, tends to be patients over 50 years old
What are the risk factors for Schneiderian papillomas?
HPV (low risk), smoking, organic solvents, welding
What do Schneiderian papillomas present with?
A blocked nose
Where do Schneiderian papillomas occur?
Inverted/oncocytic = lateral walls and paranasal sinuses Exophytic = nasal septum
Are nasopharyngeal carcinomas common?
No = low incidence in UK (but very high in Far East), more common in males
What are nasopharyngeal carcinomas associated with?
Epstein Barr virus and volatile nitrosamines in food
What kind of carcinomas are nasopharyngeal carcinomas?
Keratinising or non-keratinising squamous cell carcinomas
What are some tumours associated with Epstein Barr virus?
Burkitt’s lymphoma, other B-cell lymphomas, Hodgkin’s lymphoma
What does Epstein Barr virus infect?
Epithelial cells of oropharynx and B-cells
What is Epstein Barr infection often described as being?
Ubiquitous = often subclinical, occasional infectious mononucleosis
How does Epstein Barr virus interfere with the immune system?
Hijacks and mimics T helper cell responses leading to proliferation and survival of B cells
What mediates the action of Epstein Barr virus?
Latent membrane protein 1 (LMP-1) = encodes EBNA-2 activating cyclin D and promotes transition from G0 to G1
Are laryngeal polyps common?
No = rare reactive change to laryngeal mucosa
What may cause a laryngeal polyp?
Vocal abuse, infection, smoking and occasionally hypothyroidism
How do laryngeal polys appear?
Unilateral and pedunculated
Where do laryngeal nodules present?
Usually young women = bilateral on middle 1/3 to posterior 1/3 of vocal cord
What is a contact ulcer of the throat?
Benign response to injury = usually posterior vocal cord
What are some risk factors for developing a contact ulcer in the throat?
Chronic throat clearing, voice abuse, GORD, intubation
What age groups are squamous papillomas of the throat common in?
In children <5 years old and adults aged between 20-40
What is squamous papilloma of the throat associated with?
HPV exposure = types 6 and 11
How does squamous papilloma of the throat present?
Aggressive in children
In adults often solitary and not related to HPV
What are paragangliomas?
Tumours arising in clusters of neuroendocrine cells dispersed throughout the body
Where do chromaffin positive paragangliomas occur?
Sympathetic nervous system, usually adrenal medulla or paravertebral = can secrete catecholamines
Where do non-chromaffin positive paragangliomas occur?
Carotid/aortic bodies, jugulotympanic ganglia, ganglia nodosum of vagus, clusters around oral cavity, nose, nasopharynx, larynx, orbit
Are paragangliomas common?
No = rare, usually occur in patients over 50
What condition can paragangliomas occur as part of?
MEN2 = autosomal dominant inheritance, usually multiple, higher incidence of malignant forms
Where do squamous cell carcinomas of the head and neck occur?
Nose, sinuses, pharynx, larynx, oral cavity
What are risk factors of squamous cell carcinomas of the head and neck?
Smoking and alcohol
What site of squamous cell carcinoma of the neck is most associated with HPV?
The oropharynx
What type of HPV is associated with squamous cell carcinomas of the oropharynx?
Majority HPV type 16
What proteins does HPV type 16 produce which helps develop squamous cell carcinoma of the oropharynx?
Proteins E6 and E7 = disrupt p53 and RB pathways respectively, leading to cellular immortality
Do squamous cell carcinomas associated with HPV type 16 have a good prognosis?
Yes = have greatly improved prognosis and sensitivity to treatment
What is the staging of laryngeal squamous cell carcinomas?
T1a = one vocal cord T1b = both vocal cords T2 = extension into supra/subglottis T3 = vocal cord fixation/extension into paraglottic space, minor thyroid cartilage involvement T4a = thyroid cartilage, trachea, muscles of tongue, strap muscles, thyroid, oesophagus T4b = prevertebral space, mediastinal structures, carotid artery
What are some examples of salivary glands?
Parotid, submandibular, sublingual, minor salivary glands
What is sialolithiasis?
Stones in the salivary glands
What occurs in paramyxovirus (mumps) infection of the salivary glands?
Bilateral parotitis, associated orchitis and pancreatitis, risk of secondary meningitis
What are some tumours of the salivary glands?
Pleomorphic adenoma, Warthin’s tumour, mucoepidermoid carcinoma, adenoid cystic carcinoma
Where is the most common site for tumours of the salivary glands?
Parotid gland
What are some signs that would make you consider a malignancy of the salivary glands?
Tumours in smaller glands, if patient is young, if tumour is painful
What is the most common tumour of the salivary glands?
Pleomorphic adenoma = usually females aged 40-60 in parotid with a long history (can occur in any gland at any age)
Why do pleomorphic adenomas of the salivary glands have a high rate of recurrence?
They are difficult to excise
What is the risk associated with longstanding pleomorphic adenomas?
Risk of malignant transformation
What is Warthin’s tumour of the salivary glands?
Second most common benign tumour = usually males >50, rare outwith parotid, often bilateral and multicentric
What are Warthin’s tumours of the salivary glands associated with?
Strong link with smoking
What is the most common malignant tumour of the salivary gland worldwide?
Mucoepidermoid carcinoma = wide age range, no gender predominance
Where is the most common site for mucoepidermoid carcinomas of the salivary gland?
Parotid glands (can occur in any gland)
How are mucoepidermoid tumours of the salivary glands classified?
High or low risk = low grade has 5 year survival of >90%, high grade has 5 year survival of <60%
What is the most common malignant tumour of the salivary gland in the UK?
Adenoid cystic carcinoma
What are some features of adenoid cystic carcinomas of the salivary glands?
Usually patients over 40 years old, most common malignant tumour of palate, 5 year survival of 35%
Where do adenoid cystic carcinomas of the salivary gland frequently invade?
Frequent perineural invasion = associated pain or loss of function
