Path Chapter 16: Head and Neck
Oral cavity:
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Teeth are surrounded by gingival mucosa – page 740
The crown of the tooth projects into the mouth, and is covered by enamel, which is hard
acellular tissue, and the most highly mineralized tissue in the body
Enamel sits on dentin, which is a specialized form of connective tissue that makes up most of
the remaining hard part of the tooth
o Dentin is cellular and has many dentinal tubules, which have cytoplasmic extensions of
odontoblasts
o Odontoblasts line the meeting of the dentin and pulp, and can make new (secondary)
dentin when stimulated
The pulp chamber is surrounded by the dentin and has stroma rich in nerve bundles,
lymphatics, and capillaries
Teeth are attached to the jaws by the periodontal ligament, which provides a strong but flexible
attachment that can withstand the forces of chewing
o The periodontal ligament attaches to the jaw bone on one side, and the cementum at
the roots of the teeth on the other side
 Cementum acts like cement to attach the teeth to the periodontal ligament
Dental caries (tooth decay) – localized degradation of the tooth
o The most common cause of tooth loss before age 35
o Caries happen from the tooth mineral getting dissolved by acidic metabolic products
from bacteria in the oral cavity, from metabolizing sugars
o Fluoride prevents caries by incorporating into the crystalline structure of the enamel,
forming fluorapatite, and adds to the resistance to degradation by bacterial acids
Gingiva – squamous mucosa in between the teeth and around them
Gingivitis – inflammation of the gingival mucosa and associated soft tissues
o Gingivitis develops from lack of proper oral hygiene, causing accumulation of dental
plaque and calculus
o Dental plaque – sticky, colorless biofilm that builds on teeth, formed by oral bacteria,
proteins from saliva, and desquamated epithelial cells
o If plaque continues to build and isn’t removed, it becomes mineralized to form calculus
(tartar)
o The bacteria in the plaque release acids from sugar-rich foods, which erode the enamel
surface of the tooth, and when this happens chronically it leads to caries (tooth decay)
o Plaque build-up beneath the gumline can cause gingivitis
o Chronic gingivitis is characterized by gingival erythema, edema, bleeding, and loss of
soft-tissue adaptation to teeth
o Gingivitis happens at any age, but is most common and severe in adolescence
o Gingivitis is reversible, and you fix it by decreasing accumulation of plaque and calculus
through brushing and flossing
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Periodontitis – inflammation of the supporting structures of the teeth, including the periodontal
ligaments, alveolar bone, and cementum
o If untreated, periodontitis can progress and cause loss of attachment from destruction
of the periodontal ligament and alveolar bone
 This can loosen and cause loss of teeth
o Periodontitis is caused by bad bacteria causing too many bad effects at these sites
 Healthy bacteria are usually gram positives, while the periodontitis-causing
bacteria are usually gram negative
 The main causes of periodontitis are aggregatibacter (actinobacillus)
actinomycetemcomitans, porhyromonas gingivalis, and prevotella intermedia
o Periodontitis usually presents by itself, but it can also be part of AIDS, leukemia,
Chrohn’s, diabetes, Down syndrome, sarcoidosis, and neutrophil problems
o Organisms from periodontitis can also turn systemic and cause endocarditis &
abscesses
Reactive soft tissue nodules of the oral cavity are common
o The most common fibrous proliferative lesions of the oral cavity are fibromas and
granulomas
o Irritation fibromas happen mainly in the buccal mucosa at the bite line or where the
gingiva meets the teeth – page 741 top pic
 An irritation fibroma is a raised nodule of fibrous tissue in the mouth, that you
treat by excising it
o A pyogenic granuloma is a very vascular lesion usually in the gingiva of kids, teens, and
pregnant women (aka pregnancy tumor) – page 741 bottom pic
 The surface is ulcerated and looks bright red/purple
 Growth can be very rapid, with lots of vascular proliferation
 They can regress after pregnancy, turn fibrous, or turn into a peripheral
ossifying fibroma
 You treat a pyogenic granuloma by excising it
o A peripheral ossifying fibroma is a common reactive growth of the gingiva, that looks
like a red, ulcerated nodule
 They tend to recur, so you have to excise down ot the periosteum to remove it
o Peripheral giant cell granuloma is a common lesion of the gingiva, covered by intact
gingival mucosa usually, that looks more blue/purple, and is made of giant cells
Apthous ulcers (canker sores) – extremely common superficial ulcers of the oral mucosa that
affect almost half of people
o They’re more common in people 20 or younger, very painful, and often recurrent
o Canker sores tend to be more prevalent in certain families
o Canker sores are shallow, hyperemic ulcers covered with a thin exudate and rimmed by
a zone of erythema – page 742
o They can spontaneously resolve within 10 days, or last weeks
Glossitis – inflammation of the tongue, usually referring to the “beefy-red” tongue seen in
certain deficiencies
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Glossitis happens from atrophy of the papillae of the tongue and thinning of the
mucosa, exposing the underlying vasculature
o The atrophic changes can sometimes lead to inflammation and shallow ulcers
o Glossitis can happen in B vitamin deficiencies, & also in sprue & iron-deficiency anemia
o Plummer-Vinson-Paterson-Kelly syndrome – combo of iron deficiency anemia, glossitis,
and dysphagia, with webs
o Glossitis with ulcers can also happen from teeth, bad dentures, syphilis, or inhaling or
ingesting chemicals
Infections of the oral cavity:
o Oral mucosa is very resistant to its normal flora
o Oral defenses include competitive suppression by native organisms, secretory IgA,
antibacterials in saliva, and irrigating effects of food or drink
o Immunodeficiency and antibiotics are 2 things that can mess up this oral defense
o Herpes simplex virus (HSV) – most orofacial HSV is HSV-1
 Oral sexual habits though can let HSV-2 get on the face
 Primary HSV infection usually happens in kids 2-4 years old, is often
asymptomatic, and doesn’t cause much problem
 Up to 1/5 of the time, primary HSV infection presents as acute herpetic
gingivostomatitis, with abrupt onset of blisters and ulcers throughout the oral
cavity, especially in the gingiva, along with swollen lymph nodes and fever
 The blisters start filled with a clear serous fluid, that often rupture to form a
very painful red-rimmed shallow ulcer
 You may see intranuclear viral inclusions, or cells may fuse into giant cells
 You can diagnose with a Tzanck test that looks at the blister fluid under a
microscope
 The blisters go away within 3-4 weeks, but the virus gets into regional nerves
and eventually becomes dormant in the local trigeminal ganglia
 Most adults have HSV-1, but only a minority have the virus reactivate to form a
cold sore, usually in young adults
 Things that can reactivate include trauma, allergies, exposure to UV light, upper
respiratory infection, pregnancy, menstruation, immunosuppression, and
exposure to extreme temperatures
 Recurrent herpetic stomatitis happens either at the primary site of inoculation,
or in nearby mucosa of the same ganglion
 It looks like groups of small blisters, that dry up in 4-6 days and heal
within 10
 The most common sites for recurrent HSV is the lips (herpes labialis)
nasal orifices, buccal mucosa, gingiva, and hard palate
o Oral candidiasis (thrush) – most common fungal infection of the oral cavity
 Candida albicans is part of the normal oral flora in half of people
 Pseudo-membranous (thrush) is the most common form of oral candidiasis
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Oral candidiasis looks like curd-like gray/white inflammation made of organism
and exudate, that can be scraped off
 Thrush only causes problems in immunosuppressed people, like in diabetes,
antibiotic use, AIDS, etc.
o Page 744 – table of when oral lesions are signs of systemic disease
o Hairy leukoplakia – oral lesion that is white, merging patches of fluffy (“hairy”)
hyperkeratotic thickenings, almost always found on the lateral border of the tongue
 4/5 of people with hairy leukoplakia have HIV
 The other 1/5 happen from other causes of immunosuppression, like cancer
therapy or transplant immunosuppression
 Unlike thrush, hair leukoplakia can’t be scraped off
 Under microscope, hairy leukoplakia characteristically shows
hyperparakeratosis & acanthosis w/ “balloon cells” in the upper spinous layer
 Sometimes there is koilocytosis of the superficial, nucleated epidermal cells,
suggesting HPV, but it can also be EBV
 In hairy leukoplakia from HIV, AIDS symptoms show up within 2-3 years
Oral cancers are common worldwide, and have a fairly high mortality
Leukoplakia – white patch or plaque that can’t be scraped off and can’t be characterized as any
other disease, so basically if a white lesion can be diagnosed anything else, it’s not leukoplakia,
otherwise it is, so they’re there for no apparent reason – page 746
o So white patches from candida or lichen planus are not leukoplakia
o About 3% of people have leukoplakia, and only at most ¼ is precancerous
 But until proven otherwise, leukoplakia is considered precancerous
o Leukoplakia can be hyperkeratotic over a thick acanthotic mucosal epithelium, or be
dysplastic
Erythroplakia – red, velvety, possible eroded area in the oral cavity that isn’t raised and may
even depress – page 745
o The epithelium is atypical and dysplastic, making it much higher risk for malignant
transformation than leukoplakia
Both leukoplakia and erythroplakia can happen at any age, but are most common at ages 40-70,
and more often in males
The most common cause of leukoplakia & erythroplakia is tobacco, both smoke & chew
Most (95%) of cancers of the head and neck are squamous cell carcinomas (HNSCC), usually
coming from the oral cavity
o HNSCC is an aggressive epithelial malignancy that is one of the most common cancers in
the world
o Long term survival from a HNSCC is less than 50%
 Early stages have good survival rates, but late stage is pretty bad
 This is due to the cancer being diagnosed usually when it’s already reached late
stage
o HNSCC’s also have the highest rate of developing more than one primary tumor of any
cancer, which also decreases chances of survival
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Field cancerization – theory saying multiple individual primary tumors develop
independently in the upper aerodigestive tract from years of chronic exposure of the
mucosa to carcinogens
o People with an HNSCC that survives 5 years has a 1/3 chance of developing a second
primary tumor in that time period
o People with one tumor have decent survival rates, and the most common cause of
death from one primary tumor is development of a second primary tumor
o In north America and Europe, HNSCC is most common in middle-aged men who have
been chronic abusers of smoked tobacco and alcohol
 Both alcohol and smoking increase the risk on their own, let alone together
o At least half of oropharyngeal cancers, especially those involving the tonsil, base of the
tongue, and oropharynx, have oncogenic variants of HPV
o HPV-associated tumors have a better outcome than those without HPV
o A family history of a head and neck cancer is a risk factor
o Actinic radiation (sunlight) and pipe smoking predisopose to cancer of the lower lip
o In Asia and India, chewing betel quid and paan predisposes to oral cancer
o Chronic irritation could act as a “promoter” of cancer
o The first change from normal to HNSCC cancer is loss of heterozygosity (LOH) and
promoter hypermethylation that leads to inactivation of p16 – page 747 top pic
 P16 is cyclin-dependent kinase inhibitor (CDKI)
 This change takes you from normal to hyperplasia/hyperkeratosis
o Next is mutation to p53 tumor suppressor gene, which causes dysplasia (CIS)
o Then there is amplification and overexpression of cyclin D1 gene, which activates cell
cycle progression, which now makes it malignant
o Epidermal growth factor (EFGR) is overexpressed in a lot of HNSCC
o Squamous cell carcinomas can arise anywhere in the oral cavity, but its favorites are the
ventral surface of the tongue, floor of the mouth, lower lip, soft palate, and gingiva – p.
747
o In early stages, cancers of the oral cavity appear as either raised, firm, pearly plaques,
or as irregular rough or warty areas of thickening, and both appearances can be
superimposed on leukoplakia or erythroplakia
o Oral cancers don’t need to progress to full-blown dysplasia (carcinoma in situ) before
they are able to invade, unlike cervical cancers (HPV)
o Usually oral cancer spreads to local cervical lymph nodes before it goes anywhere else
o Favorite sites for oral cancer to spread to distantly are the lungs, liver, and bones
Odontogenic cysts and tumors:
o Epithelial lined cysts of the jaw are common – most come from the odontogenic
epithelium in the jaws
o Dentigerous cysts – developmental cyst that originates in the crown of an unerupted
tooth from degeneration of the dental follicle
 Shows single lesions w/ an impacted 3rdmolar (wisdom tooth) on radiograph
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Treat by removing it completely, because if not all of it is removed, it recurs or
can become cancerous
Odontogenic keratocyst (OKC) – developmental cyst that’s locally aggressive and recurs
a lot
 OKCs are most common from age 10-40, more often in guys, and in the
posterior mandible
 They show up on radiograph as radiolucencies
 The cyst is lined with keratinized stratified squamous epthelium
 Again completely remove it, or it commonly recurs
 Multiple OKCs can be a sign that it’s nevoid basal cell carcinoma syndrome
(Gorlin syndrome) from mutations to the tumor suppressor gene PTCH
Periapical cyst – inflammatory cyst that are extremely common at the apex of the teeth
 Periapical cysts develop from chronic inflammation of the tooth pulp, which
can be caused by caries or tooth trauma that leads to inflammation
 The inflammation can cause necrosis of the pulp tissue, which can move
through the length of the root, and exit the apex of the tooth into the
surrounding alveolar bone, causing a periapical abscess
 The inflammation persists from continued presence of bacteria or other
inflammatory causes, so you treat by removing that offense
Odontogenic tumors – tumors from the odontogenic epithelium or ectomesenchyme
 Odontoma – most common type of odontogenic tumor, that comes from the
epithelium and causes depositions of enamel and dentin
The most common problems of the nose are inflammatory diseases, usually as the common cold from a
virus, which can often be complicated by a superimposed bacterial infection (which is more serious)
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Infectious rhinitis (aka common cold):
o Infectious rhinitis is usually caused by a virus, most often adenoviruses, echoviruses,
and rhinoviruses
o Infectious rhinitis causes an inflammatory exudate from the nose (runny nose)
o The nasal mucosa is thickened, edematous, and red
o Nasal cavities are narrowed from enlarged turbinates
o These changes can extend to cause a pharyngotonsillitis
o When there’s a secondary bacterial infection, it enhances the inflammatory rxn and
causes more purulent exudate
o These symptoms eventually clear up within a week
Allergic rhinitis (hay fever) – IgE mediated hypersensitivity rxns to inhaled allergens that affect
1/5 of people
o Allergic rhinitis shows mucosal edema, redness, and mucus secretion, with a WBC
infiltrate involving eosinophils
Recurrent attacks of rhinitis can eventually lead to focal protrusions of the mucosa, called nasal
polyps
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The polyps have edematous mucosa and enlarged glands, infiltrated with WBCs
When there’s no bacterial infection, the mucosal covering of the polyps is intact, the
more chronic they are the more likely they get ulcerated or infected
o Large or several polyps can block the airway and sinus drainage
Chronic rhinitis – when repeated attacks of acute rhinitis, either by infection or allergy, lead to
development of superimposed bacterial infection
o A deviated nasal septum or nasal polyps with impaired drainage increase the chance for
infection
Acute sinusitis – inflammation of the sinuses
o Sinusitis is most often caused by rhinitis, usually by infection from normal oral bacteria
o The inflammatory edema impairs drainage of the sinus, making the exudate build up
and can cause empyema of the sinus
o Obstruction of outflow from the frontal, and less often ethmoid sinuses, can lead to
accumulation of mucous secretions even without bacterial infection, causing a
mucocele
o The acute sinusitis can progress to a chronic sinusitis from normal oral flora
o More severe cases of sinusitis happen usually from fungi, especially in diabetics
o Kartagener syndrome – impaired cilia causes sinusitis, bronchiectasis, and situs inversus
o Infections of the sinus can spread into the orbit, or penetrate into surrounding bone to
cause osteomyelitis or into the cranial vault to cause septic thrombophlebitis
Necrotizing ulcerating lesions of the nose can be caused by fungi (especially mucormycosis in
diabetetics or immunosuppressed), Wegener granlumoatosis, or lymphoma of NK cells infected
with EBV (called lethal midline granuloma or polymorphic reticulosis)
Pharyngitis and tonsillitis are common in a usual viral upper respiratory infection
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The most common causes of pharyngitis and tonsillitis are rhinoviruses, echovirus, and
adenoviruses
Bacterial infection can superimpose over the viral illness, or be a primary infection
The most common bacteria that cause pharyngitis and tonsillitis are group A strep, but it can
sometimes be staph
The inflamed nasopharyngeal mucosa can be covered by an exudative membrane
(pseudomembrane), and the tonsils can be enlarged and covered with exudate
A typical appearance is enlarged, reddened tonsils dotted by spots of exudate, called follicular
tonsillitits
The major importance of strep “sore throats” is from possible development of late sequela, like
rheumatic fever and glomerulonephritis
Tumors in the nose, sinuses, and nasopharynx are rare
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Sinonasal (Scneiderian) papilloma – benign tumors arising from the sinonasal mucosa made of
squamous or columnar epithelium
o Sinonasal papillomas often have HPV 6 or 11 in them
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Raised sinonasal papillomas are most common, but inverted ones are most important
Inverted sinonasal papillomas are benign but locally aggressive tumors of the nose and
paranasal sinuses, that grow into the mucosa (inverted)
o Sinonasal papillomas need completely excised, because it has a high rate of recurrence,
and can invade the eye or cranial vault, or become a carcinoma
Olfactory neuroblastoma (esthesioneuroblastoma) – rare malignant tumors made of small
round cells that resemble neuroblasts, that form lobular nests in the nose near the
neuroendocrine cells of the olfactory mucosa
o The cells are neuroendocrine, so they show granules, and have neuron-specific enolase,
synaptophysin, CD56, and chromogranin
Nasopharyngeal carcinoma:
o 3 patterns of nasopharyngeal carcinoma: keratininzing squamous cell carcinoma,
monkeratinizing squamous cell carcinoma, and undifferentiated carcinomas with lots of
lymphocyte infiltrate, called lymphoepithelioma
o Nasopharyngeal carcinomas are common in Africa, where they’re the most common
cancer in kids, and China, where they’re way more common in adults
 In the US, nasopharyngeal carcinoma is rare
o Risk factors involved with nasopharyngeal carcinoma include EBV, diets high in
nitrosamines, and smoking
o Most undifferentiated and nonkeratinizing squamous cell nasopharnygal carcinomas
show things from the EBV genome, like EBNA-1
o Often primary nasopharyngeal carcinomas are silent, and present when they spread to
cervical lymph nodes
o You treat nasopharyngeal carcinoma with radiotherapy
 Undifferentiated forms respond best to radiotherapy, and keratinized forms
respond the worst
The most common problem in the larynx is inflammation
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Larynx tumors are rare, and can be excised, but that usually changes your voice
Laryngitis – can be from primary infection, allergy, or insult, but more often laryngitis is part of a
generalized upper respiratory tract infection, or from heavy exposure to toxins, like smoking
o Laryngitis can also happen with gastroesophageal reflux (GERD) from the irritation from
gastric stuff
o The larynx can be affected in systemic infections, like tuberculosis or diphtheria
o Most laryngeal infections are self-limited, but some can be serious and cause enough
congestion, exudate, or edema, to obstruct the larynx, especially in kids since they have
small airways
 Especially infection by respiratory syncytial virus, H. flu, or β-hemolytic strep
(group A), which can all induce in kids sudden swelling of the epiglottis and
vocal cords that can be fatal if not treated as an emergency and quickly fixed
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This is less common in adults because their larynx is bigger and they have
stronger accessory muscles
o Croup – laryngotracheobronchitis in kids, that causes inflammatory narrowing of the
airway to cause the classic inspiratory stridor (harsh barking cough)
o The most common form of laryngitis is seen in heavy smokers, and predisposes to
squamous epithelial metaplasia, which can lead to carcinoma
Reactive nodules (aka polyps) can develop on the vocal cords, most often in heavy smokers or
people who use their vocal cords a lot (like in singers, aka singer’s nodules) – p. 752 bottom pic
o Classically, singer’s nodules are bilateral, and polyps are unilateral
o Reactive nodules are most common in men, and look like smooth, rounded raised
lesions covered by squamous epithelium, and has a core of loose myxoid connective
tissue
o Because of where they are and the inflammation they cause, reactive nodules
characteristically change the voice and often cause progressive hoarseness
o Reactive nodules basically never give rise to cancer
Laryngeal squamous papillomas – benign tumors usually in the true vocal cords that form soft,
“raspberry-like” raised lesions
o The papillomas are made of finger-like projections with central fibrovascular cores
covered by stratified squamous epithelium
o When the papillomas are on the free edge of the vocal cord, trauma can lead to
ulceration that can cause hemoptysis
o Papillomas usually happen single in adults, but multiple in kids (juvenile laryngeal
papillomatosis
o The papillomas are caused by HPV types 6 and 11
o Papillomas don’t become malignant, but often recur, and they commonly spontaneously
regress at puberty
Carcinoma of the larynx – page 752 and 753
o Carcinoma of the larynx progresses like other carcinomas from hyperplasiaatypical
hyperplasiadysplasiacarcinoma in situinvasive carcinoma
o The carcinoma looks either like smooth white or red focal thickenings with keratosis, or
like ulcerated white-pink lesions
o The likelihood of developing carcinoma from a hyperplasia of the vocal cords depends
on the level of atypia when the lesion is first seen
 Orderly hyperplasias have almost no risk for malignant transformation, but the
risk increases for mild dysplasia and more for severe dysplasia
o The changes to the vocal cords are usually from tobacco smoke, and often up until it
becomes cancerous, the epithelial changes will regress if you quit smoking
o Alcohol also increases the risk for laryngeal cancer, and alcohol and smoking together
greatly increase the risk for laryngeal carcinoma
o Most (95%) of laryngeal carcinomas are typical squamous cell tumors
o Intrinsic laryngeal carcinomas are those confined within the larynx, and extrinsic ones
are those that extend outside the larynx
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The squamous cell carcinomas of the larynx grow just like other squamous cell
carcinomas: they start as in-situ lesions that later look like pearly gray, wrinkiled plaques
on the mucosal surface, ultimately ulcerating and fungating – page 753
Because the cancer is from an environmental carcinogen, it’s common for other nearby
tissue to show hyperplasia or dsyplasias
Carcinoma of the larynx presents as persistent hoarseness
 Usually at presentation over half of them are confined to the larynx, and have
better prognosis than those that spread into nearby stuff
Later, the laryngeal tumor can cause pain, dysphagia, and hemoptysis
They’re extremely vulnerable to secondary infection of the ulcerating lesion
1/3 of people with laryngeal carcinoma die, usually from infection of the distal
respiratory airway, or widespread metastases and cachexia
The most common problem of the ear is otitis, usually involving the middle ear and mastoid
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Otitis media – inflammation of the middle ear, happens most often in kids
o Otitis media is usually viral and makes a serous exudate, which can turn suppurative if
there’s secondary bacterial infection
o The most common bacteria are strep pneumonia, H flu, and Moraxella catarrhalis
o When there’s frequent bouts of acute otitis media that doesn’t resolve, it’s chronic,
which is usually caused by pseudomonas aeruginosa, staph areus, or a fungus
o Chronic otitis can perforate the eardrum, encroach on the ossicles or labyrinth, spread
into the mastoid spaces, or penetrate into the cranial vault to cause temporal cerebritis
or abscess
o Otitis media in people with diabetes, especially when caused by pseudomonas
aeruginoas, is very aggressive and spreads widely causing destructive necrotizing otitis
media
Cholesteatomas – cysts lined be keratinzing squamous epithelium or metaplastic mucussecreting epithelium, filled with debris from desquamated epithelium and sometimes spicules
of cholesterol
o Cholesteatomas are usually caused by otitis media
o Chronic inflammation and perforation of the eardrum with ingrowth of the squamous
epithelium or metaplasia of the secretory epithelial lining of the middle ear, lead to
formation of a squamous cell nests that becomes cystic
 A chronic inflammatory rxn surrounds the keratinous cyst
o Sometimes the cyst ruptures, increasing the inflammatory rxn and inducing formation of
giant cells that enclose the necrotic squames and debris
o Cholesteatomas progressively enlarge to erode into the ossicles, labyrinth, nearby bone,
or surrounding soft tissue, and can sometimes result in a visible neck mass
Otosclerosis – abnormal bone deposition in the middle ear about the rim of the oval window
where the foot of the stapes meets it
o Usually both ears are affected
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Bony overgrowth anchors the stapes onto the oval window
The degree of immobilization determines how severe the hearing loss is
Otosclerosis usually starts early in life, and minimal effects of it are extremely common
in young to middle aged adults
 More severe symptoms of otosclerosis though are rare
o Most of the time, otosclerosis is familial, and is slowly progressive over decades,
leading to eventual hearing loss
Tumors of the ear are rare, except for basal cell or squamous cell carcinomas of the pinna
(external ear)
o Most common in elderly men from actinic radiation (sun exposure)
o Ear tumors in the canal are usually squamous cell carcinomas, which are more common
in older women, and rarely spreads
Neck lesions:
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Branchial cyst (cervical lymphepithelial cyst) – benign cysts usually on the upper lateral of the
neck along the sternocleidomastoid (SCM)
o Most branchial cysts arise from remnants of the second branchail arch, and often seen
in young adults between ages 20-40
o The cysts are well circumscribed, with fibrous walls usually lined by stratified squamous
or pseudostratified columnar epithelium
o The cyst wall usually has lymph tissue with germinal centers
o The cysts enlarge slowly, or rarely turn malignant, and are easily excised
Thryoglossal duct cyst – remnants of the descent of the thyroid during development
o In embryo, the thyroid starts in foramen cecum at the base of the tongue, and then it
descends to ifs final location in the anterior neck
Paraganglioma – rare tumors of paraganglia
o Paraganglia – clusters of neuroendocrine cells associated with the symps and parasymps
o So paragangliomas can happen throughout the body where these paraganglia are
o The most common spot for a paraganglioma is the adrenal medulla, where they cause a
pheochromocytoma, but the most common spot for them outside the adrenals is the
head and neck
o Paravertebral paraganglia tumors have symp connections and are chromaffin positive,
which is a stain for catecholamines
o Another spot for them is the paraganglia in the great vessels of the head and neck
(aorticopumonary chain) – most often in the carotid bodies at the bifurcation of the
common carotid artery
 These ones are parsymp paragangliomas, made of nests (Zellballen) of round
chief cells with eosinophilic cytoplasm
 The chief cells stain well with neuroendocrine markers like chromogranin,
synaptophysin, or enolase
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There’s also a supporting network of spindle-shaped stroma called
sustenticular cells, that are positive for S-100 protein
Carotid body tumors are slow-growing painless masses that arise in your 50’s60’s
Half are fatal because they have infiltrative growth
There are 3 major salivary glands – parotid, submandibular, and sublingual
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Xerostomia – dry mouth from decrease in making of saliva
o Xerostomia is a major feature of the autoimmune problem Sjogren syndrome, and in
radiation therapy
o Xerostomia is most often caused by drugs, like anticholinergics,
antidepressants/antipsychotics, diuretics, antihypertensives, sedatives, muscle
relaxants, analgesics, and antihistamines
o You’ll see dry mucosa, and possible atrophy of the papillae of the tongue, with fissuring
and ulcerations
o Xerostomia can lead to increased rates of dental caries, candidiasis, and difficulty
swallowing and speaking
Sialadenitis – inflammation of the salivary glands
o The most common type of inflammatory salivary gland lesion is mucoceles
 Mucoceles happen from either blockage or rupture of a salivary gland duct,
causing leaking of saliva into the surrounding connective tissue stroma
 Mucoceles are most common on the lower lip, and happen from trauma, so
they’re often seen in kids, young adults, and old people – page 757 top left pic
 Mucoceles look like swelling of the lower lip w/ a blue translucent hue to them
 The mucocele is a cystlike space lined by inflammatory granulation tissue, filled
with mucin and inflammatory cells, especially macrophage
 You treat by completely excising it, and if you don’t get it all it recurs
 Ranula – mucocele from when the duct of the sublingual gland is damaged
o The most common form of viral sialdenitis is mumps, especially in the parotids
o The most common autoimmune cause of inflamed salivary glands is Sjogren’s
syndrome, causing xerostomia
o Bacterial sialadenititis is common, especially in the submandibular glands, usually due to
obstruction of salivary ducts by a stone (sialolithiasis)
 The common bugs are staph aureus and strep viridans
 Stone formation can be related to obstruction of the opening of the salivary
duct by food debris, edema, or injury
 Dehydration and decreased secretory function can predispose to secondary
bacterial invasion
 Especially causing parotitis in old people or those with recent thoracic
or abdominal surgery
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The obstruction and bacteria cause inflammation of the salivary gland, usually
since it’s just that gland its unilateral
Salivary gland tumors – page 757 bottom table
o Salivary gland tumors are uncommon (tell that to dad)
o Most (65%-80%) arise in the parotid, 10% in the submandibular glands
o 15%-30% of tumors in the parotid glands are malignant, 40% of submandibular gland
tumors are malignant, half of minor salivary gland tumors, and most (70-90%) of
sublingual tumors are cancerous
 So the chance of the tumor being malignant decreases the bigger the gland is
o Salivary gland tumors usually happen in adults, with benign tumors most often
happening in your 50’s-70’s, and malignant ones happening later in life
o Parotid gland tumors show up as swellings in front of and below the ear
 They’re mobile on palpation unless they’re malignant
o The benign tumors are usually around for months to years before getting noticed, while
the cancers demand attention sooner from rapid growth
o Pleomorphic adenomas (mixed tumors) – benign tumors that have a ton of diversity in
how they can look on histo – page 758
 Half of benign salivary gland tumors are pleomorphic adenomas (mixed tumors)
 They’re 60% of parotid tumors
 Pleomorphic adenomas have a mix of ductal (epithelial) and myoepithelial cells,
so they show both epithelial and mesenchymal differentiation
 So there’s epithelial stuff and then hyaline, cartilage, or bone tissue
 Radiation exposure increases the risk for pleomorphic adenomas
 It’s thought pleomorphic adenomas come from either myoepithelial or ductal
reserve cells
 Pleomorphic adenomas are encapsulated, but may not be totally, so they can
protrude into the surrounding gland
 The tumor is gray-white with myxoid and blue translucent areas of chondroid
(cartilage)
 The epithelial parts look like salivary duct cells
 The duct parts are then in a mesenchyme background of loose myxoid tissue
that has islands of cartilage and sometimes bone
 Usually there is no epithelial dysplasia or mitotic activity
 Pleomorphic adenomas present as painless, slow-growing, moveable masses in
the parotid or submandibular areas, or in the buccal cavity – page 758
 The recurrence rate of pleomorphic adenomas from parotidectomy is about 4%
 If the pleomorphic adenoma develops a carcinoma inside it, it’s called
carcinoma ex pleomorphic adenoma, or a malignant mixed tumor
 Tumors there for less than 5 years have about 2% chance of developing
a malignancy, while it’s 10% for those that’ve been there over 15 years
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The malignant form is very aggressive, with a mortality rate of 1/3-half
within 5 years
Warthin tumor (papillary cystadenoma lymphmatosum) – benign tumor that shows up
almost always in the parotid gland – page 759
 It’s the second most common salivary tumor, and happens more in guys usually
in their 50’s-70’s
 Smokers have a huge increased risk for developing a Warthin tumor
 Warthin tumors are round encapsulated masses in the parotid, that are easy to
palpate, and have a pale gray surface with narrow cystic or cleft-like spaces
filled with a mucinous or serous secretion
 The spaces are lined by a double layer of neoplastic epithelial cells, with the
surface being columnar cells with granular eosinophilic cytoplasm, and the
bottom layer being cuboidal cells
 Oncocytes – epithelial cells stuffed with mitochondria that cause the granular
appearances to the cytoplasm
Mucoepidermoid carcinoma – tumors that are a mix of squamous and mucus-secreting
cells, that are the most common primary malignant tumor of the salivary glands
 Mucoepidermoid carcinoma is 15% of all salivary gland tumors, and happen
mostly (60-70%) in the parotids, but are also a large fraction of tumors in other
salivary glands – page 760
 Often, mucoepidermoid carcinoma has a chromosome translocation that
creates a fusion gene made of MECT1 and MAML2 genes
 Low grade mucoepidermoid carcinomas invade locally and recur sometimes, but
rarely metastasize and so have a good survival rate
 Intermediate and high-grade mucoepidermoid carcinomas are invasive and hard
to excise, so the recur ¼-1/3 of the time, and 1/3 metastasize, and only half live
5 years
Adenoid cystic carcinoma – rare tumor that half the time is in the minor salivary glands,
especially in the palate
 They’re gray-pink lesions that are slow growing but tend to invade neural
spaces, and are stubbornly recurrent
 Half or more spread to distant sites, which can take many years to develop the
secondary tumor, so initial survival is good, but at 15 years it drops
 Tumors of the minor salivary glands have a worse prognosis usually than in the
parotids