PATHOLOGY OF THE EAR
1) PATHOLOGY OF EXTERNAL EAR: consists of the auricle and the
external auditory meatus- lined by squamous epithelium with waxsecreting ceruminous glands
A- Inflammatory and other non-neoplastic disorders:
1- preauricular sinus -is a developmental disorder caused by abnormal
fusion of facial folds
-presents as blind-ending epithelium-lined cyst near the external meatusinfection may cause abscess formation
2- idiopathic pseudocystic chondromalacia- occurs mainly in young and
middle-aged adults, grossly- localized swelling of the auricular cartilage- well
defined cavity in cartilage- which contains a yellowish fluid, origin is unknown,
maybe traumatic
3- diffuse external otitis –this is a common condition, most frequently
associated with pseudomonas aeruginosa or fungi (aspergillus)- acute suppurative
inflammation of the external auditory canal -foreign body predisposes to
infection
4-chondrodermatitis nodular chronica helicis - common lesion, clinically
characterized by painful nodule in the helix, mimicking the tumor
histologically: ulceration of the skin of the auricle with necrosis of the cartilage
and inflammatory infiltrate in perichondrium, origin is unknown, maybe it results
from a trauma
-histologically: ulceration of the skin, chronic infiltration involving the
perichondrium and the underlying cartilage
5- keratin granuloma- common condition, occurs when keratin squames
become implanted into the deeper tissues of the auricle foolowing trauma
-granuloma contains giant foreign-body type multinucleated cells
B-Tumors of external ear
-benign neoplasms arising from ceruminous glands: adenoma or pleomorphic
adenoma arising in ceruminous glands are rare
-bony lesions- include osteoma, fibrous dysplasia and exostosis
-nevocytic nevi occur in the skin of the auricle
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-malignant neoplasms of external ear include skin lesions, such as basal cell
carcinoma and squamous cell carcinoma (in old persons- sun exposed skin)common
melanoma is unusual in the external ear
2) PATHOLOGY OF MIDDLE EAR
Inflammatory lesions:
1 acute and chronic otitis media –otitis media is one of the most common
diseases of the ear, particularly in children, the disease is usually caused by
haemophilus influenzae, streptococcus pyogenes and pneumococcus
-characterized by acute or chronic suppurative inflammation of the middle ear -usually in small children as a complication of acute viral or bacterial pharyngitis
-acute otitis media- is characterized by edema, congestion and abundant
purulent exudate- tympanic membrane may rupture- clinical presentationpurulent discharge from the ear, associated with severe pain and fever
-chronic otitis media- is associated with necrosis caused by bacterial
infections, there is also marked congestion and hemorhage, because of poor
lymphatic drainage of the middle ear, old hematoma becomes converted to
cholesterol granuloma with hemosiderin deposits and foreign body giant cells
-chronic suppuration with fibrosis of ossicles can lead to progressive hearing
loss -often associated with proliferation of the middle ear mucosa and its
glandular metaplasia, ingrowth of keratinizing squamous epithelium forming socalled cholesteatoma
2- cholesteatoma- is the presence of stratified squamous epithelium in
high quantities in middle ear, composed of keratinized debris and inflammatory
cells
-granulation tissue in the middle ear may protrude from the external auditory
meatus as so-called
3- inflammatory polyp (otic/ aural polyp)
arises in the middle ear on the basis of chronic otits
microscopically, it consists of inflammatory granulation tissue -histologically
composed of nonspecific granulation tissue
severe complications may result from spread of the infection to masoid bone:
4-mastoiditis- localized bone infiltration and destruction (osteomyelitis
of mastoid bone)
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-meningitis and brain abscess formation -caused by spread of infection from
the middle ear into the cerebral cavity
-thrombophlebitis of the venous sinuses
-characterized by severe headache, fever and bacteriemia
-septic embolisation may result in development of lung abscesses
5- otosclerosis
-is a disease of uncertain origin, characterized by sclerosis of the middle ear
ossicles- increased bone density, abnormal bone trabeculae formation, bony
ankylosis, it is also a disease of bone labyrinth (inner ear)
-results in impaired transmission of sound waves and loss of hearing
-disease is bilateral, strong familial tendency - autosomal dominant inheritance is
likely
-progressive deafness-beginning in 3rd decade
TUMORS AND TUMOR-LIKE CONDITIONS OF MIDDLE EAR
1-choristoma, salivary gland, sebaceous and glial types
-choristoma is a developmental disorder resembling tumor composed of tissues
not normally present at the site
-choristomas occasionally seen in middle ear-composed of one or three types of
tissue, such as salivary gland, glial, and sebaceous
2- middle ear adenoma
-is the commonest tumor of middle ear
-well circumscribed white firm tumor, sometimes ossiclec can be entrapped in
the tumor mass and may even show destruction
microscopically adenoma is formed by small glands with back to back appearance,
composed of small uniform cuboidal cells with abundant acidophilic cytoplasm,
neurosecretory granules are sometimes present in the cytoplasm, mucinous
differentiation is frequent
prognosis- is excellent, only rare cases with local recurrences
3- jugulotympanic paraganglioma
-most jugulotympanic paragangliomas arise from the paraganglion situated in the
wall of jugular vein- these tumors have been referred to as jugular
paragangliomas (glomus jugulare tumors)
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-minority arise from the paraganglion situated to middle ear surface- these
tumors have been referred to as tympanic paragangliomas (glomus tympanicum
tumor)
clinically: the typical presentation is that of red mass protruding behind the
tympanic membrane - the tumor erodes middle ear- may extend into the
external canal- may cause bleeding, deafness
- locally aggressive, causes destruction of the bone, no metastases, local
recurrence- about 50%
histologically: highly vascular tumor, composed of solid nests of very regular
small rounded tumor cells
4- squamous cell carcinoma
-uncommon in middle ear, typically present in older patients with long-standing
ear discharge, associated with pain, bleeding and facial palsy, and conductive
hearing loss
malignant locally aggressive tumor
3) PATHOLOGY OF the INNER EAR
-acute viral or bacterial infection of inner ear
is rare, may cause acute loss of hearing
-Meniere's disease (hydrops of the labyrinth)
-uncommon lesion involving the inner ear, cause is not known
clinically: fluctuating hearing loss, attacks of sensation of fullness of the ear,
episodic vertigo and vomiting
morphology: characterized by imbalance between secretion and absorption of
endolymphatic fluid with accumulation of the fluid in the inner ear- increased
endolymphatic pressure
TUMORS OF THE INNER EAR
-1- acoustic neuroma
-the most common tumor of inner ear and vestibular system- this is simple
example of benign peripheral nerve tumor- neurilemmoma arising in eighth or
seventh cranial nerve -biologically benign
-sometimes may be associated with Recklighausen disease
2- Heffner tumor (LG adenocarcinoma of probable endolymphatic sac
origin)
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very rare tumor of inner and middle ear, of bland histomorphology, with
aggressive behaviour
-some cases are associated with von Hippel-Lindau disease
-in most cases, the tumor has papillary and glandular appearance, composed of
highly vascularised papillae lined by single layer of cuboidal bland epithelium
PATHOLOGY OF THE EYE
major structural components include: optic nerve- main nerve- carries visual
impulses from the retina to the brain
-anterior covering of the eyeball is the translucent cornea- permits entry
of the light into the eyeball- cornea is continuous with the sclera
-the conjuctiva lines the inner surface of the eyelids- and is reflected
onto the sclera
-the tears are secreted by the lacrimal glands- situated in the lateral part
of the orbit
the function of the eye- involves perception of images in the retina- converted
to electric impulses- that pass to the visual cortexoptic pathway includes - optic nerves, chiasm, lateral geniculate body, and optic
radiation
Clinical manifestations of eye disease
-pain- occurs in many diseases, such as conjunctival inflammation,
inflammation of the uveal tract, glaucoma, headache may accompany conditions
of disturbed vision
-visual disturbances- spots and halos before the eyes occur in early
cataract
halos may occur in glaucoma, diminution of the visual field- signifies disease of
the retina, the optic disk or the visual neural pathways
-night blindness- results from vitamin A deficiency
-double vision (diplopia)- feature of eye muscle dysfunction
-discharge- eye discharge may represent increased tearing or
inflammation of the conjuctiva
-changes in appearance- strabismus- caused by muscle imbalance,
hemorrhages, congestion, jaundice, swelling, displacement of the eye such as
proptosis-forward displacement
 Pathology of eyelids
- sty (hordeolum)-is an acute suppurative inflammation of the hair follicle
or associated glandular structures- the glands of Zeis and the apocrine glands of
Moll
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-caused by Staphyloccocus aureus- painful localized abscess
-chalazion- is a common inflammatory process involving the meibomiam
sebaceous glands- is believed to be caused by duct obstruction- retention of
secret, infection and chronic inflammatory infiltration by macrophages,
lymphocytes and plasma cells
-clinically- it produces an indurated mass that may be mistaken for a tumor
-xanthelesma- is a small yellow plaque composed of collections of lipidladen foamy macrophages, occurs often in diabetes- usually multiple lesions that
affect both eyes
-tumors basal cell carcinoma- is the commonest malignant tumor of the eyelids
-the tumor begins as small nodule in th epidermis of the eyelid, slowly growing
histologically is composed of the nests of small basophilic cells resembling the
basal layer of the epidermis
-the tumor is locally invasive aggressive, but low if any tendency for metastases
 meibomiam gland carcinoma- sebaceous carcinoma- occurs very rarely, slowly
growing tumor- first may resemble chalazion- yellow colour
histologically-composed of large cells with abundant vacuolated clear cytoplasmcontain lipid vacuoles, more locally aggressive behavior- lymph node metastases
common
 Pathology of the conjuctiva and cornea.
- conjuctiva is lined by a thin transparent nonkeratinizing stratified
epithelium
-(kerato)conjuctivitis- inflammation of the conjuctiva and cornea
conjuctivits is common and has many causes
-most common- acute bacterial- characterized by pain, hyperemiaappearing as red eye, and purulent discharge- numerous neutrophilic leukocytes
-viral conjuctivitis- most frequently caused by adenoviruses and
herpes simplex virus
-swimming pool conjuctivitis- is common worldwide, characterized by
acute inflammation with pain, red eye, discharge and histologically by
accumulation of lymphocytes, it is caused by chlamydia,
-trachoma- is a much more serious chlamydial infection in which
there is long-term destruction of the cornea- leads to blindness if left
untreated, trachoma is the commonest cause of blindness in the world
-allergic conjuctivitis- is typically seasonal in occurrence due to
pollens in environment and is associated with hay feverhistologically-infiltration by lymphocytes and eosinophils, goblet cell hyperplasia
 tumors of the conjuctiva- benign include many tumor types, such as
papilloma, melanocytic nevi, hemangioma, neurofibroma
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malignant include more often tumors such as squamous cell
carcinoma- rare, most cases are believed to result from long-term exposure to
sun shine, carcinoma invades superficially, never metastasizes, excellent
prognosis- is treated by wide local excision
 malignant melanoma- is rare, prognosis is related to the depth of
invasion
 Pathology of orbital soft tissues
-inflammatory pseudotumor- is characterized by protrusion of the
eyeball- pain, swelling and restriction of eye movements
histologically-edema, hyperemia, infiltration of the orbital soft tissue with
mixed inflammatory infiltrate- cause is unknown
-Graves disease- is a primary autoimmune hyperthyroidism- commonly
associated with exophtalmus- results from edema and accumulation of
mucopolysaccharides in the orbital soft tissue, the orbital muscles show marked
myxoid change and weakness
-the eyeball is displaced forward- proptosis
 Pathology of the eyeball
- the eyeball is composed of several layers- retina- is the inner light-sensitive
layer- composed of modified neurons, the axons of which form the optic nerve
-choroid- is pigmented, and sclera-is fibrous- are outer layers
-the lens-is attached to the sclera by cilliary muscle- which controls the focal
length of the lens
-acute endophtalmitis- is a acute inflammations of the eyeball, often
caused by pyogenic bacteria- swelling and severe leukocytic infiltration
-if untreated leads to severe destruction with softening and collapse of the
eyeball- phtisis bulbi
-toxoplasma chorioretinitis- caused by toxoplasma gondii- infection
involves the retina and the choroid- may be congenital or acquired
-congenital toxoplasmosis-may cause neonatal death from encephalitis, or
chorioretinitis
-acquired toxoplasmosis- occurs in adults, ocular involvement is commongranulommatous inflammations and fibrosis
-cataract- is a degenerative condition of the eyeball, characterized by
loss of transparency of the lens
pathologically- the epithelial cell break down, fragment and undergo dissolution
clinically- progressive loss of vision, halos and spots in the visual field are
common symptoms
treatment- removal of the cataract and replacement with arteficial lens
-glaucoma-is defined as an increase in intraocular pressure sufficient to
cause degeneration of optic disk and optic nerve fibers
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-glaucoma results from abnormal circulation of aqueous humor- it is produces by
cilliary body-the fluid then passes from the posterior chamber through the pupil
to the anterior chamber- then peripherally to the angle between the iris and
cornea
-glaucoma is a common disorder, visual loss is the most common effect
-retrolenticular fibroplasia of prematurity- is caused by excessive oxygen
therapy- in immature infants treated for respiratory distress syndrome
-retinal detachment- is separation of the neuroepithelial layer of the
retina from the pigmented layer due to either fibrous contraction or to fluid
collection
clinically- retinal detachment causes sudden loss of part of the field of vision
-tumors of the eyeball malignant melanoma-rather common in the uveal tract- choroid, cilliary body,
iris
-highly malignant tumor, poor prognosis
 retinoblastoma- malignant tumor of the retina, occurs in two forms, as
inherited and sporadic, occurs exclusively in children
-inherited- autosomal dominant trait- 90% penetrance, the patients commonly
have bilateral retinoblastoma
-sporadic cases- unilateral
pathology- retinoblastoma arises in the retina- from primitive neural cellsaggressive malignant tumor- hematogenous spread is possible
histologically- composed of small undifferentiated cells with a high nucleoplasmatic ration, mitoses frequent
clinically- rapid death without treatment, tumor can be treated by radiation and
chemotherapy, up to 2 % of tumor undergo spontaneous regression
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