Last revised 28 May 2008
Copyright (c) 2004-2008, PathologyOutlines.com, Inc.
Bold and underlined topics are hypertext links and may open a new window
Table of contents
Primary references, normal anatomy, normal histology
Congenital anomalies: general, accessory tragi, first branchial cleft anomalies, heterotopia/choristoma
Inflammatory/infectious/autoimmune/systemic disorders: angiolymphoid hyperplasia with eosinophilia, chondrodermatitis nodularis chronica helicis, gout, granuloma inguinale, idiopathic auricular ossificans, idiopathic cystic chondromalacia of auricular cartilage, inflammatory aural/otic polyp, Kimura’s disease, labyrinthitis, malakoplakia, Meniere’s disease, myospherulosis, necrotizing “malignant” external otitis, otitis media, otosclerosis, Paget’s disease, pneumocystis, presbycusis, relapsing polychondritis, Wegener’s granulomatosis
External ear tumors-benign/non-neoplastic: amyloid nodules, atypical fibroxanthoma, ceruminal gland adenoma, cholesteatoma, collagenous papules, elastotic nodules, exostosis, keloid, keratinous cyst, keratoacanthoma, keratosis obturans, myofibromatosis, myxoma, neurothekeoma, osteoma, solitary fibrous tumor, synovial chondromatosis
External ear tumors-malignant: basal cell carcinoma, ceruminal gland adenocarcinoma, malignant blue nevus, melanoma, metastases, squamous cell carcinoma
Middle ear, inner ear and temporal bone tumors-benign/non-neoplastic: acoustic neuroma, cholesteatoma, chondroblastoma, jugulotympanic paraganglioma, lipochoristoma, lipoma, meningioma, middle ear adenoma, papilloma
Middle ear, inner ear and temporal bone tumors-malignant: adenocarcinoma, aggressive papillary tumor, chondrosarcoma, giant cell tumor, Langerhans cell histiocytosis, lymphoepithelioma-like carcinoma, malignant peripheral nerve sheath tumor, metastases, osteosarcoma of skull, rhabdomyosarcoma, squamous cell carcinoma
Miscellaneous: TNM staging, grossing
Primary references for Ear chapter
American Journal of Clinical Pathology (AJCP), May 1975 to December 2006
American Journal of Surgical Pathology (AJSP), March 1977 to December 2006
Archives of Pathology and Laboratory Medicine (Archives), January 1976 to October 2006
Human Pathology (Hum Path), March 1970 to November 2006
Journal of Clinical Pathology (J Clin Path), January 1975 to November 2006
Modern Pathology (Mod Path), January 1988 to December 2006
Rosai, J: Ackerman’s Surgical Pathology (9th Ed); Mosby, 2004
Sternberg,
S: Diagnostic Surgical Pathology (4th Ed); Lippincott Williams & Wilkins,
2004
Journal search
terms: ear, auditory, temporal bone
Please refer to these primary references for more detailed discussions and photographs
Normal anatomy of ear
Sense organ for hearing and balance
Divided into external ear, middle ear and temporal bone, and inner ear
External ear conducts sound vibrations to tympanic membrane; middle ear conducts sound to auditory portion of inner ear
External ear
Consists of pinna (auricle) leading into external auditory canal, which ends at tympanic membrane
Pinna: develops from fusion of auricular hillocks, themselves from first and second branchial areas; helix is prominent rim; antihelix is prominence that is parallel with and in front of helix
External auditory canal: S shaped passage, 2.5 cm long, develops from remnant of first branchial groove; has outer cartilaginous portion and inner osseous portion
Tympanic membrane: develops from first and second branchial pouches and first branchial groove
Drawings: lateral surface of pinna #1; #2; external and middle ear #1; #2; #3; external, middle and inner ear #1; #2; tympanic membrane
Middle ear
Also called tympanic cavity
Filled with air (via eustachian tube); contains chain of movable bones which convey vibrations communicated to tympanic membrane across the middle ear cavity to the internal ear
Lateral aspect is tympanic membrane and squamous portion of temporal bone
Medial aspect is petrous portion of temporal bone
Superior aspect is tegmen tympani, a thin plate of bone separating middle ear space from cranial cavity
Inferior aspect is thin plate of bone separating tympanic cavity from superior bulb of internal jugular vein
Anterior aspect is thin plate of bone separating tympanic cavity from carotid canal containing internal carotid artery
Posterior aspect is petrous portion of temporal bone, containing mastoid air cells and mastoid antrum
Develops from invagination of first branchial pouch (pharyngotympanic tube) from primitive pharynx
Contains auditory ossicles (malleus, incus, stapes), eustachian tube, tympanic cavity, epitympanic recess, mastoid cavity, chorda tympani of facial nerve (cranial nerve VII)
Malleus and incus develop from mesoderm of first branchial arch (Meckel cartilage), stapes develops from mesoderm of second branchial arch (Reichert cartilage)
Connects to pharynx through Eustachian tube
Connects with mastoid cavity through contiguous pneumatic spaces
Drawings: tympanic membrane; inner wall of middle ear #1; #2; eustachian tube; chain of ossicles #1; #2; malleus; incus; stapes; temporal bone
Inner ear
Located in medial (petrous) portion of temporal bone
Contains cochlea (sense organ for hearing) and vestibular labyrinth (sense organ for balance with membranous and osseous portions), and internal auditory canal (contains vestibulocochlear nerve, CN VIII)
Vestibular labyrinth contains semicircular canals, includes blind endolymphatic sac, located in petrous bone
Endolymphatic sac is connected to utricle and saccule by endolymphatic duct, which passes along petrous bone
Develops before middle and external ear, at end of first month of gestation
Drawings: labyrinth #1; #2; #3; #4; cochlea and surrounding structures; cochlea cross section; floor of cochlea; spiral organ of Corti #1; #2; semicircular canal cross section; endolymphatic sac (see inset); endolymphatic sac (ES) and duct (ED)
References: Wikipedia (cochlea)
External ear
Pinna: resembles skin elsewhere, with keratinized, stratified squamous epithelium, dermal adnexal structures, subcutaneous fibroconnective tissue, fat and elastic fibrocartilage which provides support
External auditory canal: lined by thin keratinized stratified squamous epithelium covering scant fibrous stroma along entire canal and covering external tympanic membrane
Outer third contains ceruminous glands (modified apocrine glands) deep within dermis that produce cerumen; glands are in clusters of cuboidal cells with intensely eosinophilic cytoplasm with apical snouts and containing golden-yellow, granular pigment and secretory droplets along luminal border; glands are surrounded by myoepithelial cells; outer canal contains cartilage not bone
Inner two thirds has very thin epidermis which lacks rete pegs, no/reduced number of ceruminous glands and dermal adnexa; contains bone not cartilage
Cerumen: watery fluid devoid of lipids; drains from glands into ducts, which open into hair sacs of ear canal hairs; fluid mixes with sebaceous gland secretions to produce cerumen (wax)
Tympanic cavity: thin fibrous structure lined by attenuated keratinizing squamous epithelium on external canal side
Micro images: elastic cartilage (elastic stain)
Virtual slides: pinna of ear
Middle ear
Eustachian tube: respiratory epithelium that becomes pseudostratified as it approaches nasopharynx; lymphoid component, prominent in children, is called Gerlach tubal tonsil; no glands
Tympanic membrane: thin fibrous structure lined by flat, single layer of cuboidal epithelium on middle ear side
Mastoid: flat, single, cuboidal epithelium
Ossicles: typical synovial joints
Inner ear
Vestibular labyrinth is lined by flat to low columnar epithelium overlying vascular stroma
Micro images: cochlea; hair cells (mammalian)
Congenital anomalies of ear
Congenital anomalies of ear-general
Common (1 per 6000 births); higher incidence in Japanese and Navajo Indians
More common in males
90% are unilateral
Either isolated or with other abnormalities
Cosmetic or functional
Anotia: complete absence of external ear
Microtia: mild to severe deformity; associated with other defects
References: inner ear malformations, University of Alabama
Also called accessory or supernumerary ear, accessory auricle, polyotia
Appears at birth; incidence of 0.2 to 0.5%
May be related to second branchial arch anomalies
Usually no associated hearing loss or anomalies (Int J Pediatr Otorhinolaryngol 2002;63:25)
Associated in some cases with cleft lip/palate, mandibular hypoplasia, oculoauriculovertebral dysplasia (Goldenhar syndrome, OMIM 164210)
Solitary or multiple, unilateral or bilateral, sessile or pedunculated, soft or cartilaginous
Treatment: simple excision
Gross: skin covered nodule, often anterior to auricle
Gross images: accessory tragus #1; #2, #3
Micro: skin with cutaneous adnexae and central cartilage (resembles normal external auricle)
Micro images: various images
DD: squamous papillomas (no cartilage, no adnexae)
First branchial cleft anomalies of ear
Cysts, sinuses, abscesses (Emerg Med J 2003;20:103), and fistulas near external ear; may be pre-, post- or infraauricular; also at angle of jaw, ear lobe, in external auditory canal or parotid gland
Fistulas may connect skin with external auditory canal
Includes duplication of external auditory canal (Int J Pediatr Otorhinolaryngol 2005;69:255)
1-8% of branchial defects
Usually middle aged women
Classified by Work as Type I or II (Laryngoscope 1972;82:1581)
Type I: keratinizing squamous epithelium without adnexae (ectoderm only, duplicates membranous external auditory canal)
Type II: keratinized squamous epithelium with adnexa and cartilage (ectoderm and mesoderm, duplicates external auditory canal and pinna)
Treatment: excision; often recurs
References: Baylor College of Medicine, branchial anomalies
Heterotopia / choristoma of ear
See also Lipochoristoma
WHO classification includes salivary gland choristoma and glial choristoma
Heterotopia: mass of tissue normal to the site in abnormal location
Choristoma: mass of tissue foreign to the site
Hamartoma: mass of tissue normal to site in haphazard arrangement
Middle ear choristomas include salivary gland tissue and neuroglial tissue
Salivary gland choristomas usually occur in women, associated with facial nerve and ossicle anomalies, suggesting a second branchial arch developmental anomaly; have mucinous and serous elements similar to submandibular and sublingual glands
Neuroglial choristomas are often actually an acquired encephalocele with herniation of brain into middle ear and mastoid; treatment is surgical, although tissue may adhere to facial nerve; determine relationship to CNS structures at operation or radiographically, not by histology (Laryngoscope 2000;110:1731, Ann Diagn Pathol 2004;8:252)
Cartilaginous choristoma of external ear canal: may be relatively common (Otolaryngol Head Neck Surg 2005;133:786)
Case reports: salivary gland tumors of middle ear (Archives 1982;106:39, Laryngoscope 2006;116:1033), glial choristoma of middle ear and mastoid bone (J Korean Med Sci 2004;19:155)
Micro images: glial choristoma (figures 3-4)
References: salivary gland choristomas of middle ear (ORL J Otorhinolaryngol Relat Spec 2004;66:141)
Inflammatory/infectious/autoimmune/systemic disorders of ear
Angiolymphoid hyperplasia with eosinophilia of ear
Also called epithelioid (histiocytoid) hemangioma
Rare, benign angiomatous subcutaneous process, usually of auricle and external canal; also elsewhere in head and neck
Usually men and women in 20’s to 40’s, may have history of trauma
Symptoms: pruritis and bleeding after scratching
Case reports: auricular nodule during pregnancy (Archives 2005;129:1168), regression after excision of squamous cell carcinoma on same ear (Dermatol Surg 2004;30:1367), 20 year history of lesions (Dermatol Online J 2002;8:10)
Treatment: local excision or laser desiccation are usually curative
Gross: pink-red-brown cutaneous papules or subcutaneous nodules up to 1 cm; may coalesce to form plaque-like lesions
Gross images: papule on ear
Micro: unencapsulated but circumscribed; dermal, nodular proliferation of granulation type tissue with haphazard, small caliber, irregularly shaped blood vessels with epithelioid endothelial cells containing hyperchromatic nuclei; also patchy lymphocytes, eosinophils and histiocytes
Cytology: no evidence of malignancy; vascular structures, eosinophils, lymphocytes, and clusters of cuboidal cells with vacuoles in abundant acidophilic cytoplasm (Diagn Cytopathol 1998;18:227)
Micro images: various images #1; #2 (site unknown); #3; thick walled vessels lined by prominent epithelioid cells with inflammatory infiltrate
DD: hemangioma (no epithelioid endothelial cells, no inflammatory infiltrate), angiosarcoma (anastomosing vascular channels lined by pleomorphic cells with increased mitotic activity, no inflammatory infiltrate), Kimura’s disease (large, deep, subcutaneous plaques in young Asian men, often regional lymphadenopathy, peripheral blood eosinophilia and elevated serum IgE levels; prominent lymphoid follicles and fibrosis with less prominent capillary proliferation, no aggregates of non-canalized endothelial cells)
References: eMedicine #30
Chondrodermatitis nodularis chronica helicis
Also called Winkler’s disease
Idiopathic, nonneoplastic ulcerative lesion of auricle
Usually men ages 40+; uncommon in women
Symptoms: appears spontaneously; unilateral, painful nodule
Treatment: wedge or cartilage excision, glucocorticoid injection; frequently recurs
Gross: dome shaped nodule, 0.3 to 1.8 cm, with crusty scale covering central area of ulceration
Gross images: nodule on antihelix, nodule on superior helix; various nodules
Micro: central ulceration of epidermis with adjacent acanthosis, hyperkeratosis, parakeratosis and pseudoepitheliomatous hyperplasia; base of ulcer has granulation tissue that usually involves perichondrium and cartilage; usually nerve hyperplasia identified with S100 (J Am Acad Dermatol 2006;55:844); may have foci of fibrinoid necrosis; no dermal adnexa at site of lesion
Micro images: infiltration of papillary dermis by epithelioid (E) cells; various images #1; #2; #3; lesion with zonal pattern
DD: clinically resembles carcinoma; vascular proliferation may resemble a glomus tumor
References: J Clin Path 1959;12:179, eMedicine
Primary gout (90%): idiopathic (85%) due to overproduction of uric acid or known enzyme defects (5%, partial hypoxanthine-guanine phosphoribosyl transferase deficiency [HGPRT]); may have normal excretion
Secondary gout (10%): increased nucleic acid turnover due to leukemia/lymphoma, chronic renal disease, HGPRT deficiency
See also Joints chapter
Xray: no calcifications
Laboratory: elevated urinary uric acid, leukocytosis, increased erythrocyte sedimentation rate
Gouty tophi (depositions of sodium urate) commonly deposit in helix of ear as painful, skin-covered, firm nodules
Gross images: gouty tophi
Micro: tophi are composed of needle-shaped aggregates of urate crystals with surrounding foreign body giant cell reaction; urate crystals dissolve with routine processing, so fix a smear of crystals in absolute alcohol or nonaqueous fixation; no birefringence
Micro images: site unknown - A: Xray; B: Diff-Quick; C: Pap smear; D: polarized light; E: H&E; crystals and giant cells
DD: pseudogout (rhomboid or needle shaped, weak positive birefringence with polarized light, radiographic calcifications)
References: Wikipedia
Also called donovanosis
Rare in children and at this site; may be transmitted during vaginal delivery
Case reports: children 5 and 8 months old with mastoiditis and external ear discharges (AJCP 1997;108:510)
Treatment: antibiotics
Micro images: cytology-site unknown
Idiopathic auricular ossificans
Ectopic calcification of auricle (“rigid ear”) of unknown etiology
Very rare (<20 cases reported)
Case reports: 60 year old man with 10 year history of slowly stiffening auricles (Archives 2004;128:1432)
Micro: cartilaginous replacement by bone
DD: specific causes (frostbite, physical trauma, inflammatory conditions, Addison’s disease)
References: J Am Acad Dermatol 2003;49:142, Laryngoscope 1985;95:566
Idiopathic cystic chondromalacia of auricular cartilage
Also called auricular or endochondral pseudocyst
Benign cystic degeneration of auricular cartilage of unknown cause
Usually men age 20-40 years
Unilateral swelling of cartilage over weeks to years, most commonly on scaphoid fossa of auricle
May be due to minor trauma
Case reports: 32 year old man with auricular swelling (J Clin Path 1994;47:961)
Treatment: excision
Micro: fluid filed distended mass composed of cyst-like wall with fibrous and granulation tissue lining but no epithelium; cyst contains 1-2 mm rim of cartilage; cyst fluid resembles olive oil; no/mild atypia
Micro images: central cystic degeneration of auricular cartilage; factor VIII+ lining of pseudocyst
DD: relapsing polychondritis, subperichondrial hematoma, chondrodermatitis nodularis helicis chronicus
References: Archives 1986;110:740, Eur J Dermatol 2000;10:451, eMedicine
Inflammatory aural / otic polyp
Inflammatory polypoid proliferation of middle ear mucosa secondary to chronic otitis media
May perforate tympanic membrane and appear to originate from external auditory canal; with time, may destroy ossicles
More common in children, but occurs in all ages
Often associated with extensive disease of mastoid air cell system (in rural India, Am J Otolaryngol 2003;24:155) or cholesteatoma of middle ear (Acta Otorrinolaringol Esp 2003;54:161)
Treatment: excision; possibly mastoid exploration
Gross: polypoid, soft/rubbery, pink/tan/red lesion
Gross images: aural polyp
Micro: squamous or ciliated columnar epithelium containing lymphocytes, histiocytes, plasma cells, eosinophils; also Mott cells (plasma cells with large eosinophilic immunoglobulin) and granulation type tissue; usually mast cells (J Laryngol Otol 1995;109:491), variable neutrophils, multinucleated giant cells, cholesterol granulomas and tympanosclerosis
DD: plasmacytoma (monoclonal light chains)
Asians, usually males
Large subcutaneous nodules, usually in head and neck, with regional lymphadenopathy and peripheral eosinophilia
Case reports: with coexisting angiolymphoid hyperplasia with eosinophilia (Int J Dermatol 2006;45:139), with bilateral auricular masses (AJNR Am J Neuroradiol 1999;20:1976)
Micro: prominent lymphoid proliferation, sparse vascular proliferation; often extends to fascia and skeletal muscle; adipose tissue is often fibrotic; eosinophils are common
Micro images - neck mass - nodular, mixed inflammatory infiltrate of reticular dermis; infiltrate is poorly circumscribed and contains several lymphoid follicles; lymphoid hyperplasia; dense inflammatory infiltrate with numerous eosinophils
DD: angiolymphoid hyperplasia with eosinophils (more superficial, may have rare/no eosinophils), angiosarcoma
Inflammation of inner ear secondary to various causes
Rare today due to antibiotics for otitis media, syphilis and other diseases
Serous: mildest form; due to local irritant, such as acute or chronic otitis media without bacterial invasion of inner ear, temporal bone or meningitis; has accumulation of granular eosinophilic material within labyrinth or perilymphatic spaces, with mild endolymphatic hydrops
Suppurative: neutrophils and bacteria are present in perilymphatic spaces; may destroy sensory end organs and membranous labyrinth
Chronic: due to local osteitis of otic capsule secondary to prior acute suppurative labyrinthitis or chronic inflammation of membranous labyrinth
Ossifying: end stage of suppurative labyrinthitis, with ossification of labyrinthian structures but no inflammatory infiltrate
Viral: due to mumps, measles, CMV; viral cytopathic changes are present in scala media
Complications include involvement of intracranial structures (meningitis, venous thrombophlebitis, intracranial abscess, facial nerve paralysis, otic hydrocephalus)
Case reports: CMV endolabyrinthitis in premature male newborn (Archives 1977;101:118), due to acute otitis media (Yonsei Med J 2005;46:161, free full text)
Micro images: purulent labyrinthitis
References: eMedicine #1, #2, Wikipedia
Malakoplakia of ear
Rarely occurs in middle ear
Due to inability of histiocytes to ingest bacteria such as E coli, with accumulation in phagolysosomes
Case reports: 9 month old with involvement of temporal bone (J Laryngol Otol 1991;105:568)
Micro: sheets of histiocytes with eosinophilic, granular to vacuolated cytoplasm (Hansemann cells), lymphocytes, plasma cells, neutrophils; diagnostic feature is intracytoplasmic or extracellular calcospherites (Michaelis-Gutmann bodies)
Micro images: various images-not ear #1; #2
Positive stains: Michaelis-Gutmann bodies are PAS+ diastase resistant, Prussian blue/iron+, von Kassa/calcium+
Also called endolymphatic hydrops
Idiopathic disorder of inner ear associated with episodic attacks of vertigo, fluctuating sensorineural hearing loss, tinnitus and sensation of aural fullness
Incidence varies from 7.5 per 100K in France to 157 per 100K in England
60% women, peaks in 40’s to 60’s, but wide age range
Rarely occurs in children (J Laryngol Otol 2006;120:343)
Associated with HLA B8/DR3
May be due to accumulation of endolymph in membranous labyrinth, perhaps due to inadequate absorption by endolymphatic sac
Treatment: dietary modification, intermittent dehydration, diuretics, vasodilators in increase microcirculation of ear; 60-80% improve; surgery includes shunting and decompression of endolymphatic sac (Laryngoscope 2005;115:1454), labyrinthectomy, sectioning of vestibular nerve
Micro: initially involves cochlear duct and saccule; later entire endolymphatic system with dilation, rupture and collapse of membranous labyrinth with possible fistula; may have severe atrophic changes with loss of cochlear neurons
Micro images: section through cochlea
References: National Institutes of Health, Wikipedia, eMedicine
Iatrogenic due to petrolatum based ointments
Usually nasal cavity and paranasal sinuses; occasionally affects middle ear
History of recent surgery with packing of area (AJCP 1977;67:118)
Associated with postoperative adhesions after sinus surgery (Laryngoscope 2003;113:1123)
Case reports: post-tympanoplasty (Laryngorhinootologie 2004;83:445); involving mastoid and middle ear (Laryngorhinootologie 2004;83:445)
Treatment: symptomatic
Gross: ointment-like material within granulation tissue
Micro: pseudocysts within fibrous tissue with lymphocytes, histiocytes, giant cells and plasma cells; pseudocysts contain “parent bodies” containing numerous spherules
Micro images: Aspergillus (figure 3) and myospherulosis (figure 4) in sinus; brown pseudocysts surrounded by granulation tissue
Cytology images: in paranasal lavage
Negative stains: GMS for fungi
Necrotizing “malignant” external otitis
Potentially fatal external otitis due to Pseudomonas aeruginosa (Ann Otolaryngol Chir Cervicofac 2000;117:291), Aspergillus or other fungal infection
Usually older patients, often with diabetes, chronic debilitation or immunodeficiency; also undernourished African infants (Rev Laryngol Otol Rhinol (Bord) 2002;123:225)
Initially affects external auditory canal with symptoms of acute otitis externa; later pain, purulent otorrhea and swelling; may progress to cellulitis, chondritis, osteomyelitis (Rev Stomatol Chir Maxillofac 2006;107:167), involve middle ear space or base of skull, and cause cranial nerve palsies, meningitis, venous thrombosis or brain abscess
Up to 75% mortality if treatment is delayed
Due to tissue ischemia (from above primary pathologic state) plus neutrophilic migratory defect plus virulence of Pseudomonas
Treatment: antibiotics, surgical debridement, hyperbaric oxygen (HNO 2003;51:315)
Case reports: oxalate crystals within necrotic tissue are associated with Aspergillus niger infection (Mod Path 1993;6:493), due to Klebsiella pneumoniae infection (Eur Arch Otorhinolaryngol 2006;263:344), Stenotrophomonas maltophilia (Hautarzt 2003;54:1080), Staphylococcus epidermidis (Eur Arch Otorhinolaryngol 1999;256:439)
Gross: ulcerated skin near osseous portion of external auditory canal, often with abundant necrotic and granulation tissue
Micro: epithelium is necrotic or ulcerated with pseudoepitheliomatous hyperplasia, marked mixed inflammatory infiltrate in subcutaneous tissue, necrotizing vasculitis; also necrotic bone and cartilage with heavy inflammatory infiltrate in viable bone; variable sequestra of nonviable bone or cartilage
Micro images: gram stain shows P. aeruginosa and coagulase negative Staph
Positive stains: gram stain (gram negative rods)
DD: squamous cell carcinoma
References: American Family Physician
Acute or chronic infectious disease of middle ear
Usually childhood disease caused by Streptococcus pneumoniae or Haemophilus influenzae (Pediatr Infect Dis J 2004;23:1142); also coinfection by viruses (Clin Infect Dis 2006;43:1417)
Rarely caused by fungi or Pneumocystis in HIV+ patients
Hyperemic, opaque and bulging tympanic membrane with limited mobility; may have purulent otorrhea
Infection probably occurs post-pharyngitis via eustachian tube
Severe cases are associated with destruction of ossicles
Tympanosclerosis: dystrophic calcification of tympanic membrane or middle ear associated with recurrent cases of otitis media, occurs in 3-33% of cases; may be reversible in children, usually irreversible in adults and associated with conductive hearing loss
Treatment: antibiotics (Pediatr Infect Dis J 2006;25:1102) or observation (Lancet 2006;368:1429); complications of mastoiditis, labyrinthitis, meningitis or abscess are now rare
Gross: not a common specimen, but may have small fragments of soft/rubbery granulation tissue
Micro: acute and chronic inflammatory cells, haphazard glandular metaplasia (Laryngoscope 1982;92:273) with cilia, fibrosis, hemorrhage, foci of calcification (tympanosclerosis), cholesterol granulomas and reactive bone formation
Cholesterol granulomas: foreign body granulomas in response to cholesterol crystals from rupture of red blood cells and breakdown of lipid bilayer in cell membrane, prominent cholesterol clefts; associated with interference to drainage or ventilation of middle ear space; not related to cholesteatomas
Micro images: serous otitis media
DD: middle ear adenoma (regular, not haphazard glands, no cilia)
References: eMedicine #1, #2
Disorder of bone remodeling affecting bony labyrinth and stapes footplate
Does not appear to occur outside temporal bone (Am J Otol 1999;20:162)
Causes fixation of stapes footplate in oval window and inability to transmit sound waves, manifesting as conductive hearing loss
Usually women; 50% have family history; begins in teenagers and slowly progresses
More common in whites than blacks, Asians or Native Americans
Associated with measles virus (Ann Otol Rhinol Laryngol 2001;110:897)
85% bilateral
Treatment: stapedectomy (correction of fixation of footplate of stapes)
Gross: specimens are usually head and crura of stapes, which are not affected by disease
Micro: initially bone resorption and replacement by cellular fibrovascular tissue around blood vessels; then immature bone is deposited with continuous resorption and remodeling; over time, bone is deposited with increased collagen and reduced ground substance, resulting in densely sclerotic bone with prominent cement lines
Micro images: a. Temporal bone with otosclerosis fixing the stapes; b. Otosclerosis involving the wall of the cochlea; c. Normal Bone
References: Wikipedia, eMedicine
Paget’s disease of bone of temporal bone
Also called osteitis deformans
Chronic progressive disease of increased bone turnover, affects skull and temporal bone in 70% of cases, with hearing loss in half of these cases
Hearing loss is due to compression of cranial nerve VIII and apparently loss of mineral density of cochlear capsule (Laryngoscope 2004;114:598)
Familial cases are due to mutations in bone metabolism pathway genes (Nat Clin Pract Rheumatol 2006;2:270)
Causes enlargement and tortuosity of superficial temporal artery and its anterior branches
Also affects numerous structures of external, middle and inner ear