Non-Neoplastic Diseases of the Ear

Clinical

• Appear at birth

• Unilateral or bilateral, solitary or multiple, sessile or pedunculated, soft or cartilaginous, skin-covered nodules or papules.

• Located on the skin surface often anterior to the auricle and may clinically be mistaken for a papilloma

• Thought to be related to second branchial arch anomalies

• May occur independent of other congenital anomalies but may occur in association with cleft palate or lip, mandibular hypoplasia, or in association with other anomalies such as Goldenhar syndrome (oculoauriculovertebral dysplasia)

Pathology

• Histologically, accessory tragi recapitulate the normal external auricle and include skin, cutaneous adnexal structures, and a central core of cartilage.

Differential Diagnosis

• Squamous papilloma:

  • The absence of cutaneous adnexal structures and cartilage differentiates squamous papilloma from accessory tragi.

Treatment and Prognosis

• Simple surgical excision is curative.

Middle Ear Salivary Gland Heterotopia ( Fig. 23-3 )

• May present with unilateral conductive hearing loss, tend to occur more often in women and occurs over a wide age range

• Often arise in conjunction with facial nerve and ossicular chain anomalies:

  • The combination of facial nerve and ossicular chain anomalies may be explained on the basis of a second branchial arch developmental abnormality.

• Salivary choristomas of the middle ear may be associated with branchial arch abnormalities, most commonly the second arch, as well as abnormalities of the facial nerve, including:

  • Bilateral preauricular pits, conchal bands, an ipsilateral facial palsy, and bilateral Mondini-type deformities

Middle Ear Neuroglial Heterotopia

• True neuronal heterotopias in which isolated neuroglial tissue is located in the middle ear and temporal bone without continuity with the central nervous system is rare.

• More common occurrence in which glial-type tissue is present within the middle ear/temporal bone is seen in association with an acquired encephalocele.

Acquired Encephalocele ( Fig. 23-4 )

• Represent herniation of the brain into the middle ear and mastoid via compromise of the tegmen, a thin bony shell that separates the middle ear and mastoid cavity from the temporal lobe:

  • Tegmen may be compromised or destroyed secondary to trauma or prior surgery, by a complication of otitis media, or due to a congenital defect.

  • Fracture of the temporal bone may also result in herniation of the brain into the middle ear and mastoid.

  • Some cases appear to have occurred spontaneously without known association with an underlying cause and/or without a history of trauma, tumor, cholesteatoma, or surgery of the mastoid or cranium.

• No gender predilection; may occur over a wide age range but tends to occur in older individuals

• Often represent an incidental finding in patients requiring surgery for chronic otitis media

• Associated symptoms may include unilateral conductive hearing loss, persistent otorrhea, leakage of CNS tissue, and/or recurrent episodes of meningitis.

• In patients suspected of having ectopic neuroglial tissue in this site, radiologic imaging (e.g., CT scans) may prove valuable in identifying a defect and/or connection to the CNS.

Clinical

• Equal gender predilection; can occur at any age but is most common in young adults under 30 years of age

• Common in dark-skinned people, especially in young black women who have had their ears pierced

• Most common sites include presternum, limbs, neck, and face; the latter include the earlobes and pinna.

• Most often are asymptomatic but may be associated with pruritus, paresthesia, and pain

• Often associated with a variety of cutaneous injuries, including surgery, ear piercing, BCG vaccinations, injections, burns, lacerations, insect bites; the development following injury may occur anywhere from weeks up to a year.

Pathology

Differential Diagnosis

• Hypertrophic scar:

  • Lack the dense hyalinized collagenous fibers, have more delicate fibrillar collagen, and have a more orderly arrangement of the collagen and fibroblastic cells often with a parallel orientation to the skin surface

  • Mature hypertrophic scars generally do not have an abundance of mucosubstances and therefore have a more compact microscopic appearance.

  • Hypertrophic scars usually do not recur following excision.

• Dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP):

  • Extremely low cellularity of keloids distinguishes it from DF and DFSP.

  • In contrast to keloids there is hyperplasia of the overlying epidermis in DF and DFSP.

  • Unusual variant of dermatofibroma characterized by keloidal-type changes and termed keloidal dermatofibroma has been described:

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      Clinically appear similar to usual DF

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      Characterized by keloidal-like collagen ad­­mixed with elements typically present in DF

  • DFSP shows immunoreactivity for CD34.

Treatment and Prognosis

• Surgical excision is the preferred treatment.

• Recurrence rates of 40% following simple surgical resection have been reported.

• Intralesional steroid (triamcinolone) injections alone provide response rates of 50% to 100% with recurrence rates of 5% to 50% at 5 years:

  • Intralesional triamcinolone injections considered gold standard in nonsurgical management

  • Intralesional verapamil, independent of or in conjunction with triamcinolone, has shown efficacy in treatment of keloids (and hypertrophic scars) with flattening of the raised scars and regaining normal pigmentation.

• When surgery is followed by steroid injection or radiation therapy (10 Gy), recurrence rates are consistently below 50%.

• Intralesional injection of interferon or bleomycin has shown 50% reduction in size, and response appears to be limited to the area treated.

• Intralesional cryosurgery has emerged as a safe and effective new treatment by destroying the hypertrophic scar tissue with minimal damage to the skin surface.

• TGF-β (transforming growth factor beta) and PDGF (platelet-derived growth factor) play an integral role in the formation of keloids, and future development of selective inhibitors of TGF-β might produce new therapeutic tools with enhanced efficacy and specificity for treatment of keloids.

Clinical

• Typically affects men and rarely seen in women; generally affects young and middle-aged adults

• Can occur along any portion of the auricle with the most common site adjacent to the helix

• Symptoms include unilateral, painless swelling of the auricular cartilage without overlying ulceration or erythema; symptoms develop over a period of weeks to years; may occur anywhere on the auricle but the scaphoid fossa (80%) is the most common site; occasionally lesions may be bilateral.

• Markedly elevated lactate dehydrogenase (LDH) levels may be found in aspirated fluid.

• Although trauma has been implicated in causing these lesions, there is no definitive connection to a prior traumatic event and the cause(s) for this condition remains unknown:

  • Belief that repeated trauma stimulated by such phenomena as sleeping on hard pillows, the wearing of motorcycle helmets, stereo headphones, or the Italian birthday custom of having one's auricle pulled

  • Ischemic necrosis of the cartilage or the abnormal release of lysosomal enzymes by chondrocytes may also be cofactors.

• May arise within a potential plane left during embryonic fusion of the auricular hillocks

Pathology

Differential Diagnosis

• Relapsing polychondritis

• Subperichondrial hematoma

• Chondrodermatitis nodularis chronicus helices

Treatment and Prognosis

• Complete surgical excision without distortion of the underlying cartilaginous plate is the preferred treatment and is curative.

• Due to the potential for surgical-related deformity, full-thickness resection is not advocated.

• In addition to the obvious cosmetic concerns, long-standing lesions may result in deformity of the ear.

• Steroid injection alone has been unsuccessful and may result in cartilage deformity.

• Incision and drainage or curettage have shown variable success; needle aspiration alone results in rapid reaccumulation of fluid but, when combined with bolster suture compression, long-term follow-up has shown an absence of recurrences.

Clinical

• More common in men in late middle age and older age groups; considered uncommon in women

• Most frequently occurs along the superior portion of the helix; lateral helical, antihelical, and antitragal involvement also seen

• Spontaneously occurring unilateral painful nodule is the most common clinical presentation; manipulation of the lesion results in intense pain; pain is thought to result from the perichondrial involvement.

• Clinically, the lesions appear as round, reddish areas usually measuring less than 1 cm in diameter; many cases are clinically considered to be carcinomas.

• Cause remains unknown; however, several theories have been suggested, including:

  • Cold exposure

  • Actinic damage

  • Local trauma

  • Degenerative change with pressure necrosis

  • The skin of the auricle is thin with little subcutaneous fat and therefore may be unusually sensitive to injury; further, the vascular supply to the area is somewhat deficient with the avascular cartilage depending on the dermal circulation for its sustenance; these anatomic features may predispose the auricle to the development of CNCH.

• Winkler considered the underlying pathologic event to be a cartilaginous-based process; however, the cause appears to be linked to a primary cutaneous alteration because the cutaneous changes are more significant and a more constant feature.

• Likely that the development of CNCH is multifactorial and includes actinic damage

Pathology

Differential Diagnosis

• Basal cell carcinoma

• Squamous cell carcinoma

  • CNCH is frequently misdiagnosed as a cutaneous malignancy, particularly as basal cell carcinoma or squamous cell carcinoma.

  • Same mistake may be perpetuated by microscopic examination, particularly if the epidermal hyperplastic changes are misinterpreted as representing either squamous cell carcinoma or a hypertrophic actinic keratosis; careful attention to the extensive dermal changes and usually some degree of cartilaginous alterations, along with the well-demarcated nature of the epidermal proliferation and lack of cytologic atypia in the adjacent epidermis, should help in excluding a squamous neoplasm in cases of CNCH.

Treatment and Prognosis

• Complete surgical excision is the preferred treatment and is curative:

  • Surgery includes wedge excision or cartilage excision alone.

• In a minority of patient trials with injection of glucocorticoids directly into the lesion have been shown to be effective in eradicating the lesion.

• No malignant potential

Clinical

• Broad-based outgrowths of bone arising from the wall of the external auditory canal

• Usually are multiple and bilateral

• Tend to remain asymptomatic until they reach a size sufficient to interfere with the normal egress of cerumen and exfoliated skin:

  • Obstruction of the external auditory canal may cause recurrent episodes of external otitis, conductive hearing loss, and tinnitus.

• Predilect to cold water swimmers and surfers, with the highest incidence being found in Australia and New Zealand:

  • White water kayakers are the first inland population to experience exostoses at the rates seen in coastal populations (e.g., surfers); earplugs may be protective.

Pathology

Differential Diagnosis

• Osteoma:

  • Much less common lesion in relationship to the external auditory canal

  • Distinction between exostosis and osteoma is usually readily made on the basis of the clinical presentation; there has been some controversy regarding the ability to distinguish between the two lesions histologically; some authorities consider the lesions histologically different, whereas others do not find the microscopic features sufficiently distinctive to be separated.

Treatment and Prognosis

• Medical treatment resolves the symptomatic external otitis and related hearing loss.

• For patients who do not respond to medical treatment, transmeatal surgical excision is the preferred treatment.

Clinical

• Predilects to women and generally occurs in adults

• May present with preauricular swelling and limited motion of the joint with deviation of the mandible

• May involve the external auditory canal, resulting in an asymptomatic mass lesion

• Radiographic features include the presence of numerous radiopaque loose bodies within the region of the joint but destruction of bone is absent:

  • CT scan excellent to define bony surfaces of the articular joints but fails in detection of loose bodies when these are not yet calcified

  • MRI is gold standard when diagnosis is suspected because it can visualize loose bodies at early stage and also evaluate disk condition and eventual extra-articular tissue involvement

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      On T2-weighted imaging:

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        Signs of low signal nodules within amorphous iso-intensity signal tissues; signs of low and intermediate signal nodules within joint fluids used to detect loose cartilaginous nodules

• Intraoperatively, the lesion is usually confined to the joint space itself and is easily enucleated; on occasion the lesion may extend beyond the joint capsule into the parotid gland, auditory canal, temporal bone, or cranium.

• Rarely occurs in association with pseudogout (calcium pyrophosphate dihydrate deposition disease); see later.

• Pathogenesis:

  • Synovial chondromatosis is a condition in which foci of cartilage develop in the synovial membrane of a joint apparently through metaplasia of the sublining connective tissue of the synovial membrane.

  • Fibroblast growth factor 2 (FGF-2) found to be expressed in chondrocytes and fibroblast-like cells of loose bodies and believed to be involved in the pathogenesis

  • Clonal chromosomal alterations (chromosome 6 abnormalities) in synovial chondromatosis suggest this is a neoplastic lesion rather than a metaplastic/reactive process.

  • Cell proliferation studies have shown intermediate proliferative activity of the cellular com­position of synovial chondromatosis between enchondromas and chondrosarcomas.