Ear Tumors: Types, Classification, Symptoms, Diagnosis, Treatment

Ear tumors represent a diverse group of formations that can be both benign and malignant (ear cancer). They are localized in various parts of the ear: outer, middle, or inner. Depending on the origin and nature of the tumor, they can cause various symptoms and require specific approaches to diagnosis and treatment.

Definitions of ear tumors

Earlobe Atheroma

A soft tissue benign formation located within the earlobe, representing a sebaceous gland cyst.

Cutaneous Horn (Fibrokeratoma, Horny Keratoma)

A benign precancerous skin condition of the auricle.

Basal cell carcinoma of the auricle (basalioma)

A malignant skin tumor originating from the non-keratinizing basal layer of the epidermis, and is the most common form of cancer.

Squamous Cell Carcinoma of the Auricle

A malignant skin tumor originating from keratinizing cells, is the second most common type of cancer after basalioma.

Glomus Tumor (Paraganglioma)

A benign tumor of the tympanic cavity, located in the area of the tympanic plexus or the bulb of the internal jugular vein.

Congenital Cholesteatoma

A pathological condition in which a tumor-like formation in the tympanic cavity develops in utero, without preceding inflammation and with an intact tympanic membrane.

Vestibular Schwannoma

A benign tumor developing from the cells of the vestibulocochlear nerve sheath.

Classification

Formations of the outer ear:

• Earlobe atheroma;
• Cutaneous horn of the auricle;
• Basal cell carcinoma of the auricle;
• Squamous cell carcinoma of the auricle.

Formations of the middle ear:

• Glomus tumor (paraganglioma);
• Congenital cholesteatoma.

Formations of the inner ear:

• Vestibular schwannoma.

Etiology

Earlobe atheroma – occurs due to blockage of the sebaceous gland duct. Predisposing factors include narrow excretory ducts, increased secretion (sebum), endocrine system dysfunction, and insufficient hygiene. When infection occurs, the cyst can become suppurated.

Cutaneous horn – the exact causes of this condition are not fully established. It occurs more often in elderly people, frequently at sites of constant friction. Risk factors include prolonged UV exposure, HPV (human papillomavirus) carriage, and presence of horns in close relatives.

Basal cell carcinoma of the auricle – the most common type of malignant neoplasm, occurs due to aggressive UV exposure. Risk factors include light skin tone and prolonged exposure, including work under open sun.

Squamous cell carcinoma – also occurs due to excessive UV exposure. Pathologically altered tissues, such as radiation keratosis, chronic ulcers, or scars, are more likely to undergo malignant transformation.

Glomus tumor (non-chromaffin paraganglioma) – the most common tumor of the middle ear. The causes are still unknown, they occur sporadically, however, in 10% of cases, a genetic determinant has been identified.

Congenital cholesteatoma – the exact cause is not established. There are several theories of its origin, most of them based on disruption of cell migration during embryogenesis before the final formation of the fibrous ring of the tympanic membrane, or through microperforations in a mature tympanic membrane during intrauterine infection, which heal postnatally. According to one theory, squamous cells that produce keratin and serve as a matrix for cholesteatoma are found in the amniotic fluid of the tympanic cavity in newborns.

Vestibular schwannoma (acoustic neuroma) – a slow-growing tumor with a clear capsule, originating from nerve sheath cells (Schwann cells). Incidence and etiology are unknown. The formation is more common in individuals with neurofibromatosis type 2.

Anatomy

Earlobe atheroma – presents as a spherical formation with a capsule within the earlobe of small diameter, the cavity filled with whitish detritus (sebum). When infection occurs, the atheroma becomes suppurated, increases in size several times, the skin over the formation becomes hyperemic, fluctuation may be determined, and tenderness on palpation.

Cutaneous horn – a dense formation protruding above the skin of flesh color with clear boundaries, originating from the epidermis, consisting of keratinized keratinocytes. Ulceration is not characteristic, the cartilaginous tissue of the auricle remains intact. The length (1-2cm) exceeds the size of the base, characterized by slow growth and absence of metastases to regional lymph nodes.

Basal Cell Carcinoma of the Auricle – There are several subtypes of basal cell carcinoma: nodular (a firm papule with rounded edges, raised above the skin surface, potentially with a central ulcer or crust), superficial (an erythematous scale of small diameter with irregular edges and heterogeneous color), ulcerative (a skin defect with undermined irregular edges), pigmented (a raised plaque above the skin surface, dark in color), morpheaform (a flat, waxy, poorly defined plaque with pronounced telangiectasia). Microscopically, it is defined as an area of epithelial cells with large hyperchromic nuclei and scant cytoplasm. It originates from the basal layer of the epidermis.

Squamous Cell Carcinoma – Characterized by the presence of atypical cells with intercellular desmosomes and varying degrees of keratinization, it spreads into surrounding tissues (local invasion). Externally, this type of tumor is very diverse; any pathological formation on the skin with indistinct borders and heterogeneous color, long-lasting and bleeding, should be suspected.

Paraganglioma – A tumor of neuroectodermal origin, developing from parasympathetic ganglia formed during embryogenesis from the neural crest. Women are affected more often, with a ratio of about 4:1-6:1. Microscopically, neuroendocrine cells arranged in clusters are identified, with fibrous septa and supporting cells between them. The formation is highly vascularized, has expansive growth, and as it increases, compresses nearby cranial nerves (facial, glossopharyngeal, vagus, accessory, trigeminal). Otoscopically, it appears as a bright burgundy formation, visible behind the tympanic membrane, in some cases protruding into the external auditory canal as a bleeding polyp, with a primary growth zone on the medial wall of the tympanic cavity in the area of the tympanic plexus or in the bulb of the internal jugular vein. Malignant transformation is extremely rare (5%), with the sign of malignancy being the presence of distant metastases, typically found in the lungs, lymph nodes, liver, spine, ribs, and spleen. Depending on the location, 4 types of paraganglioma are distinguished: Type 1 – tympanic glomus tumor, limited to the tympanic cavity; Type 2 – jugular glomus tumor, not invading the bone, limited to the middle ear cavity and jugular bulb; Type 3 – jugular glomus tumor, invading the mastoid process of the temporal bone; Type 4 – jugular glomus tumor, extending into the cranial cavity.

Congenital Cholesteatoma represents retraction pockets of the tympanic membrane with ingrowth of squamous epithelium into the tympanic cavity, which gradually becomes surrounded by cholesterol masses. As the formation grows, it causes carious destruction of the ossicular chain, leading to conductive hearing loss. On otoscopy, it appears as a pearly formation behind an intact tympanic membrane, more often in the anterior-superior quadrant. A mandatory condition for diagnosing a ‘congenital’ cholesteatoma is the integrity of the tympanic membrane and the absence of data on previous middle ear inflammation and surgical interventions on the ear.

Vestibular Schwannoma – More often grows from the upper part of the vestibular nerve in the lumen of the internal auditory canal. Clinically, lateral and medial forms are distinguished. Medial schwannomas are located in the cerebellopontine angle, lateral ones in the lumen of the internal auditory canal. From the internal auditory canal, they can spread into the cranial cavity to the cerebellopontine angle; both forms, when increasing in size, can compress nearby tissues (cranial nerves, cerebellum, brainstem). Microscopically, there is proliferation of spindle-shaped Schwann cells with indistinct contours, the presence of Verocay bodies (cell-free substance surrounded by spindle-shaped nuclei). It has slow expansive growth but can reach large sizes (>2.5 cm), does not metastasize.

Clinical Manifestations

Earlobe Atheroma – In addition to cosmetic discomfort, when suppuration occurs, there is pronounced pain.

Cutaneous Horn is characterized by an aesthetic defect, as the formation protrudes strongly above the body surface, and frequent traumatization is possible. Cases of cutaneous horns ranging from 6 to 10 cm in size have been described in the literature.

Basal Cell Carcinoma of the Auricle – A slowly enlarging, semi-transparent skin formation of heterogeneous color with areas of ulceration, which rarely metastasizes. It has pronounced invasive growth, leading to significant cosmetic defects. There is a high risk of recurrence.

Squamous Cell Carcinoma of the Auricle appears as an erythematous scaly plaque raised above the skin surface, with a high frequency of ulceration; the formation may itch and bleed. This tumor has rapid growth and a high rate of metastasis, and is the cause of death in most cases. In recent years, there has been an increase in incidence. The formation is most common in men, with a ratio of 3:1. Patients with immunodeficiency, including those after organ and tissue transplantation receiving immunosuppressive therapy, have a worse prognosis. Formations with a diameter greater than 2 cm, a penetration depth of more than 2 mm, and localized on the scalp, ears, or nose have a high risk of recurrence.

For paraganglioma of the tympanic plexus, characteristic symptoms include hearing loss (initially conductive, later combined with sensorineural component), pulsatile tinnitus on the affected side, and in cases of glomus tumor localization in the jugular bulb area, cranial nerve paralysis (glossopharyngeal, vagus, and accessory, less commonly hypoglossal) due to jugular foramen blockage. As the tumor spreads into the cranial cavity, symptoms of brain or cerebellum damage and facial nerve paresis may appear.

Congenital cholesteatoma is characterized by a long asymptomatic course. Patients typically seek medical attention when hearing loss, vestibulopathy, facial nerve paresis, or intracranial complications develop.

In vestibular schwannoma, various symptoms (general and local) are observed depending on the tumor’s location. Often, the tumor is asymptomatic. Local symptoms include compression of the vestibulocochlear nerve and associated unilateral sensorineural hearing loss (absence of loudness recruitment phenomenon, absence of acoustic reflex of the stapedius muscle), tinnitus in the affected ear, and vestibular manifestations (spontaneous nystagmus towards the healthy ear, dizziness). Cerebellar compression results in dysdiadochokinesis and ataxia. Large tumors may cause increased intracranial pressure and projectile vomiting. Paresis of facial, trigeminal, and abducens nerves may also occur.

Diagnosis

Earlobe atheroma is assessed clinically, but due to its similarity to other subcutaneous formations (fibroma, lipoma), the final diagnosis is established after pathomorphological results.

Cutaneous horn is diagnosed through examination and medical history.

To confirm carcinoma, a targeted biopsy with subsequent pathohistology is performed.

For the diagnosis of paraganglioma and cholesteatoma, otoscopy is performed first. Then, to determine the exact location of paraganglioma and its vascular origin, high-resolution CT and gadolinium-enhanced MRI are performed. For cholesteatoma visualization, MRI in DWI mode (diffusion-weighted imaging) is used. Before surgical intervention for paraganglioma, angiography and embolization of tumor-feeding vessels are performed.

Healthy relatives in families with a history of paraganglioma undergo genetic testing, allowing for early detection.

When vestibular schwannoma is suspected, comprehensive audiological testing (pure tone and speech audiometry, ABR testing), nystagmus examination, and vestibular tests are conducted. Gadolinium-enhanced MRI is also performed to determine tumor location.

Find more science-based content on our social media channels

Subscribe and don’t miss out on the latest resources

Treatment

Atheromas are surgically removed, with careful excision of the capsule to prevent recurrence. If the formation becomes infected, it is incised, the contents evacuated, a drain is placed, and an aseptic dressing is applied, with regular dressing changes until complete healing.

Precancerous conditions (cutaneous horn) and carcinomas are surgically removed within healthy tissue margins. Radiation therapy is used when there are contraindications to surgery.

Congenital cholesteatoma is surgically removed, with tympanoplasty performed if necessary.

Treatment of paraganglioma and schwannoma involves total surgical removal of the tumor. If complete removal is impossible, partial resection with radiotherapy (gamma knife) is performed. For patients with contraindications to surgery or elderly patients, radiation therapy alone is used. For small schwannomas (~1cm) without significant clinical manifestations, a wait-and-see approach is applied.

All removed tissues must undergo pathomorphological examination.