Adhesive otitis media
Adhesive otitis media is a condition in which the pars tensa of the tympanic membrane becomes severely retracted and adheres to the promontory or ossicles. This adhesion cannot be reversed by Eustachian tube inflation and is accompanied by significant hearing loss. It is generally believed to result from prolonged, untreated, or inadequately treated middle ear inflammation, particularly chronic otitis media with effusion. The adhesion is characterized by a lack of the fibrous layer of the tympanic membrane and normal middle ear mucosa between the thin epithelial layer and the bony promontory.
This condition is closely related to Eustachian tube dysfunction; however, typical cases often present with normal Eustachian tube function. This suggests that once Eustachian tube function is restored, the adhered tympanic membrane neither recovers naturally nor progresses further, resulting in a relatively stable state. At this stage, tympanostomy tube placement is ineffective. Hearing aids can be used to address hearing loss, or tympanoplasty may be performed.
If Eustachian tube dysfunction persists or the isthmus of the tympanic cavity becomes obstructed, leading to negative pressure in the mastoid cavity, the adherent tympanic membrane may worsen, further destroying the ossicles and extending into the epitympanum to form a cholesteatoma.
Atelectatic otitis media is characterized by retraction or collapse of the tympanic membrane, typically resulting from prolonged Eustachian tube dysfunction and chronic otitis media with effusion. In this condition, the tympanic membrane becomes thin and atrophic, losing its tension and support. The effusion in the tympanic cavity becomes less abundant and more viscous, though irreversible adhesion has not yet occurred. Tympanostomy tube placement is effective at this stage, but tympanoplasty should be approached cautiously.
Figure 1 Left atelectatic otitis media
Atelectatic otitis media can be classified into four types:
- Mild retraction of the tympanic membrane
- Retraction of the tympanic membrane with adhesion to the incus
- Retraction of the tympanic membrane with adhesion to the promontory
- Retraction of the tympanic membrane with adhesion to the hypotympanum, accompanied by keratin debris accumulation and cholesteatoma formation
This classification essentially reflects the degree of tympanic membrane adhesion and encompasses a spectrum of diseases associated with Eustachian tube dysfunction. It is difficult to attribute it to a single disease entity. Among these, type 3 corresponds to typical adhesive otitis media, while type 4 represents cholesteatoma of the middle ear.
Cholesterol granuloma of the middle ear
The etiology of cholesterol granuloma remains unclear. Pathologically, it is characterized by the presence of cholesterol crystals and secondary reactive granulation tissue in the middle ear cavity. This condition is more common in adults.
Clinical manifestations
Conductive hearing loss is generally more severe than that seen in otitis media with effusion. Examination may reveal a blue or dark brown tympanic membrane. If the tympanic membrane is perforated due to granulation tissue, brownish discharge may be observed. A detailed history often reveals a long-standing history of otitis media, sometimes dating back to childhood. Cholesterol granuloma can be localized to specific air cells in the mastoid or middle ear or may involve the entire middle ear. Temporal bone CT scans typically show soft tissue densities in the tympanic cavity and mastoid, with occasional bony destruction. Differential diagnosis should include conditions that present with blue tympanic membrane, such as high jugular bulb, middle ear paraganglioma, traumatic hemotympanum, and middle ear hemangioma.
Treatment
Management is challenging. Tympanostomy tube placement alone is often ineffective and may result in excessive secretion. Recurrence after surgery is also possible.
Tympanosclerosis
Tympanosclerosis is a series of pathological changes in the tympanic membrane and middle ear mucosa caused by prolonged chronic inflammation.
Pathology
In the tympanic membrane, the fibrous layer is affected, leading to the formation of white plaques. In the middle ear mucosa, calcium salt and phosphate crystal deposits occur in the submucosa, sometimes accompanied by hyaline degeneration or new bone formation. When calcification involves the ossicles or the surrounding areas of the ossicular chain, conductive hearing loss may occur.
Surgical treatment includes repair of tympanic membrane perforations and removal of sclerotic lesions around the oval window and stapes during surgery. In case of severe stapes fixation, hearing aids may be recommended postoperatively, or a second-stage stapes surgery may be performed.
Latent otitis media
Latent otitis media is a non-suppurative granulomatous middle ear inflammation, possibly a sequela of acute otitis media. It is characterized by the absence of tympanic membrane perforation but the presence of chronic inflammatory granulation tissue in the middle ear cavity or mastoid.