Clinical Diagnoses Associated With Histologic Findings of Fibrotic Tissue and New Bone in the Inner Ear

Abstract

Fibrotic tissue or new bone occurs following inner ear inflammation, fracture, or surgery. The prevalence is unknown and was investigated using the National Temporal Bone, Hearing and Balance Pathology Resource Registry database. A search yielded 264 temporal bones with diagnoses of otosclerosis, tumor, Meniere's disease, meningitis, labyrinthitis, chronic otitis media, autoimmune disease, temporal bone fracture, or sensorineural hearing loss. All autoimmune cases contained some new bone, whereas only 20% to 30% of the labyrinthitis/meningitis cases were reported to contain new bone. Otosclerosis, Meniere's disease, and otitis media had relatively few cases containing new bone. Although new bone may derive from surgical trauma, it is also likely to be a result of the disease process. It seems that all these disease processes may contain a common feature that acts as a stimulus to induce fibrosis or bone growth in the inner ear.

Deterioration of hearing in a cochlear implantee with relapsing polychondritis

“…Cochlear fibrosis and new bone formation are common findings in several autoimmune diseases characterized by systemic vascular mechanisms such as lupus, Wegener's ulcerative colitis and polyarthritis nodosa [8], Cogan's syndrome [4], and RP [8,9]. It has been speculated that the underlying mechanism for cochlear ossification is linked to the breakdown of the regulatory processes that normally inhibit mineralization of the extracellular matrix.…”

Cochlear Implantation Outcomes in Patients With Autoimmune and Immune-Mediated Inner Ear Disease

“…The pathogenesis of immune-mediated cochleolabyrinthitis results in a significant inflammatory reaction that triggers a cascade of events culminating with fibrosis and cochlear ossification (5). Some authors have reported the presence of ossification and fibrosis of the cochlear duct in patients with immune-mediated labyrinthitis that seems to mimic the findings noted in ears with meningitisrelated ossification (9).…”

“…Animal models of AIED show that inflammatory infiltrates within the cochlea ultimately can lead to cochlear fibrosis and calcification (4). Postmortem analysis of temporal bones of patients affected with AIED reveals the presence of fibrosis and new bone formation (5). Such fibrosis can potentially lead to osteoneogenesis similar to that which has been observed in postmeningitic deafness and other inflammatory ear conditions (6Y9).…”

Autoimmune inner ear disease

“…Keithley and Linthicum [21] found new bone growth or ossification of the labyrinths of all temporal bones studied from patients with suspected AIED. They suggest that the new bone growth is stimulated by the inflammatory disease process and may be responsible for the profound hearing loss in these patients.…”