Association of Hearing Loss and Otologic Outcomes With Fibrous Dysplasia

Abstract

IMPORTANCE Fibrous dysplasia (FD) and McCune-Albright syndrome (MAS) are rare bone and endocrine disorders in which expansile fibro-osseous lesions result in deformity, pain, and functional impairment. The effect of FD on hearing and otologic function has not been established. OBJECTIVES To characterize audiologic and otologic manifestations in a large cohort of individuals with FD/MAS and to investigate potential mechanisms of hearing loss. DESIGN, SETTING, AND PARTICIPANTS In this natural history study, individuals with craniofacial FD seen at a clinical research center underwent clinical, biochemical, computed tomographic, audiologic, and otolaryngologic evaluations. MAIN OUTCOMES AND MEASURES Clinical and radiologic features associated with hearing loss and otologic disease were evaluated. Conductive hearing loss was hypothesized to be associated with narrowing of the external auditory canal (EAC), FD involving the epitympanum, and FD crowding the ossicular chain. Sensorineural hearing loss was hypothesized to be associated with FD affecting the internal auditory canal (IAC) and otic capsule. RESULTS Of the 130 study participants with craniofacial FD who were evaluated, 116 (89.2%) had FD that involved the temporal bone (median age, 19.6 years; range, 4.6-80.3 years; 64 female [55.2%]), whereas 14 (10.8%) had craniofacial FD that did not involve the temporal bone. Of the 183 ears with temporal bone FD, hearing loss was identified in 41 ears (22.4%) and was conductive in 27 (65.9%), sensorineural in 12 (29.3%), and mixed in 2 (4.9%). Hearing loss was mild and nonprogressive in most participants. Whereas EACs were narrower in ears with FD (mean difference [MD], 0.33 mm; 95% CI, 0.11-0.55 mm), this finding was associated with conductive hearing loss in only 4 participants. Fibrous dysplasia crowding of the ossicles was associated with conductive hearing loss (odds ratio [OR], 5.0; 95% CI, 2.1-11.6). The IAC length was not different between ears with and without FD (MD, −0.37; 95% CI, −0.95 to 0.211); however, canals were elongated in ears with sensorineural hearing loss (MD, −1.33; 95% CI, −2.60 to −0.07). Otic capsule involvement was noted in only 4 participants, 2 of whom had sensorineural hearing loss. Both MAS-associated growth hormone excess (OR, 3.1; 95% CI, 1.3-7.5) and neonatal hypercortisolism (OR, 11; 95% CI, 2.5-55) were associated with an increased risk of hearing loss. CONCLUSIONS AND RELEVANCE Hearing loss in craniofacial FD is common and mild to moderate in most individuals. It typically arises from FD crowding of the ossicular chain and elongation of the IAC, whereas EAC stenosis and otic capsule invasion are less common causes. Individuals with craniofacial FD should undergo otolaryngologic evaluation and monitoring, including assessment to identify those with high-risk features.

Fibrous Dysplasia of Bone and McCune–Albright Syndrome: A Bench to Bedside Review

“…In a cohort of 183 temporal bones affected by FD, 22% were found to have hearing loss, usually mild and non-progressive. Hearing loss was conductive in 66%, sensorineural in 29%, and mixed in 5% of cases [46]. Internal auditory canal elongation and FD involvement of the ossicular chain were the most common causes identified, and external auditory canal stenosis and otic capsule invasion occurred less frequently.…”

“…In most patients, growth hormone excess occurs concurrently with hyperprolactinemia. Growth hormone excess is an important contributor to morbidity in patients with craniofacial FD, and is associated with a higher prevalence of macrocephaly, optic neuropathy, and hearing loss [56][57][58].…”

“…Several cancers and pre-cancerous lesions have been associated with MAS. In particular, women with MAS have a 3.4-4.5-fold increased risk of breast cancer with a young age of onset (median age [36][37][38][39][40][41][42][43][44][45][46], suggesting that early breast cancer screening is warranted in this population [62]. Other cancers and premalignant neoplasms have been sporadically reported in association with MAS, often with activating GNAS mutations identified at the focus of the tumor.…”

Role of dental clinical and imaging exam during McCune Albright Syndrome diagnosis process: Case Report

“…Boyce and collaborators (Boyce et al, 2018) conducted a cohort study with patients who had temporal bone FD, showing that they have an increased risk of sensorineural and conductive hearing loss (26). Fibrous Dysplasia can also manifest in the mandibular bone, causing malocclusion and dental crowding (29).…”

Fibrous Dysplasia, Paget's Disease of Bone, and Other Uncommon Sclerotic Bone Lesions of the Craniofacial Bones

“…Mild hearing loss in temporal bone involvement is a less common complication. 9 Vision loss due to orbital involvement is only reported in 5%. 8 Development of aneurysmal bone cysts in FD foci is possible and may contribute to rapid progressive symptoms due to compression on adjacent structures.…”