|Year : 2016 | Volume
| Issue : 2 | Page : 53-55
Hearing outcome following canaloplasty in fibrous dysplasia
Rohit Ravi1, Balakrishnan Ramaswamy2, Ajay M Bhandarkar2, Krishna Yerraguntla1
1 Department of Speech and Hearing, School of Allied Health Sciences, Manipal University, Manipal, Karnataka, India
2 Department of ENT, Kasturba Medical Hospital, Manipal University, Manipal, Karnataka, India
|Date of Web Publication||27-Jun-2017|
Department of Speech and Hearing, School of Allied Health Sciences, Manipal University, Manipal - 576 104, Karnataka
Source of Support: None, Conflict of Interest: None
Fibrous dysplasia (FD) is a rare condition and is benign in nature. There is narrowing of external auditory canal leading to conductive hearing loss. We present a case of a 23-year-old male with a diagnosis of FD with the complaint of blocking sensation and reduced hearing in the left ear for 2 months. Canaloplasty was carried out by Wilde's postauricular incision following which there was a significant improvement in hearing threshold. This case report highlights the importance of diagnostic tests such as audiometry, tympanometry, high-resolution computed tomography, and histopathological examination. It also highlights the importance of hearing outcomes postsurgical intervention.
Keywords: Canaloplasty, fibrous dysplasia, hearing loss
|How to cite this article:|
Ravi R, Ramaswamy B, Bhandarkar AM, Yerraguntla K. Hearing outcome following canaloplasty in fibrous dysplasia. J Indian Speech Language Hearing Assoc 2016;30:53-5
|How to cite this URL:|
Ravi R, Ramaswamy B, Bhandarkar AM, Yerraguntla K. Hearing outcome following canaloplasty in fibrous dysplasia. J Indian Speech Language Hearing Assoc [serial online] 2016 [cited 2017 Dec 16];30:53-5. Available from: http://www.jisha.org/text.asp?2016/30/2/53/208989
| Introduction|| |
Fibrous dysplasia (FD) is an uncommon, slowly progressive, histopathologically benign fibro-osseous disease. It is characterized by bone marrow being displaced by proliferating fibro-osseous tissue. FD has three variations.,,,
- Monostotic syndrome being the most common (70%) and least severe, seen in patients aged between 10 and 30 years
- Polystotic syndrome where several bones are involved usually on one side of the body, seen in 30%–50% of cases
- McCune–Albright syndrome being the most severe form has a classical presentation of polystotic FD, skin pigmentations, and endocrine abnormalities. It is more common in females, especially precocious puberty.
The involvement of temporal bone (TB) in cases of FD is rare, these patients present with conductive hearing loss, external auditory canal (EAC) stenosis, and mass in TB.,, Saha et al. have discussed the uniqueness of treatment of FD and emphasized on the importance of individualized treatment protocol in such cases depending on symptoms and extent of disease.
In this case report, we highlight a case of FD with TB involvement and discuss the associated audiological findings and standard audiological test to monitor improved hearing results following canaloplasty.
| Case Report|| |
A 23-year-old male visited our tertiary hospital with a history of blocked sensation and reduced hearing in the left ear of 2 months' duration. The patient also reported difficulty in localizing sound. There was no reported history of pain, ear discharge, headache, fever, and trauma.
The otoscopy of the right ear was normal. Otoscopy of the left ear revealed a hard swelling at the bony-cartilaginous junction with overhanging anterior canal wall obscuring the view of the tympanic membrane.
Pure tone audiometry using GSI-61 clinical audiometer revealed normal hearing in the right ear and moderate conductive hearing loss in the left ear [Figure 1]a. The speech audiometry results were in tune with pure tone audiometry results. The tympanometric findings of the left ear revealed “B-” type tympanogram with significantly reduced ear-canal volume (0.3 cc) with absence of ipsilateral reflexes suggestive of middle ear pathology. The right ear testing revealed “A-” type tympanogram with presence of ipsilateral reflexes suggestive of normal middle ear status. TB high-resolution computed tomography (HRCT) scan [Figure 2]a and [Figure 1]b revealed expansive lesion involving the mastoid, temporal, squamous, petrous, and zygomatic portions of the left TB which had a ground-glass appearance along with stenosis of bony part of the left EAC and narrowing of canal for tensor tympani. Histopathological examination revealed narrow and mis-shaped bony trabeculae with interspersed fibrous tissue in lower magnification [Figure 3]a and narrow and curved bony trabeculae surrounded by cellular fibrous stroma in higher magnification [Figure 3]b suggestive of FD.
|Figure 1: (a) Pure tone audiometry (left ear) before surgery. (b) Pure tone audiometry (left ear) after surgery|
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|Figure 2: (a) High-resolution computed tomography temporal bone axial. (b) High-resolution computed tomography temporal bone coronal|
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Canaloplasty of the left ear canal was carried out to restore the hearing of the patient. Consent was obtained regarding the possibility of recurrence of the condition as surgical therapy is not the line of treatment and it was carried out purely to restore the hearing and not as a therapeutic measure for FD. Wilde's postauricular incision 5 mm posterior to the retro-auricular artery was made. The incision was deepened beyond the postauricular muscle. The periosteum over the mastoid was exposed and incised, and the periosteum along with skin of posterior wall of the EAC elevated and reflected anteriorly after incising the skin of the posterior wall of the EAC at bony-cartilaginous junction. Bony outgrowth was identified, and canal wall skin elevated over the bony outgrowth over the anterior, superior, and inferior surfaces. External ear canal wall skin was preserved. The bony outgrowth was gradually curetted until the level of the tympanic membrane and sent for histopathological evaluation. Canal wall was repositioned, and EAC was filled with the Gelfoam till bony-cartilaginous junction and antibiotic-soaked Gelfoam was placed in the EAC, and the incision was closed.
Pure tone audiometry was repeated 6 months postoperatively. Normal hearing was restored in the left ear with mild high frequency loss at 4 and 8 kHz [Figure 1]b.
| Discussion|| |
FD is characterized by slow progressive replacement of bone by proliferating fibrous tissue intertwined by normal or immature bone trabecular arrangement. The exact cause of FD is still unknown. Narrowing of EAC leading to conductive hearing loss is noted along with other symptoms such as otorrhea, retroauricular bulge, tinnitus, and otalgia in FD., Progressive conductive hearing loss caused by occlusion of the EAC or Eustachian tube is the most common cause of TBFD.
Ground-glass appearance on the HRCT and low-to-moderate level of cellular fibrous stroma that surround irregular curvilinear trabeculae of woven bone arranged in Chinese alphabet pattern in histopathologic findings are the diagnostic characteristics of FD. These findings are consistently observed in our case as well.
A systematic review conducted to suggest the best treatment option for FD revealed canaloplasty to have brought improvement in 84% of patients while hearing thresholds remained stable in 18% of patients. Studies further support that normal hearing thresholds can be achieved in case of FD when there is involvement of the external ear canal., In the present study, canaloplasty enabled complete restoration of normal hearing in the affected ear.
| Conclusion|| |
In summary, periodic clinical assessment in such cases will enable to assess the progression of the disease and ensure appropriate palliative intervention. The present case report therefore aims to highlight the importance of appropriate palliative intervention and repeated follow-up testing that has ensured better hearing outcomes.
We would like to thank Dr. Gauri Salgaonkar, assistant professor, Department of Pathology, Kasturba Medical Hospital, Manipal, for valuable contributions in providing the histology slides.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]