Cholesteatoma of the petrous bone: the crucial role of diffusion-weighted MRI

Modified Translabyrinthine Approach for Massive Petrous Bone Cholesteatoma Removal and Cochlear Preservation Using Latent Spaces Anterior to the Cochlea

OBJECTIVE

Microsurgery is the reference standard treatment of petrous bone cholesteatoma (PBC). In most cases, radical removal of an extensive PBC can only be achieved at the cost of sacrificing the cochlea. Such treatment will result in the impossibility of future cochlear implantation for hearing rehabilitation purposes. To address this issue, a modification of the traditional translabyrinthine (TL) approach with endoscopic assistance has been developed for radical removal of extensive PBC with preservation of the cochlea.

METHODS

From June 2017 to December 2017, 3 patients with a massive PBC underwent surgical removal using the modified TL approach by the senior author in our department. We reviewed the patient characteristics and retrospectively studied the surgical outcomes and postoperative complications. In the present report, we have described our modified TL approach in detail.

RESULTS

Complete resection of the PBC and successful cochlea preservation were achieved in all 3 patients. No recurrence had developed during the follow-up period. However, various degrees of cochlear ossification were observed in 2 patients postoperatively.

CONCLUSIONS

This modified TL approach provides the possibility of fully exposing the whole petrous apex without removing the cochlea in selected cases. However, the development of long-term cochlear ossification requires further investigation to allow for successful cochlear implantation.

Use of non-echo-planar diffusion-weighted MR imaging for the detection of cholesteatomas in high-risk tympanic retraction pockets

BACKGROUND AND PURPOSE

Non-echo-planar DWI MR imaging (including the HASTE sequence) has been shown to be highly sensitive and specific for large cholesteatomas. The purpose of this study was to determine the diagnostic accuracy of HASTE DWI for the detection of incipient cholesteatoma in high-risk retraction pockets.

MATERIALS AND METHODS

This was a prospective study of 16 patients who underwent MR imaging with HASTE DWI before surgery. Surgeons were not informed of the results, and intraoperative findings were compared against the radiologic diagnosis. Sensitivity, specificity, and positive and negative predictive values were calculated.

RESULTS

Among the 16 retraction pockets, 10 cholesteatomas were diagnosed intraoperatively (62.5%). HASTE showed 90% sensitivity, 100% specificity, 100% positive predictive value, and 85.7% negative predictive value in this group of patients. We found only 1 false-negative finding in an infected cholesteatoma.

CONCLUSIONS

We demonstrate a high correlation between HASTE and surgical findings, suggesting that this technique could be useful for the early detection of primary acquired cholesteatomas arising from retraction pockets and could help to avoid unnecessary surgery.

Diagnostic accuracy of non-echo-planar diffusion-weighted MRI versus other MRI sequences in cholesteatoma

INTRODUCTION

Non-echo-planar imaging (EPI) MRI has been recently introduced to improve the detection of small-sized cholesteatoma and decrease different artefacts occurring in the EPI-diffusion-weighted (DW) technique. This technique is also time saving in comparison to delayed post-contrast imaging. We prospectively assessed the diagnostic accuracy of MRI including delayed post-contrast standard MRI, EPI and non-EPI-DW sequences in the detection of middle ear cholesteatoma.

METHODS

We evaluated 35 patients suspected of having cholesteatoma who underwent MRI including delayed post-contrast MRI, EPI and non-EPI-DW sequences prior to their planned surgery, and the MR findings were compared with surgical findings. Two experienced radiologists reported the images. Sensitivity, specificity and predictive values of MRI were estimated.

RESULTS

We detected 26 cases of cholesteatoma at surgery. Sensitivity and specificity of delayed post-contrast MRI, EPI DW and non-EPI DW were 73.1 and 77.8%, 61.5 and 88.9%, and 96.2 and 100%, respectively, as interpreted by the first radiologist. Sensitivity and specificity of delayed post-contrast MRI, EPI-DW sequence and non-EPI-DW sequence were 84.6 and 88.9%, 50 and 88.9%, and 92.3 and 100%, respectively, as interpreted by the second radiologist.

CONCLUSION

The non-EPI MRI technique is a more accurate method in detecting middle ear cholesteatoma in comparison to other conventional sequences.

Cholesterol granuloma of the middle ear invading the cochlea

OBJECTIVES

To report a second case of cholesterol granuloma of the middle ear invading the cochlea.

MATERIAL AND METHODS

A 54-year-old woman, who had undergone right-side tympanoplasty with stapedectomy, complained of intermittent right-side otorrhea associated with cophosis. Otomicroscopy found anterior eardrum perforation with mucopurulent effusion. Computed tomography (CT) showed a lesion filling the tympanic cavity, exposing the tympanic facial nerve, with destruction of the ossicles; the vestibule and cochlea were ossified except for the basal turn. The petrous apex was normal. Magnetic resonance imaging (MRI) showed invasion of the cavity and basal turn of the cochlea by a mass in heterogeneous hypersignal on T-1 weighted images, non-enhanced by gadolinium injection, and hyperintensity on T2-weighted images. Cholesterol granuloma of the middle ear was suspected, with surgery indicated due to the facial nerve exposure and cochlear invasion.

RESULTS

A brownish-yellow compressive mass invading the basal turn of the cochlea, suggestive of cholesterol granuloma, was removed. Histologic examination confirmed diagnosis.

CONCLUSION

Direct invasion of the otic capsule by cholesterol granuloma is extremely unusual. Surgery is indicated in such cases, to avoid onset of neurologic complications.

The role of magnetic resonance imaging in the postoperative management of cholesteatomas

Conventional CT and MRI scans have low specificity when it comes to differentiating granulation tissue from relapsing cholesteatoma.

Aim

this paper aims to analyze the use of DWI and delayed post-contrast T1-weighed imaging in the detection of recurring cholesteatomas.

Materials and method

this is a cross-sectional prospective study that looked at 17 cholesteatoma patients postoperatively. All patients underwent diffusion magnetic resonance imaging at 1.5T, T1, T2, and delayed post-contrast T1 and images were produced from both coronal and axial planes. Two radiologists assessed the images and decided consensually that the presence of hyperintensive signal in DWI on T2, iso/ hypointensive signal on T1, and absence of contrast uptake were indicative of relapsing cholesteatoma. Surgical review findings were compared to DWI scans.

Results

eleven of the twelve cases of recurring cholesteatoma presented hyperintensive signal in the DWI scans. None of the patients with granulation tissue in the surgical wound presented hyperintensive signal in the DWI scans. A patient with an abscess in the internal acoustic meatus also presented a hyperintensive signal in the DWI scans. Sensibility, specificity, positive predictive value and negative predictive value were 91.6%, 60.0%, 84.6%, and 75.0%, respectively.

Conclusion

DWI combined with delayed post-contrast T1 SE sequence proved to be useful in the differential diagnosis of granulation tissue and recurring cholesteatoma.

Benign mass lesions deep inside the temporal bone: imaging diagnosis for proper management

CONCLUSION

Among mass lesions inside the temporal bone, benign tumors and cholesteatomas can be differentiated by contrast enhancement in T1-weighted images (T1WI) and by diffusion-weighted images (DWI). Moreover, DWI will also facilitate discrimination between cholesteatomas accompanied by granulation and other non-neoplastic lesions such as mucoceles and cholesterol granulomas.

OBJECTIVES

To review the imaging characteristics of mass lesions inside the temporal bone and to investigate pertinent imaging modalities for differential diagnosis, which is crucial for appropriate treatment planning.

PATIENTS AND METHODS

This was a retrospective case series study of six patients seen between 2002 and 2005 with mass lesions deep inside the temporal bone.

RESULTS

One patient had facial schwannoma, two had glomus jugulare tumor, and three had cholesteatoma. Plain high resolution CT gave few clues to the nature of the mass lesions. MRI study provided us with better clues: contrast enhancement on T1WI was observed only in benign tumors and only cholesteatomas showed high intensity on DWI. With the assistance of neurosurgeons, surgery was successfully performed in all cases.

Petrous bone cholesteatoma: clinical longitudinal study

The object of this retrospective study was to describe a series of patients with petrous bone cholesteatomas, paying particular attention to classification, diagnosis, surgical strategy, results, complications and recurrences. Furthermore, the study was designed to evaluate the impact of imaging techniques on an early diagnosis. Topographically, the petrous bone cholesteatomas of the present series were grouped using Sanna's classification and different surgical approaches were used. High resolution CT and/or MRI were used to follow-up the patients. The case notes of 52 patients with petrous bone cholesteatomas who were referred to our hospital for surgery between 1987 and 2003 were reviewed postoperatively. There were 45 primary cases and 7 recurrences. The facial nerve had been infiltrated and compressed by the cholesteatoma in 18 patients. Fourteen were managed with cable grafts using sural nerve or great auricular nerves. About 26 patients with preoperative grade I confirmed their normal facial function in 23 cases. In the other ten patients, the preoperative facial paralysis was due to compression by the cholesteatoma and its removal provided partial recovery of facial function in four patients. Our study compared two observation periods (1987-1996 and 1997-2003) when the diffusion and the availability of imaging techniques in our national health system had considerably increased. Two important factors emerged: firstly, the number of less extensive surgical approaches was higher in the more recent observation period, proving that cholesteatomas smaller in size had been diagnosed. Secondly, preoperative facial paralysis was less frequent in the same period-falling to 25% of cases of total facial paralysis from the 45.8% of the earlier period-practically half as much. The partial paralyses instead increased slightly, demonstrating that otologists have become more sensitive to and pay more attention to this symptom.