Imaging for evaluation of cholesteatoma: current concepts and future directions

Diagnostic Accuracy of Plain Computed Tomography Temporal Bone in Detection of Pre-operative Ossicular Status versus Per-operative Findings in Chronic Otitis Media

Ossicular destruction is a common phenomenon in chronic otitis media due to an imbalance between osteoblasts and osteoclasts. Computed tomography helps us in the assessment of ossicular status, extent of pneumatization, and early identification of complications. This study aims to check the diagnostic accuracy of computed tomography temporal bone for the detection of ossicular erosion in comparison with the surgical findings taken as a gold standard. The use of this investigation as an adjunct can prove to be helpful in planning mastoid exploration as well as a primary reconstruction surgery especially in mucosal and early squamosal diseases. It's a cross-sectional validation study done on 50 patients with chronic otitis media (both mucosal and squamous type) from July 2022 to November 2023. Patients underwent CT scanning of temporal bone and ossicular status was reported by the radiologist. Later on, mastoid surgery was carried out and per operative findings were documented. 2 × 2 tables were formed and diagnostic accuracy of CT temporal bone was checked in terms of sensitivity, specificity, negative predictive value, and positive predictive value. The results revealed that CT temporal bone has a high diagnostic accuracy with a sensitivity of 92.5% and specificity of 100% for malleus (p value < 0.001). For incus and stapes, sensitivity came out to be 93.5% and 76% respectively and specificity values were 94.7% and 100% (p value < 0.001 for all) giving a verdict that the pre-operative use of this radiological investigation should be encouraged by otologists.

Characteristics of repeated recidivism in surgical cases of cholesteatoma requiring canal wall reconstruction

OBJECTIVE

Few reports discuss the characteristics of repeated recidivism of cholesteatoma. We describe the clinical characteristics of patients with cholesteatoma who experienced at least two recidivism episodes after initial surgery for cholesteatoma requiring canal wall reconstruction.

METHODS

We reviewed the medical records of 11 patients who underwent surgery for cholesteatoma with canal wall reconstruction at our department between April 2008 and March 2018 and subsequently experienced two relapses that necessitated revision surgery involving tympanomastoidectomy with canal reconstruction. Patient age at the time of the first surgery ranged from 6 to 56 (mean, 25.7) years. Seven (63.6%) of the 11 patients were male. These 11 patients were classified according to the type of recidivism, and their characteristics (pathology, operation date, operation method, pattern of relapse, and position of recurrence) were investigated.

RESULTS

Four cases involved secondary residual cholesteatoma, with the mean interval between the first revision surgery and the second revision surgery being 23.8 (range, 11-39) months. Secondary residual sites included the anterior tympanic cavity, tympanic sinus, and anterior end of the reconstructed cartilage of the canal wall. The other seven cases involved secondary recurrence, with the mean interval between the first and the second revision surgery being 26.1 (range, 12-57) months. The sites of recurrence were at the edges of the reconstructed cartilage. One notable case involved the cartilage junction, leading us to hypothesize that retraction of the temporal muscle flap and the patulous Eustachian tube was the underlying cause.

CONCLUSION

For residual cholesteatoma, strict measures are necessary to maintain the operation under clear view, and more careful follow-up is necessary in patients who have had previous surgery at another hospital. For recurrent cholesteatoma, it was recognized that Eustachian tube function must be ascertained in advance, and careful observation of the reconstructed cartilage edge is necessary.

A Case of Giant Petrous Apex Cholesteatoma With Pseudomonas Aeruginosa Infection

Petrous apex cholesteatoma is a relatively rare and chronic aggressive disease that occurs in the petrous part of the temporal bone and can be classified as congenital or acquired. Due to the tendency of petrous cholesteatomas to cause bone destruction and invade important structures such as the facial nerve, cochlea, and semicircular canal, patients present mainly with severe hearing loss, progressive peripheral facial palsy, vertigo, etc. When the lesion invades the intracranial region or is infected, intracranial symptoms such as meningitis, lateral sinus thrombosis, and brain abscess may be present. We report a case of giant petrous cholesteatoma with Pseudomonas aeruginosa infection, with the aim of exploring the corresponding clinical treatment and surgical modalities to provide a reference for the clinical management of this type of disease.

Cartilage grafts mimicking cholesteatoma recurrence on diffusion-weighted magnetic resonance imaging: a case series

BACKGROUND

Cholesteatomas present a high risk for residual and recurrent disease, and the surveillance of post-operative patients can be challenging. Diffusion-weighted magnetic resonance imaging is becoming the preferred method for investigating recidivism; however, false positive imaging findings increase the risk of patients undergoing unnecessary second look surgery.

CASE REPORTS

This study reports two patients with false positive diffusion restriction associated with cartilage grafts that mimicked cholesteatoma and resulted in second look surgery with no disease found at operation. This study also discusses the related medical literature, including potential causes of abnormal diffusion restriction and methods to negate this.

CONCLUSION

Caution should be exercised when considering second look surgery in the presence of a cartilage graft and a high confidence of disease clearance. A multi-disciplinary approach is recommended for the operating surgeon to review the images with a radiologist.

High-Resolution Computed Tomography and Intraoperative Correlation in Cholesteatoma: Enhancing Preoperative Evaluation and Surgical Management

INTRODUCTION

Cholesteatoma, a hazardous non-neoplastic lesion of the temporal bone, is prevalent in socio-economically disadvantaged groups in developing nations like India. Timely detection and surgical intervention are essential for effective management. High-resolution computed tomography (HRCT) has revolutionized the assessment of temporal bone pathology, though its role in preoperative evaluation remains debated. This study aimed to validate HRCT's utility in diagnosing cholesteatoma, compare its findings with intraoperative observations, and assess sensitivity and specificity.

METHODS

This diagnostic accuracy study was conducted at a tertiary care center in Western India, from March 2021 to November 2022. HRCT findings of 54 cholesteatoma patients were evaluated and compared with intraoperative findings. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and Cohen's kappa coefficient were calculated.

RESULTS

HRCT demonstrated a sensitivity exceeding 90% in identifying scutum erosion, mastoid sclerosis, and abnormalities in the tympanic membrane, along with a specificity surpassing 90% in detecting various conditions, including facial canal erosion, sinus plate erosion, lateral semicircular canal erosion, erosion of the posterior wall of the external auditory canal, and abnormalities in the tympanic membrane. Furthermore, HRCT exhibited an accuracy of over 90% in detecting most pathologies. There was a perfect or near-perfect agreement observed for abnormal tympanic membrane, sinus plate erosion, mastoid sclerosis, and erosion of the posterior wall of the external auditory canal (with kappa values > 0.8). Moderate to fair agreement was noted for other pathologies.

CONCLUSION

HRCT offered precise detection of the majority of pathologies, thereby facilitating surgical planning. However, the presence of limitations in distinguishing specific abnormalities highlights the significance of utilizing HRCT in tandem with other diagnostic modalities to ensure meticulous diagnosis and effective treatment planning.

Recurrence in cholesteatoma surgery: what have we learnt and where are we going? A narrative review

Treatment of cholesteatoma is surgical and has historically encompassed two main techniques: canal wall up (CWU) and canal wall down (CWD) tympanoplasty. Follow-up for cholesteatoma is still debated and can be either radiological or with second-look surgery. MRI with diffusion weighted sequences has proved to have high sensitivity and specificity in detecting recurrent or residual disease. Specifically, non-echo planar imaging DWI (non-EPI DWI) has been shown to be superior to other imaging techniques, allowing, in some cases, to avoid second-look surgery. Both residual and recurrence rates are higher in CWU compared to CWD procedures. Endoscopic ear surgery (EES) has become popular with the advantage of “looking around corners”. The endoscope is used in addition to a microscope or exclusively to reduce cholesteatoma recurrence. In addition, it has been demonstrated that mastoid obliteration and the use of potassium titanyl phosphate laser (KTP) can reduce cholesteatoma recurrence, with better functional outcomes. A synthetic sulphur compound (MESNA) may have an interesting role in the overall improvement in recurrence and residual cholesteatoma disease. This narrative review critically appraises the factors associated with the risk of recurrent cholesteatoma.

Autoincudotomy as an uncommon etiology of conductive hearing loss: Case report and review of literature

Ossicular pathology is a recognized etiology of conductive hearing loss. Ossicular pathology includes 2 main categories, that is, ossicular chain fixation and ossicular discontinuity. Ossicular discontinuity can be congenital or acquired. Auto-incudotomy is an uncommon form of acquired ossicular discontinuity that usually occurs as a sequel of spontaneous expulsion of cholesteatoma. Typically, it manifests with conductive hearing loss without evidence of cholesteatoma. In this report, we presented CT imaging finding of a 34-year-old male with tympanic membrane perforation and defective long process of the incus (auto-incudotomy) with minimal middle ear granulation tissue and adhesions, sequela of cholesteatoma. Radiologists should pay attention for evaluation of ossicles especially in patients presented with conductive hearing loss.

Utility of Non-EPI DWI MRI Imaging in Cholesteatoma: The Indian Perspective

The purpose of this prospective observational study was to evaluate the diagnostic performance of non-EPI-based techniques, in detecting both primary and residual/recurrent cholesteatoma in a tertiary care center. 56 patients (25 female and 31 male) aged between 6 and 59 years were prospectively evaluated for the presence or absence of cholesteatoma. This included both primary and postoperative recurrent cholesteatoma (16). All the patients underwent sequential CT scans of temporal bones and non-EPI DWI (Non-Echo Planar Diffusion-Weighted Imaging) MRI techniques. The findings were correlated with surgical findings regarding the presence or absence of cholesteatoma. The size of cholesteatoma that was diagnosed on non-EPI DWI MRI was measured. The smallest size was 6 mm and the largest one was 21 mm. The accuracy of non-EPI DWI MRI in diagnosing cholesteatoma (primary and recurrent) was 97.5%. Whereas in diagnosing recurrent cholesteatoma accuracy was 100%. Accuracy of non-EPI DWI MRI is very high in diagnosing cholesteatoma especially in recurrent cholesteatoma and can potentially replace second look surgery when intact canal wall techniques are used. The technique is best used with a CT Scan of the temporal bone to depict bony changes, anatomical variants, or complications. The combination of HRCT and non-EPI DWI needs to be employed in diagnosing primary and recurrent cholesteatoma to maximize the diagnostic benefit as they are complimentary.

Diagnosis and Treatment Modalities of Cholesteatomas: A Review

A cholesteatoma is an abnormal, noncancerous skin growth that can appear beneath the eardrum in the center of your ear. Although it might be a congenital condition, frequent middle ear infections are the main culprit. A cholesteatoma frequently appears as a cyst or sac that exfoliates the skin's outer layers. As these dead skin cells build up, the growth can enlarge and penetrate intratemporal tissues, leading to various intracranial and extracranial difficulties that can compromise facial muscles, hearing, and balance. Cholesteatomas were recognized more than three centuries ago. A cholesteatoma can develop into a serious condition if it is not treated right away. Because of its fast development and invasive nature, it can cause several consequences, some of which can be fatal for people without access to advanced medical treatment. There are no effective nonsurgical treatments available right now. It will be necessary to have a thorough awareness of both previous developments and more current ones to develop an appropriate management approach for this condition. The background information on acquired middle ear cholesteatomas is briefly reviewed in this paper. We also take into account categorization-, epidemiology-, histology-, and pathogenesis-related difficulties, and we carefully review current management and diagnosis approaches.

Surgical management of petrous apex cholesteatomas in the pediatric population: A systematic review

Background:

Cholesteatomas are growths of squamous epithelium that can form inside the middle ear and mastoid cavity and damage nearby structures causing hearing loss when located at the petrous apex. The primary goal of petrous apex cholesteatoma resection is gross total removal with tympanoplasty and canal-wall up or canal-wall down tympanomastoidectomy. At present, there is no definitive surgical approach supported by greater than level 4 evidence in the literature to date.

Methods:

A systematic review was conducted utilizing PubMed, Embase, and Scopus databases. Articles were screened and selected to be reviewed in full text. The articles that met inclusion criteria were reviewed for relevant data. Data analysis, means, and standard deviations were calculated using Microsoft Excel.

Results:

After screening, five articles were included in the systematic review. There were a total of eight pediatric patients with nine total cholesteatomas removed. Conductive hearing loss was the most common (77%) presenting symptom. Perforations were noted in seven ears (86%). Recurrence was noted in 50% of patients with an average recurrence rate of 3.5 years (SD = 1.73). Average length of follow-up was 32.6 months (SD = 21.7). Canal-wall up was the most utilized technique (60%) and there were zero noted surgical complications. Five of the seven (71%) patients that experienced hearing loss from perforation noted improved hearing.

Conclusion:

Due to its rarity, diagnostic evaluation and treatment can vary. Further, multi-institutional investigation is necessary to develop population-level management protocols for pediatric patients affected by petrous apex cholesteatomas.

Role of Diffusion-Weighted Magnetic Resonance Imaging in the Evaluation of Clinically Suspected Cholesteatoma Cases

To analyze the apparent diffusion coefficient (ADC) values of middle ear and mastoid lesions in Diffusion weighted Magnetic Resonance Imaging (DW-MRI) to arrive at a probable demarcating value to differentiate cholesteatoma from non-cholesteatomatous lesions. Accurate anatomic localization of the lesion was also done using High Resolution Computed Tomography (HRCT) temporal bone. The study cohort consisted of 30 patients who had undergone HRCT, DW-MRI and surgical intervention in clinically suspected cholesteatomatous lesions during the period August 2018 to August 2020.Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy values of HRCT and MRI in relation to intraoperative findings and histopathological findings (gold standard) were calculated and compared using the 2-sided McNemar's Chi Square test. Receiver operating characteristic (ROC) curve was used to predict the cut off value of ADC to differentiate between cholesteatoma and non cholesteatomatous lesions. Total patients were 30 out of which 15 were histopathologically proven cholesteatoma. MR DWI showed 100% sensitivity, 80% specificity, and 90% accuracy in diagnosing cholesteatoma compared to HPE. The probable cut off value of ADC in differentiating cholesteatoma from non-cholesteatomatous lesions was found to be < 1.226 × 10^-3 mm²/s, statistically using ROC curve. HRCT showed 96.6% accuracy in identifying the location of the lesion. MR-DWI is a useful tool both individually and in combination with HRCT in the diagnosis of cholesteatomas with high accuracy. An ADC cut-off value could also significantly help increase the accuracy of diagnosis.

Congenital aural atresia and first branchial cleft anomalies: Cholesteatoma and surgical management

Objectives

To describe the prevalence and significance of first branchial cleft anomalies in children with congenital aural atresia.

Methods

Retrospective cohort study and case series. Patients were included if they had ICD‐10 code Q16.0, Q16.1, Q16.9, Q17.2, or Q17.9 in their medical record and were seen at UCSF Benioff Children's Hospital from 2012 to 2020 for aural atresia. Children were categorized as having aural atresia and first branchial cleft anomalies if the presence of a first branchial cleft anomaly was noted in otolaryngology provider notes; otherwise, they were categorized as aural atresia alone. Patients with aural atresia and first branchial cleft anomalies were included in the case series.

Results

Among 125 children with congenital aural atresia, 5 (4%) were identified with first branchial cleft anomalies. In all cases, an epithelialized tract was noted to originate from the inferior aspect of the middle ear cleft, exiting the temporal bone in an inferomedial position adjacent to the stylomastoid foramen, with a cutaneous exit point inferior to the expected location of the native ear canal. There was no association with sex, microtia grade, or laterality of atresia; however, children with aural atresia and first branchial cleft anomalies were significantly more likely to have syndromes such as Goldenhar and Treacher Collins (p = .04) than those with aural atresia alone.

3/5 (60%) children with aural atresia and first branchial cleft anomalies presented with cholesteatoma compared with 1/120 (0.8%) children with aural atresia alone, a significant difference (p < .001). All four children over the age of two have undergone surgical management. In two of these, excision of the branchial cleft anomaly could be combined with atresiaplasty, with normal hearing results in both cases.

Conclusions

Aural atresia can be associated with comorbid anomalies of the head and neck. First branchial cleft anomalies can be suspected based on characteristic clinical appearance and confirmed with computed tomography showing a typical course through the temporal bone. When present in the context of congenital aural atresia, first branchial cleft anomalies are associated with a significantly increased risk for cholesteatoma, often necessitating surgical management with favorable hearing outcomes.

Level of evidence

4.

MRI of middle ear cholesteatoma: The importance of observer reliance from diffusion sequences

BACKGROUND AND PURPOSE

Diffusion-weighted imaging(DWI) in MRI has been developed as an important tool for the detection of cholesteatoma. Various DWI sequences are available. This study aims to evaluate the importance of the observer's reliance level for the detection of cholesteatoma.

METHODS

Forty patients meeting the following criteria were included in the study: (1) chronic otitis media, (2) preoperative MRI including various DWI sequences, and (3) middle-ear surgery. The MRI protocol contained the following sequences: (1) axial and (2) coronal echoplanar imaging (EPI) readout-segmented (RESOLVE) DWI with Trace acquisition and (3) coronal non-EPI half-Fourier acquired single-shot turbo spin-echo (HASTE) DWI. Cholesteatoma diagnosis was based on standard diagnostic criteria for cholesteatoma with DWI. Additionally, the radiologists were asked to grade personal reliance on their diagnosis using a Likert-type scale from 1 = very insecure to 5 = very secure.

RESULTS

Axial and coronal RESOLVE DWI showed a sensitivity of 77.3% and a specificity of 72.2%, respectively. The mean reliance was 3.9 for axial and 3.8 for coronal images. HASTE DWI had a sensitivity/specificity of 81.8%/66.7% with the highest reliance of all evaluated sequences (4.4). Cases with a reliance level of 5 showed a sensitivity/specificity of 100% in all sequences. A reliance level of 5 was given in the axial and coronal RESOLVE DWI in 32.5% of cases and in the HASTE DWI in 57.5%.

CONCLUSION

The evaluated DWI sequences showed comparable results. The reliance level significantly improved the predictor of cholesteatoma disease with MRI techniques.

New Navigation Approaches for Endoscopic Lateral Skull Base Surgery

Image-guided navigation is well established for surgery of the brain and anterior skull base. Although navigation workstations have been used widely by neurosurgeons and rhinologists for decades, utilization in the lateral skull base (LSB) has been less due to stricter requirements for overall accuracy less than 1 mm in this region. Endoscopic approaches to the LSB facilitate minimally invasive surgeries with less morbidity, yet there are risks of injury to critical structures. With improvements in technology over the years, image-guided navigation for endoscopic LSB surgery can reduce operative time, optimize exposure for surgical corridors, and increase safety in difficult cases.

Correlation of pre-operative computed tomography, intra-operative findings and surgical outcomes in revision tympanomastoidectomy

OBJECTIVE

To correlate pre-operative computed tomography findings, intra-operative details and surgical outcomes with cholesteatoma recurrence in revision tympanomastoidectomy.

METHODS

This retrospective, non-randomised, single-institution cohort study included 42 patients who underwent pre-operative computed tomography imaging and revision surgery for recurrent chronic otitis media. Twelve disease localisations noted during revision surgery were correlated with pre-operative temporal bone computed tomography scans. A matched pair analysis was performed on patients with similar intra-operative findings, but without pre-operative computed tomography scans.

RESULTS

Pre-operative computed tomography identified 25 out of 31 cholesteatoma recurrences. Computed tomography findings correlated with: recurrent cholesteatoma when attic opacification and ossicular chain involvement were present; and revision surgery type. Sinodural angle disease, posterior canal wall erosion and dehiscent dura were identified as predictors of canal wall down tympanomastoidectomy. Patients with pre-operative computed tomography scans had a higher rate of cholesteatoma recurrence, younger age at diagnosis of recurrent disease, more revision surgical procedures and less time between previous and revision surgical procedures (all p < 0.05).

CONCLUSION

Pre-operative imaging and intra-operative findings have important clinical implications in revision surgery for chronic otitis media. Performing pre-operative computed tomography increases diagnosis accuracy and reduces the time required to diagnose recurrent disease.

Rapid diffusion-weighted MRI for the investigation of recurrent temporal bone cholesteatoma

BACKGROUND

Suspected cholesteatoma recurrence is commonly investigated with magnetic resonance imaging (MRI) of the temporal bone. Non-echo planar diffusion-weighted imaging (non-EP DWI) has become the sequence of choice.

PURPOSE

To assess the agreement between an MRI protocol incorporating both non-EP DWI and contrast-enhanced sequences, and a shortened protocol without contrast-enhanced sequences in the assessment of suspected cholesteatoma recurrence.

MATERIALS AND METHODS

One hundred consecutive MRIs, consisting of T2-weighted, non-EP DWI and pre- and post-contrast T1-weighted sequences, were reviewed by two radiologists at a tertiary referral centre. Agreement between the two protocols was assessment by means of a weighted Cohen kappa coefficient.

RESULTS

We found a near perfect agreement between the two protocols (kappa coefficient with linear weighting 0.98; 95% confidence interval 0.95-1.00). There were two cases in which the two protocols were discordant. In both cases, the lesion measured <3 mm and images were degraded by artefact at the bone-air interface. The shortened protocol without post-contrast sequences yielded a 32% reduction in acquisition time.

CONCLUSION

When non-EP DWI is available, contrast-enhanced sequences can be omitted in the vast majority of cases without compromising diagnostic accuracy. Contrast-enhanced sequences may provide additional value in equivocal cases with small (<3 mm) lesions or in cases where images are degraded by artefact.

Imaging anatomy of the retrotympanum: variants and their surgical implications

The retrotympanic anatomy is complex and variable but has received little attention in the radiological literature. With advances in CT technology and the application of cone beam CT to temporal bone imaging, there is now a detailed depiction of the retrotympanic bony structures.With the increasing use of endoscopes in middle ear surgery, it is important for the radiologist to appreciate the nomenclature of the retrotympanic compartments in order to aid communication with the surgeon. For instance, in the context of cholesteatoma, clear imaging descriptions of retrotympanic variability and pathological involvement are valuable in pre-operative planning.The endoscopic anatomy has recently been described and the variants classified. The retrotympanum is divided into medial and lateral compartments with multiple described potential sinuses separated by bony crests.This pictorial review will describe the complex anatomy and variants of the retrotympanum. We will describe optimum reformatting techniques to demonstrate the structures of the retrotympanum and illustrate the associated anatomical landmarks and variants with CT. The implications of anatomical variants with regards to otologic surgery will be discussed.

HRCT imaging of acquired cholesteatoma: a pictorial review

Chronically discharging ear is a common cause of morbidity in developing countries, and it is also associated with intratemporal and intracranial complications. The surgeon is often able to detect the disease. However, cholesteatoma in the "hidden areas" like anterior epitympanic recess and sinus tympani can be missed. Facial nerve involvement and cholesteatomatous erosion of the bony labyrinth are dreaded complications, the extent of which cannot be assessed completely on clinical examination. Adding to the complexity are the various variations in anatomy like high riding jugular bulb and aberrant internal carotid artery which could lead to catastrophic complications during surgery if left undetected preoperatively. HRCT temporal bone is useful to detect the extent of the disease, various complications, and guide the surgeon for pre-operative planning. In this review, we go through the various HRCT imaging features of acquired cholesteatoma, a reporting template, and a few words about imaging of the post-operative ear.

Readout-Segmented Echo-Planar DWI for the Detection of Cholesteatomas: Correlation with Surgical Validation

BACKGROUND AND PURPOSE

MR imaging has become an important tool for the detection of cholesteatomas of the middle ear. Various diffusion-weighted imaging sequences are available and have shown promising results. This study aimed to evaluate readout-segmented echo-planar DWI for the detection of cholesteatoma and compare the results with surgical validation.

MATERIALS AND METHODS

Fifty patients with chronic otitis media (24 females and 26 males; range, 12-76 years of age; mean age, 41 years) who underwent MR imaging before an operation of the middle ear (1-169 days) were included. The MR imaging protocol consisted of axial and coronal readout-segmented echo-planar DWI with b-values of 0 and 1000 s/mm² and 3-mm slice thickness. The readout-segmented echo-planar diffusion-weighted images were fused with standard T2-weighted sequences for better anatomic assignment. The results of the MR imaging evaluation were correlated with the results from the operation.

RESULTS

Readout-segmented echo-planar DWI detected 22 of the 25 cases of surgically proved cholesteatoma. It has an accuracy of 92% (95% confidence interval, 80.8%-97.8%), a sensitivity of 88%, a specificity of 96%, a positive predictive value of 96%, and a negative predictive value of 89%. In 1 case, a positive finding for cholesteatoma with readout-segmented echo-planar DWI could not be proved by histology, and in 3 cases, histology yielded a cholesteatoma that was not detected with MR imaging.

CONCLUSIONS

Readout-segmented echo-planar DWI is a promising and reliable MR imaging sequence for the detection and exclusion of cholesteatoma.

Cholesteatoma Pearls: Practical Points and Update

The European Academy of Otology and Neurotology in collaboration with the Japanese Otological Society (EAONO/JOS) recently produced a joint consensus document outlining the definitions, classification and staging of middle ear cholesteatoma. The goals were to provide terminologies in the description of cholesteatoma, classify cholesteatoma into distinct categories to facilitate the comparison of surgical outcomes and to provide a staging system that reflects the severity, difficulty of complete removal and restoration of normal function. Cholesteatoma is considered a benign, expanding and destructive epithelial lesion of the temporal bone that is the result of a multifactorial process. If undetected and left treated, cholesteatoma may lead to significant complications including hearing loss, temporal bone destruction and cranial invasion. Recent advances in imaging modalities have allowed for high sensitivity and specificity in identifying the presence of cholesteatoma. Despite these advances, deficiencies exist around the world with access to health care facilities meaning cholesteatoma remains a serious and challenging entity to manage whether found within the pediatric or adult population. Proper diagnosis and management of each form of cholesteatoma is achieved by a thorough understanding of the etiology, classification, clinical presentation and histology, thereby facilitating prevention, early detection and appropriate treatment.

MRI as an Alternative to Second Look Mastoid Surgery

The main goal of surgery of cholesteatoma is eradication of the disease and revision surgery is indicated when a dry and safe ear has not been achieved. Residual cholesteatoma usually occurs at the sites that are difficult to reach with an operating microscope, such as posterior tympanum and anterior epitympanic recess. Computed tomography can be performed to delineate the extent of disease. High-resolution computed tomography scanning is important for planning for surgery and is indicated for all revision mastoid operations. Magnetic resonance imaging is superior to computed tomography in tissue characterization for diagnosis of recurrent cholesteatoma. To evaluate the cases of recurrent cholesteatoma comparing the intraoperative surgical findings with the preoperative MRI radiological findings and if the preoperative MRI can replace the second look surgery for cholesteatoma. This study was applied on 60 patients that have a recurrent cholesteatoma after previous mastoid surgery. A preoperative radiological evaluation was done by Magnetic resonance, surgical management was done by canal wall up or canal wall down mastoidectomy to exclude residual disease. Then, radiological, and surgical findings correlation was done. Diffusion-weighted MRI successfully detected 42 cases out of the 45 cases of surgically proved cholesteatoma, it has accuracy 95%, sensitivity 93.33%, specificity 100%, PPV 100% and NPV 83.33%. MRI is better than CT in tissue characterization for diagnosis of recurrent cholesteatoma, and can replace the unnecessary second look surgery of cholesteatoma.

Temporal bone computed tomography findings associated with feasibility of endoscopic ear surgery

PURPOSE

There are no formal radiologic criteria to stratify patients for transcanal (TEES) or transmastoid endoscopic ear surgery for resection of cholesteatoma. We aim to determine 1) whether standard preoperative computed tomography (CT) findings are associated with the need for conversion to a transmastoid approach and 2) the amount of time added for conversion from TEES to transmastoid techniques.

MATERIALS AND METHODS

Retrospective chart review of consecutive pediatric and adult cases of TEES for primary cholesteatoma from 2013 through 2015 (n=52). TEES cases were defined as endoscope-only procedures that did not require a transmastoid approach (n=33). Conversion cases were defined as procedures that began as TEES however, required conversion to a transmastoid approach due to the inability to complete cholesteatoma removal (n=19). Preoperative CT findings and total operating room (OR) times of TEES and conversion cases were compared.

RESULTS

Preoperative CT scan characteristics that were associated with conversion included tegmen erosion (p=0.026), malleus erosion (p<0.001), incus erosion (p=0.009), mastoid opacification (p=0.009), soft tissue opacification extending into the aditus ad antrum (p=0.009) and into antrum (p=0.006). Total OR time for TEES cases was significantly shorter than conversion cases (median 143min versus 217min, p<0.001).

CONCLUSIONS

Preoperative CT findings, notably extension of soft tissue in the aditus ad antrum, antrum and mastoid, are associated with need for conversion to transmastoid technique to achieve removal of cholesteatoma. Endoscope-only cases were significantly faster than cases that required conversion to a transmastoid approach.

Monitoring Progression of 12 Cases of Non-Operated Middle Ear Cholesteatoma With Non-Echoplanar Diffusion Weighted Magnetic Resonance Imaging: Our Experience

AIM

The aim of this study is to gain insight into the disease progression and behavior of primary cholesteatoma in a cohort of patients who did not have surgery using non-echoplanar diffusion-weighted magnetic resonance imaging (DW MRI) serial monitoring.

METHODS

Retrospective longitudinal observational study of 12 cases of middle ear cleft cholesteatoma diagnosed between 2009 and 2014 where surgery was not performed for various reasons. All cases were monitored radiologically with non-echoplanar half-Fourier acquisition single-shot turbo spin-echo diffusion weighted imaging annually for a median period of 23 months (between 11 and 45 mo) to evaluate for changes in disease volume and direction of growth.

RESULTS

Of the 12 cases, there was one outlier where the cholesteatoma growth was disproportionately high compared with the rest of the cases outside the standard deviation range. A third of the cases had radiological evidence of cholesteatoma growth. The mean growth was about 11.9% of the initial disease volume per year. Seven out of the 12 cases had radiological evidence of cholesteatoma regression in terms of size, with three cases having negative follow-up DW-MRI scans as early as 17 months. The mean regression rate was much higher than the mean growth rate at 54.3% of the initial disease volume per year. The direction of greatest growth is craniocaudally.

CONCLUSION

Within the limits of our longitudinal study, we have shown that by monitoring with non-echoplanar diffusion weighted imaging, cholesteatoma can progress or regress when left untreated by surgery. The greatest progression was recorded in the craniocaudal direction.

Chronically Discharging Ears: Evalution with High Resolution Computed Tomography

Chronic suppurative otitis media (CSOM) refers to the middle ear inflammation which is clinically characterized by the discharging ear, hearing deficit, fever and otalgia. Although a clinical diagnosis, imaging is imperative to rule out associated complications which apart from causing hearing deficit, may prove fatal at times.

Both high resolution computed tomography (HRCT) and MRI are helpful in evaluating middle ear pathologies, usage being indication specific. Due to its excellent spatial resolution, HRCT is invaluable in assessment of chronically discharging ears, especially to look for bone erosion and the integrity of the ossicles. Due to its better spatial resolution, HRCT is preferred in suspected intra temporal complications whereas MRI is more useful in evaluating intracranial extension.

Atypical radiographic features of skull base cholesterol granuloma

Cholesterol granulomas (CGs) are the most common benign lesions of the petrous apex (PA) and have distinct computed tomography (CT) and magnetic resonance imaging (MRI) characteristics. On CT, CGs of the PA (PACG) present as expansile lesions with erosion of bony trabeculae. MRI shows a hyperintense lesion on T1-and T2-weighted images and do not enhance with gadolinium. The objective is to describe the radiographic features of CGs of the skull base that do not arise from the PA. This study is a retrospective review. Three patients were operated on for suspected recurrent endolymphatic sac tumor, intracranial cholesteatoma, and recurrent sphenoid wing meningioma based on CT and MRI findings. Pathology results were consistent with CG in all three cases. All patients had bone erosion on CT. These skull base CGs did not demonstrate similar MRI features. These lesions were hyperintense, iso-to-hyperintense, and hypointense on T1-weighted MRI, respectively. These CGs were hyperintense in two cases and iso-to-hyperintense in one case on T2-weighted MRI. These lesions either demonstrated central or rim enhancement after gadolinium administration. Skull base CGs that do not arise from the PA demonstrate a broad spectrum of radiographic characteristics on MRI that are not typical of PACG.

Computed Tomography Staging of Middle Ear Cholesteatoma

Background

To establish computed tomography (CT) staging of middle ear cholesteatoma and assess its impact on the selection of the surgical procedure.

Material/Methods

Prospective study was conducted on 61 consecutive patients (mean age 26.8 years) with middle ear cholesteatoma. CT scan of the temporal bone and surgery were performed in all patients. CT staging classified cholesteatoma according to its location in the tympanic cavity (T); extension into the mastoid (M); and associated complications (C). Cholesteatoma was staged as stage I (T1, T2), stage II (T3, M1, M2, C1), and stage III (C2).

Results

The overall sensitivity of CT staging of cholesteatoma compared to surgery was 88% with excellent agreement and correlation between CT findings and intra-operative findings (K=0.863, r=0.86, P=0.001). There was excellent agreement and correlation of CT staging with surgical findings for T location (K=0.811, r=0.89, P=0.001), good for M extension (K=0.734, r=0.88, P=0.001), and excellent for associated C complications (K=1.00, r=1.0, P=0.001). Atticotympanotomy was carried out in stage I (n=14), intact canal wall surgery was performed in stage II (n=38), and canal wall down surgery was done in stage III (n=5) and stage II (n=4).

Conclusions

We established CT staging of middle ear cholesteatoma that helps surgeons to select an appropriate surgery.

Updates and knowledge gaps in cholesteatoma research

The existence of acquired cholesteatoma has been recognized for more than three centuries; however, the nature of the disorder has yet to be determined. Without timely detection and intervention, cholesteatomas can become dangerously large and invade intratemporal structures, resulting in numerous intra- and extracranial complications. Due to its aggressive growth, invasive nature, and the potentially fatal consequences of intracranial complications, acquired cholesteatoma remains a cause of morbidity and death for those who lack access to advanced medical care. Currently, no viable nonsurgical therapies are available. Developing an effective management strategy for this disorder will require a comprehensive understanding of past progress and recent advances. This paper presents a brief review of background issues related to acquired middle ear cholesteatoma and deals with practical considerations regarding the history and etymology of the disorder. We also consider issues related to the classification, epidemiology, histopathology, clinical presentation, and complications of acquired cholesteatoma and examine current diagnosis and management strategies in detail.

Diffusion weighted MR imaging of primary and recurrent middle ear cholesteatoma: an assessment by readers with different expertise

Introduction and Purpose. Diffusion weighted imaging (DWI) has been proven to be valuable in the diagnosis of middle ear cholesteatoma. The aims of our study were to evaluate the advantage of multi-shot turbo spin echo (MSh TSE) DWI compared to single-shot echo-planar (SSh EPI) DWI for the diagnosis of cholesteatoma. Material and Methods. Thirty-two patients with clinical suspicion of unilateral cholesteatoma underwent preoperative MRI (1.5T) with SSh EPI and MSh TSE. Images were separately analyzed by 4 readers with different expertise to confirm the presence of cholesteatoma. Sensitivity, specificity, diagnostic accuracy, and positive (PPV) and negative predictive values (NPV) were assessed for each observer and interrater agreement was assessed using kappa statistics. Diagnosis was obtained at surgery. Results. Overall MSh TSE showed higher diagnostic accuracy and lower negative predictive value (NPV) compared to conventional SSh EPI. Interreader agreement between the observers revealed the superiority of MSh TSE compared to SSh EPI. Interrater agreement among all the four observers was higher by using MSh TSE compared to SSh EPI. Conclusion. Our findings suggest that MSh TSE DWI has higher sensitivity for detection of cholesteatoma and lower probability of misdiagnosis. MSh TSE DWI is useful in guiding less experienced observers to the diagnosis.

Radiological assessment of the sinus tympani: temporal bone HRCT analyses and surgically related findings

PURPOSE

To evaluate the morphology of the sinus tympani (ST) based on computed tomography (CT) scans (axial view), describing the findings in a cohort of 148 patients (296 ears), and classifying the prevalence according to our ST classification. To evaluate the surgical prevalence based on the type of ST. To calculate the sensibility and positive predictive value (PPV) of high-resolution computed tomography (HRCT) scans for ST involvement by cholesteatoma.

METHODS

Retrospective review of the radiologic database and surgical reports.

RESULTS

In total, 98/296 (33.1%) middle ears presented a radiologic morphology Type A; 185/296 (62.5%) middle ears presented a radiologic morphology Type B; 13/296 (4.4%) middle ears presented a radiologic morphology Type C; HRCT showed a sensibility of 91%, specificity of 65%, PPV of 68% and negative predictive value (NPV) of 90%.

CONCLUSIONS

ST shape and depth can influence surgical preference in cholesteatoma surgery. In the case of a shallower ST, an exclusive endoscopic exploration is chosen; whereas in the case of a deeper ST, a retrofacial approach is usually preferred. HRCT scans demonstrated high sensibility and NPV for ST involvement by cholesteatoma.