Chronic otorrhea and osteomyelitis of the external auditory canal by Achromobacter xylosoxidans: an uncommon diagnosis

PURPOSE

Achromobacter xylosoxidans is an emerging pathogen mainly associated with resistant nosocomial infections. This bacteria had been isolated in the ear together with other pathogens in cultures from patients with chronic otitis media, but it had never been reported as a cause of osteomyelitis of the external auditory canal.

CASE PRESENTATION

We present a unique case of a healthy 81-year-old woman who presented with left chronic otorrhea refractory to topical and oral antibiotic treatment. Otomicroscopy revealed an erythematous and exudative external auditory canal (EAC) with scant otorrhea. The tympanic membrane was intact, but an area of bone remodeling with a small cavity anterior and inferior to the bony tympanic frame was observed. Otic culture isolated multi-drug-resistant A. xylosoxidans, only sensitive to meropenem and cotrimoxazole. Temporal bone computed tomography showed an excavation of the floor of the EAC compatible with osteomyelitis. Targeted antibiotherapy for 12 weeks was conducted, with subsequent resolution of symptoms and no progression of the bone erosion.

CONCLUSIONS

Atypical pathogens such as A. xylosoxidans can be the cause of chronic otitis externa. Early diagnosis and specific antibiotherapy can prevent the development of further complications, such as osteomyelitis. In these cases, otic cultures play an essential role to identify the causal germ. This is the first case of EAC osteomyelitis due to A. xylosoxidans reported to date.

Solitary neurofibroma in the external auditory canal

Significance Statement: Neurofibromas, derived from perineural cells, are usually benign in the nervous system. Although neurofibromas are common in the head and neck, they rarely affect the external auditory canal (EAC), and few cases have been reported. We describe a case of a solitary EAC neurofibroma with otoscopy, radiological imaging, a surgical approach, and an uneventful outcome.

[Unusual presentation of a mast cell tumor in the ear canal of a cat]

A 12-year-old male neutered European Shorthair cat was presented for pruritus in the right ear region, bleeding from ear canal and a suspected polyp-like mass in its lumen.After the diagnostic imaging a biopsy of the mass was taken and submitted for histopathological evaluation. Histopathologic examination led to the diagnosis of low grade mast cell tumor. The subsequent staging examinations included ultrasonography of the liver and spleen as well as a complete blood count. Total ear canal ablation was performed on the same day, and the removed ear canal was again submitted for histopathologic evaluation of the surgical margins. The excision incision margins were free from infiltrating tumor cells. The cat was euthanised 14 months after the surgery. It is unknown whether the reasons for this were associated to metastatic spread of the initial mast cell tumor.A mast cell tumor in the ear canal is an unusual and rare finding, however it should be included in the list of differential diagnoses for ear canal tumors.

Ganglion Cyst Presenting as an External Auditory Canal Mass

A ganglion cyst of the temporomandibular joint is a benign lesion that may present as a mass on the anterior wall of the external auditory canal and should be differentiated from other skull base pathology prior to management.

Isolated Traumatic Dislocation of the Malleus into the External Auditory Canal

We report a rare case of isolated malleus dislocation into the external auditory canal with lateralized intact tympanic membrane following a head trauma. The patient was a 63-year-old woman who presented at the outpatient department of our institute with hearing loss of 10 years' duration after a bicycle accident. During physical examination of the patient, total dislocation of the malleus-like bony structure into the external auditory canal on the right side was observed. In the computed tomography scan, an isolated malleus dislocation with intact incus-stapes articulation was identified. The patient was successfully treated with endoscopic exploratory tympanotomy and partial ossicular replacement prosthesis. The isolated malleus dislocation can rarely occur after trauma. A careful diagnostic step through history, physical examination, and temporal bone computed tomography scan are needed to confirm this rare condition.

External Ear Disease: Keratinaceous Lesions of the External Auditory Canal

Keratosis obturans (KO) and external auditory canal cholesteatoma (EACC) are two distinct keratinaceous lesions of the external ear. This article reviews the signs, symptoms, pathophysiology, workup, and treatment of each. Patients with either pathology can often be managed in the clinic with debridement; however, EACC is more likely to involve osteonecrosis and require more extensive operative management if disease is not confined to the canal on account of the bony erosion characteristic of cholesteatoma. If required for extensive disease, surgical approaches to both pathologies are similar.

Acquired Stenosis of the External Ear Canal

Acquired stenosis of the external ear canal (ASEEC) is a relatively uncommon condition. Stenosis or narrowing of the external ear canal (EEC) occurs lateral to the tympanic membrane resulting in a skin lined blind canal. Recurrent otorrhea, and conductive hearing loss are typical clinical features. Although ASEEC can be due to different etiologies, a common pathogenesis, namely an inflammatory cascade, has been implicated. Clinical evaluation, audiogram, and Computed tomography (CT scan) form the mainstay of diagnosis. Surgery is the primary modality for treatment. Restenosis is the most common postsurgical complication.

Congenital Anomalies of the Ear Canal

Congenital anomalies of the external auditory canal (EAC) are classically divided into congenital aural atresia (CAA) and congenital aural stenosis (CAS). CAA can present as an isolated anomaly, unilateral or bilateral, or in the setting of a craniofacial syndrome. Hearing testing (ABR with air and bone conduction thresholds for both ears) early in the perinatal period is important to document hearing thresholds. Hearing status thus informs parent counseling on options for hearing habilitation: Bone conducting technology is a must for children with bilateral CAA to support normal speech and language development. Bone conducting technology should be considered for children with unilateral CAA; benefits are unclear. In select candidates, atresia repair can provide improved hearing with a clean, dry, epithelialized ear canal. First branchial cleft cyst or sinus is rare; high index of suspicion is needed to diagnose along with high-resolution CT. Congenital aural stenosis (CAS) is a rare condition, and hearing testing should be similar to that in children with CAA. Early (age 4-5) CT imaging is recommended in the setting of a canal <2 mm or pinpoint canal to evaluate for trapped skin/ear canal cholesteatoma.

Modified-modified radical mastoidectomy

PURPOSE

It is unusual to have communication from the external auditory canal (EAC) directly to the mastoid, totally sparing the tympanum. These patients need a different surgical approach, a modified canal wall-down procedure, to completely clear the disease but fully preserve the tympanum. We present one such exceptional case.

CASE PRESENTATION

A 28-year-old lady presented with ear discharge for 1 year. Imaging confirmed the canal-mastoid fistula, but the entire tympanum was normal. We performed a modified-modified radical mastoidectomy.

CONCLUSIONS

Canal-mastoid fistula is an infrequent entity and may be idiopathic. Despite being evident on clinical examination, imaging aids in assessing size and location of the defect. Although EAC reconstruction may be attempted, the majority require a canal wall-down procedure.

Management of External Auditory Canal Anterior Wall Defect: A Case Series and Literature Review

OBJECTIVES

Although rare in etiology, anterior bony wall defects of the external auditory canal (EAC) accompanied by temporomandibular joint herniation may cause various otologic symptoms. Surgical treatment can be considered based on symptom severity because many previous case reports have highlighted its efficacy. This study aimed to review the long-term results of surgical treatment of EAC anterior wall defect and to suggest a stepwise approach when creating a treatment plan.

METHODS

We performed a retrospective review of 10 patients who underwent surgical management to address the EAC anterior wall defect and its associated symptoms. Medical records, temporal bone computed tomography scans, audiometry, and endoscopic examination findings were analyzed.

RESULTS

The primary repair of the EAC defect was the first to be surgically addressed in most cases, excluding one case with a severe combined infection. Of the 10 cases, 3 patients exhibited either postoperative complications or symptom recurrence. Six patients had resolved symptoms consequent to primary surgical repair, and four patients underwent revision surgery undergoing a more invasive procedure, such as canalplasty or mastoidectomy.

CONCLUSION

Primary repair of the anterior wall defect of the EAC seems to be overpromoted for lasting results but is not as promising as previously noted. We therefore propose to create a novel treatment flowchart regarding the surgical treatment of anterior wall defects of the EAC based on clinical experience.

LEVEL OF EVIDENCE

IV.

Malignant Melanoma of the External Auditory Canal on 68 Ga-FAPI PET/CT

ABSTRACT

External ear melanomas are relatively rare and usually occur in the regions of helix and ear lobes. Rarer still are primary melanomas of the external auditory canal. We report findings of melanoma of the external auditory canal on 68 Ga-FAPI PET/CT in a 56-year-old man who presented with sharp pain in the external auditory canal for 7 months.

A Rare Presentation of Primary Cutaneous Low-Grade Neuroendocrine Tumor of the External Auditory Canal

OBJECTIVE

To describe the first case of a primary cutaneous low-grade neuroendocrine tumor (cLGNET) originating from the external auditory canal as well as our team's surgical management.

PATIENT

A healthy 34-year-old female presented with a low-grade neuroendocrine tumor of her right external auditory canal (EAC) which extended from the posterior-superior aspect of the EAC into the middle ear.

INTERVENTION

A complete otological examination was performed in addition to CT and MRI imaging. The low-grade neuroendocrine tumor was surgically biopsied and further surgery was recommended for complete resection.

RESULTS

Audiogram revealed profound right sensorineural hearing loss. CT scan demonstrated complete opacification of the right EAC, middle ear, and mastoid air cells, dystrophic calcification in the mesotympanum overlying the cochlear promontory, and no associated osseous erosion. MRI revealed abnormal FLAIR hyperintensity and enhancement of the labyrinthine segment of the right facial nerve, cochlea, and horizontal and posterior semicircular canals. An enhancing mass opacifying the right EAC demonstrating restricted diffusion on diffusion-weighted image was also evident. Pathologic examination and immunohistochemical staining confirmed a diagnosis of primary cLGNET of the EAC.

CONCLUSION

Primary cLGNETs of the external ear are exceedingly rare but should be considered if an adult patient presents with a mass in the EAC. Management should include early biopsy and surgical excision followed by histological and immunohistochemical confirmation.

First branchial cleft anomaly extending to parapharyngeal space

First branchial cleft anomalies are quite rare, and the majority of them are found in and around the ear canal, mostly superficial to the facial nerve. Very rarely, the anomalous tract of the first branchial cleft can go deeper to the facial nerve, necessitating a meticulous and extensive surgery. A 21-year-old student presented with slowly increasing cystic swelling in the infra-auricular region. Findings of the magnetic resonance imaging were consistent with the first branchial cleft cyst, which also exhibited a deeper extent of the lesion into the parapharyngeal space. The entire tract was excised along with the superficial parotidectomy by an open approach. In addition to illustrating the presentation and management of this peculiar case, the present report also reviews the latest literature around their management.

Denosumab and bisphosphonate associated bilateral osteonecrosis of the external auditory canal

We present a case of non-surgically managed bilateral osteonecrosis of the external auditory canal with a history of long-term medical therapy for osteoporosis. A 79-year-old woman with severe osteoporosis and destructive osteoarthritis received >10 years of once weekly bisphosphonate therapy before switching to denosumab. Four months later, the patient presented with bilateral loss of hearing and right-sided otalgia. Necrotising otitis externa, cholesteatoma and malignancy were considered but with histology, microbiological and CT assessment, bilateral osteonecrosis of the external auditory canal was diagnosed. Surgical debridement with canalplasty was avoided due to our patient's comorbidities. Treatment continued for 5 months with regular aural toilet, Terra-Cortril ointment and bismuth-iodine-paraffin paste packing. At 1-year follow-up, bilateral external auditory canals were completely re-epithelialised with no pain or affected hearing. We report the first case of bilateral osteonecrosis of the external auditory canal associated with denosumab and bisphosphonates with successful conservative management.

Tolerance and safety of 45S5 bioactive glass used in obliteration procedures during middle ear surgery: Preliminary results

OBJECTIVE

Otologists face many disadvantages after extensive mastoid drilling and canal wall down technique in cholesteatoma surgery. Mastoid and epitympanic cavity obliterations or reconstructions after canal wall down procedure using bioactive glass seem to be an interesting solution to overcome some of these disadvantages. Bioactive glass offers many benefits including the availability when there are no sufficient autologous materials for obliteration, its antibacterial activity in chronic infected ear and decreasing the recidivism of cholesteatoma. The objective of this study is to evaluate the tolerance and safety of 45S5 bioactive glass as a filing bone-synthetic material by clinical, audiological and radiological examinations.

METHODOLOGY

A retrospective study of 42 patients who had undergone obliteration of mastoid or/and epitympanic cavity with 45S5 bioactive glass between, November 2017 to January 2019. Data from clinical follow-ups, audiological assessment, CT-scan and MRI were analyzed.

RESULT

The patients' mean age was 49.8 years old. Microscopic examinations showed dry well-healed tympanic membranes and external auditory canals for 95.2% of the patients after 1 year. Inner ear injuries after obliteration were not observed by comparing pre and post-operative bone conduction audiometry (p value 0.457). No facial palsy was reported post-operatively. One-year postoperative radiological assessments did not reveal any silent implantation of cholesteatoma or residual disease.

CONCLUSION

Mastoid and epitympanic obliterations with 45S5 bioactive glass seem to be a tolerable and safe option in cholesteatoma surgery with favorable outcomes similar to other member of bioactive glass especially the S53P4.

Extrapulmonary small cell carcinoma of the external auditory canal: a case report and review of the literature

Extrapulmonary small cell carcinoma (EPSCC) affecting the external auditory canal (EAC) is uncommon. We herein report a case involving a 56-year-old man with EPSCC of the EAC who had a 48-year history of recurrent purulent discharge in both ears and a 20-day history of right ear pain and hemorrhage followed by incomplete right eyelid closure and an askew mouth. He underwent surgical removal of middle ear granulation tissue, residual ossicles, and a right EAC mass. Postoperatively, pathomorphological examination combined with immunohistochemical staining supported a diagnosis of small cell carcinoma. Radiation therapy at a dose of 60.06 Gy in 33 daily fractions was completed 1 month after surgery, and synchronous etoposide-cisplatin regimen chemotherapy was performed for two cycles and four sequential cycles. One year postoperatively, magnetic resonance imaging showed no tumor in the ear; however, computed tomography showed multiple liver space-occupying lesions that were considered to indicate liver metastasis. Further chemotherapy was performed, but the patient died 15 months postoperatively. This case indicates that timely and accurate chemoradiotherapy is likely the most reasonable approach to EPSCC of the EAC given the aggressiveness of this tumor.

Reproducing ear-canal reflectance using two measurement techniques in adult ears

Clinical diagnostic applications of ear-canal reflectance have been researched extensively in the literature, however, the measurement uncertainty associated with the conventional measurement technique using an insert ear probe is unknown in human ear canals. Ear-canal reflectance measured using an ear probe is affected by multiple sources of error, including incorrect estimates of the ear-canal cross-sectional area and oblique ear-probe insertions. In this paper, ear-canal reflectance measurements are reproduced in an occluded-ear simulator and in 54 adult ear canals using two different measurement techniques: a conventional ear probe and a two-microphone probe that enables the separation of reverse- and forward-propagating plane waves. The two-microphone probe is inserted directly into test subjects' ear canals, and the two-microphone method is distinguished by not requiring the ear-canal cross-sectional area to calculate the ear-canal reflectance. The results show a reasonable agreement between the two measurement techniques. The paper further examines the influence of oblique ear-probe insertions and the compensation for such oblique insertions, which results in an improved agreement between the two measurement techniques.

Neuroimaging findings in Emanuel Syndrome

Emanuel syndrome is a rare inherited chromosomal abnormality caused by an unbalanced translocation of chromosomes 11 and 22. Clinically, Emanuel syndrome is characterized by a wide spectrum of congenital anomalies, dysmorphisms, and developmental disability often confused with other similar syndromes. Outside of genetic testing, diagnosis remains challenging and current literature on typical radiologic findings is limited. We present classic neuroimaging findings of Emanuel syndrome consistent with prior literature including microcephaly, microretrognathia, external auditory canal stenosis, and cleft palate; and also introduce the additional maxillofacial anomaly of dysplastic middle ear ossicles, to our knowledge not previously described in the literature. Recognition of findings leading to earlier diagnosis of Emanuel syndrome may improve outcomes and quality of life for patients and their families.

Use of magnetic resonance image registration to estimate displacement in the human earcanal due to the insertion of in-ear devices

In-ear devices are used in a wide range of applications for which the device's usability and/or efficiency is strongly related to comfort aspects that are influenced by the mechanical interaction between the device and the walls of the earcanal. Although the displacement of the earcanal walls due to the insertion of the device is an important characteristic of this interaction, existing studies on this subject are very limited. This paper proposes a method to estimate this displacement in vivo using a registration technique on magnetic resonance images. The amplitude, the location and the direction of the earcanal wall displacement are computed for four types of earplugs used by one participant. These displacements give indications on how each earplug deforms the earcanal for one specific earcanal geometry and one specific earplug insertion. Although the displacement due to a specific earplug family cannot be generalized using the results of this paper, the latter help to understand where, how much, and how each studied earplug deforms the earcanal of the participant. This method is revealed as a promising tool to investigate further acoustical and physical comfort aspects of in-ear devices.

Unusual case of unilateral conductive hearing loss: chronic lymphocytic leukaemia

This presentation reports a novel case of chronic lymphocytic leukaemia (CLL), presenting with an early cutaneous lesion within the external auditory canal, in a patient being assessed for conductive hearing loss. It has previously been reported that infiltrative CLL can involve the head and neck; however, isolated external ear canal involvement is rare. Given that the incidence of CLL in Australia is rising, this case highlights the importance of considering CLL as a differential diagnosis for presentations of unilateral conductive hearing loss.

The Clinical Characteristics and Surgical Outcomes of Carcinoma of the External Auditory Canal: A Multicenter Study

OBJECTIVE

To analyze the clinical characteristics and evaluate the surgical outcomes of carcinoma of the external auditory canal (CEAC).

MATERIALS AND METHODS

Overall, 31 patients from four multicenter hospitals, who were diagnosed and surgically treated for CEAC in 2009-2014, were enrolled for this retrospective study. Medical records were reviewed to determine cancer stage according to the Pittsburgh classification. Clinical data of age, sex, site, initial symptoms, surgery extent, postoperative complications including recurrence, follow-up period, and current patient status were collected for analysis. Five-year cumulative survival rate was obtained using Kaplan-Meier method.

RESULTS

At initial diagnosis, 22 patients were in the early stages (stage I: 15; stage II: 7) and 9 patients were in the advanced stages (stage III: 1; stage IV: 8). Lymph node metastasis was present in 5 patients and distant metastasis in 2. Of the 31 patients, 4 patients died (stage II: 1, stage IV: 3) during the follow-up period. Early-stage patients showed 100% 5-year estimated cumulative survival rate, whereas the advanced-stage patients showed 5-year estimated survival rate of 53.6% (p=.006). The overall survival rate of all enrolled patients was 90.3%. Although 5-year estimated disease-free survival rate of stage I was 100.0%, that for stage II was low at 30.0% because of considerable recurrences.

CONCLUSION

The results of this multicenter study suggest that more aggressive treatment modality, including adjuvant therapy, is necessary for patients with CEAC with Pittsburgh stage II or more.

Correlation among external auditory canal anomaly, temporal bone malformation, and hearing levels in patients with microtia

We conducted a retrospective study to evaluate the relationship between external auditory canal (EAC) anomaly, temporal bone abnormality, and hearing levels using objective scoring systems in Chinese patients with microtia. The study population consisted of 106 ears of 94 Chinese patients (67 male and 27 female) aged 5 to 45 years (mean: 12.6) with microtia. The EAC abnormalities were classified into 4 types according to Schuknecht's criteria: type A, type B, type C, and type D. Developmental anomalies of the temporal bone were evaluated by Jahrsdoerfer computed tomography (CT) scoring system using high-resolution CT scans of the temporal bone. Temporal bone malformation parameters were divided into 4 subgroups: ossicular chain development, windows connected to the cochlea, aeration development of the middle ear, and facial nerve aberration. Hearing levels (air conduction and bone conduction) were examined. Outcomes parameters included correlation coefficients (r) and a number of other variables. The total points (10 points) and subtotal points related to ossicles (4 points), windows (2 points), aeration (2 points), and facial nerve (1 point) correlated inversely with the EAC abnormalities. The hearing levels (air conduction, r = 0.396, p <0.01; bone conduction, r = 0.21, p = 0.03) correlated significantly with the EAC abnormalities of Schuknecht's classification. We conclude that the better developed the external auditory canal, the better developed the temporal bone and the better developed the external auditory canal, the better hearing level. The hearing level also can serve as an indicator to determine whether a patient will be suitable for reconstructive surgery.

Intracanalicular vestibular schwannomas presenting with facial nerve paralysis

BACKGROUND

To describe the surgical management and postoperative course of two patients presenting with facial nerve (FN) paralysis as one of the presenting symptoms of small intracanalicular vestibular schwannomas (VS).

METHODS

Among 153 patients operated for VS since September 2010 to August 2017, two adult female patients presented with rapidly progressive hearing decrease, vestibular symptoms, and FN paralysis (House-Brackmann grades III and IV, respectively). In both cases, c.e. T1-weighted magnetic resonance imaging revealed an enhancing tumor within the internal auditory canal without lateral extension beyond the fundus.

RESULTS

Retrosigmoid approach and excision of tumor showed that the origin of tumor was from the superior vestibular nerve, extrinsic to FN. Gross total tumor resection was obtained, with FN preservation. In the first case, a millimetric fragment of capsule was left because of tight adhesion on FN itself. Histopathology confirmed schwannoma. After surgery, both patients improved FN motor function.

CONCLUSIONS

Although very rarely, VS may start clinically with FN palsy, mimicking FN schwannomas and other less common pathologies. This presentation is exceptional in patients with small intracanalicular VS. Early surgical resection is the only reliable treatment for decompression of nerve, avoiding a complete and not-reversible damage, with possible postoperative FN function improvement or complete recovery.

A novel method to measure the external auditory canal: Normative data and practical implications

PURPOSE

To accurately measure external auditory canal (EAC) dimensions by high resolution computed tomography (CT), and compare results with a traditional method of EAC measurement.

METHODS

Using an advanced multidimensional open source digital imaging and communications in medicine (DICOM) analysis program (OsiriX, Pixmeo, Geneva, Switzerland) 91 adult EACs were analyzed on a previously obtained temporal bone CT scan. Tympanometric data were also recorded for each ear. The methods were compared using a linear mixed effect model.

RESULTS

EAC volume was compared between tympanometrically calculated volumes and CT measured volumes. It was found that CT measured volumes are, on average, smaller (1.12cm³, SE=0.04) than tympanometry volumes (1.27cm³, SE=0.04cm³). There was a significant difference in CT measured volume between genders (p=0.0125), with males having larger measured volumes (1.23cm³, SD=0.28cm³) than females (1.06cm³, SD=0.20cm³). There was a significant difference in average circumference between ear laterality (p=0.0071), with the right ear having a slightly larger average circumference (2.49cm, SD=0.23cm) than the left ear (2.44cm, SD=0.50cm).There was also a significant difference in minimum circumference between age groups (p=0.0448), with patients younger than 60years having larger minimum circumferences (1.89cm, SD=0.21cm) than older patients (1.78cm, SD=0.25cm).

CONCLUSIONS

This study demonstrates that CT analysis can provide more information about EAC dimensions than traditional techniques. Moreover, slight but statistically significant differences are associated with age, gender and laterality. Accurate estimation of EAC dimensions is important for the development of hearing aids and personal protective equipment and can also be helpful for surgical planning, specifically otoendoscopy. Future research will focus on simplifying computation, developing cross-cultural cohort comparisons, and application to otoendoscopic procedures.

Recidivous cholesteatoma: DWI MR after canal wall up and canal wall down mastoidectomy

OBJECTIVES

To investigate the correlation between preoperative non-echo planar diffusion-weighted (non-EPI DWI) MR imaging with surgical findings of recidivous middle ear cholesteatoma after canal wall up (CWU) and canal wall down (CWD) mastoidectomy.

BACKGROUND

The detection of recidive cholesteatoma after CWU and after CWD procedures, when the trepanation cavity is spontaneously closed by soft tissue, is possible by second-look and revision surgery. However, many cases prove to be negative of the disease. To avoid unnecessary operational risks we adopted a novel imaging method to evaluate its potential in the detection of recidivous cholesteatoma.

MATERIAL AND METHODS

The prospective study included 27 cases. Fifteen cases were revised after CWD and 12 cases were second-look surgeries after CWU procedures. All patients underwent the MR protocol: T2-weighted, T1-weighted and non-EPI DWI. The finding on MR correlated with peroperative presence of cholesteatoma.

RESULTS

Non-EPI DWI sequence showed an increased signal intensity in 16/27 (59 %) cases. This correlated with surgical findings in all 7 patients after CWU and in 8 patients after CWD. The overall sensitivity, specificity, positive and negative predictive values of non-EPI DWI were 83.3 %, 88.8 %, 93.8 % and 72.7 %, respectively. DWI presented a sensitivity of 100 % and specificity of 85.7 % in the subgroup of patients after CWD mastoidectomy.

CONCLUSION

Residual and/or recurrent cholesteatoma can be accurately detected by DWI MR. It can be used as a screening method to select patients, who are indicated to second-look or revision surgery after CWU and CWD mastoidectomy (Tab. 1, Fig. 3, Ref. 49).

Bilateral microtia, canal atresia and aplasia of cochleovestibular nerve

A six-month-old baby with congenital patent ductus arteriosus (PDA), bilateral microtia and canal atresia was referred for hearing assessment. The audiology assessment revealed bilateral profound hearing loss, which is atypical for a case of pure canal atresia. Imaging was performed much earlier than usual and, as suspected, the patient also had bilateral severe inner ear anomaly. It is extremely rare for a person to have both external and inner ear anomaly because of the different embryological origin. The only suitable hearing rehabilitation option for this kind of patients is brainstem implant. However, the parents had opted for sign language as a form of communication.

Shope Fibroma in the External Ear Canal of a Domestic Rabbit

A 5-y-old, intact, 2.5-kg female domestic rabbit was presented because of blood spatter on the wall of its cage and the toenails of its right hind limb. Physical examination revealed a red, gelatinous mass that spanned the width of the right vertical ear canal. Radiographic images revealed a soft-tissue opacity at the base of the right ear, which was superimposed over the tympanic bulla and extended to the pinna. A CT scan revealed that the soft-tissue mass was within the vertical and horizontal portions of the right external ear canal and extended to the level of the tympanic membrane, with no bony involvement. An incisional biopsy of the mass and subsequent histopathology revealed heterophilic inflammation with bacteria, necrosis, and no evidence of neoplasia. The patient died during anesthesia for removal of the mass at 1 mo after the initial presentation. Necropsy with histopathology of the mass was consistent with Shope fibroma virus in light of the presence of typical intracytoplasmic eosinophilic inclusions. Electron microscopy of paraffin-embedded tissue revealed electron-dense intracytoplasmic structures within neoplastic cells consistent with the diagnosis of Leporipoxvirus. To our knowledge, this report is the first description of Shope fibroma virus invading the external ear canal of a domestic rabbit. Given the results of this case, Shope fibroma should be considered in rabbits presenting with abnormal tissue in the ear canal.

Visual perception of the osseous labyrinth rendered from micro-CT scans of the petrous bone

Grayscale images comparing to the color images may have less of visual information necessary for easy recognition of the anatomical structures. Although micro-CT scanners deliver images of ultra-high resolution, application of false-colors to the rendered structures enhance their visual perception and allow for quick delineation between them and surrounding bony matrix. This paper presents differences of imaging of the osseous structures of the inner ear labyrinth using pseudo-color volume rendering in contrast to grayscale volume rendering of the micro-CT data. Applied procedures of image processing improved significantly delineation between the bony matrix surrounding the cochlea and vestibule rendered in the pseudo-colors than in grayscale.

[The spontaneous herniation of temporomandibular joint into external auditory canal: diagnosis of otoscopy, CT and MRI]

OBJECTIVE

To summarize the otoscopy, CT and MRI features of spontaneous herniation of the temporomandibular joint(TMJ) into the external auditory canal(EAC) through the persistence Huschke's foramen(PHF).

METHODS

The otoscopy, CT and MRI images of three cases with the herniation of the TMJ into the EAC through the PHF were analyzed retrospectively.

RESULTS

Otoscopy revealed the masses located in the antero-inferior aspect of the bony EAC, and the mass displayed an alternative of forward and backward motion during opening and closing of the mouth.CT of the temporal bone showed a bony defect and a consecutive soft mass in the antero-inferior wall of the bony EAC. The margin of the bony defects were well-defined in all cases, the bone adjacent to PHF was pressed and partially wrapped around the soft mass as 'holding ball' in two cases, partly peripheral pseudo bony shell of the soft mass were showed in two cases. The soft mass in EAC appeared equal attenuated with the soft tissue of TMJ, and on enhanced CT scans showed no enhancement of the soft mass. On MRI scans, the imaging displayed a bony defect in the antero-inferior wall of the EAC with a soft mass which was formed by the capsule of the TMJ, and the mass showed iso-signal to the capsule of the TMJ on all sequences, and there was no enhancement after contrast administration.

CONCLUSION

The otoscopy, CT and MRI features of the spontaneous herniation of the TMJ into the EAC through the PHF is special, and the above examinations are valuable for diagnosis of the disease.

Ultrasonographic localization of the thyroid gland for its optimal shielding prior to lateral cephalometric radiography: a pilot study

OBJECTIVES

Lateral cephalometric radiography is a common radiographic examination technique in children. The exclusion of the thyroid gland from the primary X-ray beam is important especially with children. However, patient treatment might require displaying the four most cranial cervical vertebrae (C1-C4) for the assessment of cervical vertebral maturation. Our aim was to present a safe way to display C1-C4 and exclude the thyroid gland from the X-ray beam during lateral cephalometric radiography.

METHODS

The thyroid glands of 25, 7- to 12-year-old patients were localized by ultrasound examination and shielded prior to lateral cephalometric radiography. A roentgen-positive mark was taped on the patient's skin at the level of most cranial level of the thyroid gland in the midsagittal plane. After exposure, each lateral cephalometric radiograph (LCR) was analyzed for the visibility of the cervical vertebrae. The distance between the ear post and the highest edge of the thyroid shield (TS) at the lateral part of the neck was measured and compared with the distance between the centre of the radiological external auditory meatus, and a roentgen-positive mark was made on the LCR.

RESULTS

68% of the LCRs displayed C1-C4, and the rest of them displayed C1-C3. In all of the patients, the highest edge of the TS in the lateral parts of the neck was located in a higher position than the actual most cranial level of the thyroid gland.

CONCLUSIONS

Despite localizing the thyroid gland prior to lateral cephalometric radiography, simultaneous visualization of C1-C4 and exclusion of the thyroid gland from the primary X-ray beam during lateral cephalometric radiography might not be completely possible in children because of the design and poor fitness of the TS.

Radiological Findings of Malignant Tumors of External Auditory Canal: A Cross-Sectional Study Between Squamous Cell Carcinoma and Adenocarcinoma

The primary malignant tumors of external auditory canal (EAC) are rare. The purpose of this study is to compare the imaging features of growth and recurrence pattern between 2 most common carcinomas namely squamous cell carcinoma (SCC) and adenocarcinoma of the EAC.This is a retrospective study involving 41 patients with primary EAC carcinomas of which 22 are SCC and 19 are adenocarcinoma. They were all scanned with high resolution computer tomography (HRCT) and magnetic resonance imaging. Follow-up clinical and imaging studies have also been collected and compared with a median follow-up time of 43 months (range 5-192 months). Necrosis was presented as hypodensity on computed tomography images, hyper-intense on T2WI and heterogeneous enhancement.Eighteen patients were diagnosed to be in T1 and T2 stage, it was found that SCC involved both the cartilaginous part and the bony part of the EAC (11/12), whereas adenocarcinoma involved only the cartilaginous part (6/6) (P < 0.01). Twenty-three patients were diagnosed to be in T3 and T4 stage showed bony involvement and adjacent tissue involvement for both SCC and adenocarcinoma. Parapharyngeal space involvement is much more common in recurrent SCC (P = 0.02). Lymph node metastasis was seen in 6 out of 22 patients with SCC, while 5 out of 19 patients of adenocarcinoma had lung metastasis, even at early stage (1/6; 1/5). Necrosis is more likely to occur in the patients with SCC (9/10) than that of adenocarcinoma (3/13) (P = 0.02).SCC and adenocarcinoma is seen to have different growth pattern at early stage but share similar patterns in the advanced stage. Lymph node metastasis is commonly seen in patients with SCC while adenocarcinoma shows lung metastasis even at early stage.

Electrode array extrusion through the posterior canal wall presenting as a delayed post-cochlear implant complication

OBJECTIVES AND IMPORTANCE: Cochlear implantation is an established, reliable, and safe procedure with a low complication rate. Electrode array extrusion through the posterior aspect of external ear canal is a potential major complication of cochlear implant surgery that may result in revision surgery or explantation. Although there have been previous case reports of such extrusions through the tympanic membrane, this is the first well-documented report of an extrusion through the posterior canal wall which was previously intact.

CLINICAL PRESENTATION

In this case report, we present a case of electrode array extruding through an initially intact posterior canal wall presenting as a delayed post-operative complication in a 13-year old Asian boy.

INTERVENTION

With reference to existing relevant literature, the case is discussed focusing on its management, possible contributing factors, and prevention strategies.

CONCLUSION

Excessive thinning of the bony wall should be avoided as it can potentially break down. Abutment on the posterior canal wall by a coiled electrode array in the mastoid cavity exerting undue pressure on the bony wall can further contribute to additional stress. The implant surgeon must be cognizant of mastoid growth patterns in children. Life-long regular follow-up in implanted patients is crucial.

The Pitfalls and Important Distances in Temporal Bone HRCT of the Subjects with High Jugular Bulbs - Preliminary Report

BACKGROUND

High jugular bulb (HJB) may be detected unilaterally or bilaterally in temporal bone high resolution computerized tomography (HRCT).

OBJECTIVES

In this retrospective study, we investigated the pitfalls and important surgical distances in patients with unilateral and bilateral HJB via temporal bone HRCT.

MATERIAL AND METHODS

In this preliminary report, the study group consisted of 20 adult patients (12 male, 8 female), or 40 ears, all of which underwent temporal bone HRCT. We divided them into groups that consisted of bilateral HJB (14 ears), unilateral HJB (13 ears), and control (No HJB, 13 ears). The anotomical relationships of the sigmoid sinus, jugular bulb, and carotid artery with several landmarks in the temporal bone were studied via temporal bone axial and coronal HRCT. The shortest distances between certain points were measured. These measurements were analyzed in respect to pneumatization. Dehiscence on the jugular bulb (JB) and internal carotid artery (ICA) and the dominance of JB were also evaluated for all of the groups.

RESULTS

In the axial sections of the temporal bone HRCTs, the sigmois sinus (SS)-external auditory canal (EAC) distance of the bilateral HJB group (14.00±1.17 mm) was significantly lower than that of the control group (16.46±2.14 mm). The JB-posteromedial points of the umbo on the ear drum (ED) distance of the bilateral HJB (6.28±1.72 mm) and the unilateral HJB groups (7.23±2.00 mm) were significantly lower than that of the control group (11.15±2.30 mm). In the coronal sections of the temporal bone HRCT, the JB-F distance of the bilateral HJB group (5.42±2.10 mm) was significantly lower than that of the control group (8.30±2.28 mm). As the mastoid pneumatisation and mastoid volume increased, the percentage of ICA-dehiscence and the percentage of JB-dehiscence increased.

CONCLUSIONS

In subjects with well-pneumatised mastoids, the doctors should be aware of the increased risk of ICA-dehiscence and JB-dehiscence. These measurements should be done in greater series to yield more thorough knowledge.

A three-dimensional morphometric study on the position of temporomandibular joints

OBJECTIVES

To address the controversy, in which indications average value articulation is suitable or to what extent individual registrations, especially using the facebow, should be applied, a quantification of the variability of relevant anatomical landmarks is necessary. The goal of this study was to investigate the mean and natural bandwidth of the parameters describing articulation.

METHODS

Significant landmarks were measured on three-dimensional (3D) cone beam computed tomography (CBCT) scans of 120 arbitrarily selected individuals. The bandwidth and mean values of the anatomical relations were calculated.

RESULTS

The mean arm length of the Bonwill triangle was 103.3 mm, with a range of 90.2 mm (minimum) to 117.9 mm (maximum), and a mean base length of 99.6 mm, with a range of 85.2 mm to 112.6 mm. There was a high correlation between the length of the left and right arms, but not between the arms and the base. The mean height of the Bonwill triangle, measured between the condyles and the occlusal plane, resulted in 34.3 mm, with a range of 21.0 mm to 47.2 mm. The mean value of the Balkwill angle was 20.4 degrees, with a range of 9.0 degrees to 27.6 degrees. The angle between the Camper's line and the occlusal plane averaged around 7 degrees.

CONCLUSIONS

This study presents the bandwidth of anatomical relations necessary for articulation systems. The results are specific for males and females. The relevant parameters offer a high symmetry between the right and left sides. Additionally, the results show that the Bonwill triangle is more likely to be isosceles than equilateral.

CLINICAL SIGNIFICANCE

The knowledge of the anatomical bandwidth of temporomandibular joint (TMJ) positions in relation to the dentition allows the simulation of software- controlled virtual articulators and the substitution of facebows.

[Myeloidleukemia with external auditory canal granulocytic sarcoma: a case report]

We describe a 44-year old man who suffered an isolated external auditory canal granulocytic sarcoma in remission of acute myeloid leukemia. The patient confirmed acute promyelocytic leukemia three years ago and the disease was in remission after treatment. Two months ago he presented pain and hearing loss in the left ear and the symptom developed gradually. At otoscopic examination a tumoral lesion was noted in the external auditory canal and computerized tomography scan showed a mass in the left external acoustic meatus without bone erosion.

The extent of inferior displacement of the mastoid tegmen is related to the severity of congenital aural atresia

CONCLUSION

The extent of inferior displacement of the mastoid tegmen is related to the severity of congenital aural atresia (CAA).

OBJECTIVE

To analyze anatomic variations observed on high-resolution temporal bone computed tomography (TBCT) in patients with CAA, the extent of inferior displacement of the mastoid tegmen and the size of the incudo-stapedial (IS) joint angle were compared with surgical parameters for atresiaplasty, such as Jahrsdoerfer score and hearing acuity.

METHODS

Sixty-one patients with unilateral CAA underwent high-resolution TBCT and hearing tests. We evaluated TBCTs in terms of Jahrsdoerfer criteria and analyzed the relationships among the inferior displacement of the mastoid tegmen, size of the IS joint angle, hearing acuity, and the Jahrsdoerfer score on the atretic side.

RESULTS

IS joint angle on the atretic side was found to be 120.6 ± 11°, which was significantly greater than the corresponding value of 103.4 ± 5.4° on the normal side. Cholesteatoma occurred significantly more often in CAA patients with narrow external auditory canals (EACs) (9/27; 33.3%), compared with CAA patients with no EAC opening (2/34; 5.9%). There was a significant relation between the extent of inferior displacement of the mastoid tegmen (28.9% in the atretic side and 17.3% in the normal side) and the Jahrsdoerfer score (p < 0.0001).

Validation of anatomically shaped cranial collimation (ACC) in orthodontic lateral cephalography

The use of an anatomically shaped cranial collimator (ACC) to reduce patient dose in orthodontic lateral cephalography was investigated in this study. The aim was to evaluate the potential interference of the ACC on landmark identification for orthodontic cephalometry. Consecutive orthodontic patients underwent a total of 100 cephalograms using an ACC mounted on a Veraviewepocs(®) 3D X550 (J. Morita Co., Kyoto, Japan) X-ray unit. 10 observers were asked whether the identification of 5 landmarks close to the collimated area was hindered or rendered impossible by the presence of the collimator. Of the 500 landmarks that were judged by the 10 observers, 496 (99.2%) were reported to lack hindrance. In three landmarks, a minority of the observers reported hindrance. In 1 landmark, 8 of the 10 observers reported hindrance by the collimator. In no instance did the observers state that the identification of landmarks was impossible as a result of the collimation. Application of the ACC on the cephalostat of the X-ray unit is a viable way of reducing patient dose, as it only marginally interferes with the diagnostic yield of the exposure. The need to retake images when the ACC is applied was found to be extremely low.

Clinical characteristics of spontaneous cholesteatoma of the external auditory canal in children comparing with cholesteatoma in adults

The purpose of this study was to investigate the characteristics of external auditory canal cholesteatoma (EACC) in children through evaluation of the clinical and radiologic features as well as treatment outcomes. The clinical records were retrospectively reviewed for children under 15 years of age diagnosed with spontaneous EACC between March 2004 and December 2011. The clinical data of adults diagnosed with spontaneous EACC during the same period were evaluated to compare with EACC in children. Eight patients (3 males and 5 females) with pediatric EACC and 18 patients (7 males and 11 females, 20 ears) with adult EACC were included within the boundary of the study. The mean ages were 12.4 years (age range 9-15) for pediatric EACC and 49.8 years (age range 29-79) for adult EACC patients. Follow-up periods ranged from 8 to 86 months (mean 32.5 ± 8.62) in pediatric EACC and from 6 to 72 months (mean 22.2 ± 5.36) in adult EACC. Pediatric EACC, showed involvement most commonly in the posterior wall, while the inferior wall was most commonly involved in adult EACC. Pediatric EACC tended to show a more focal involvement and was not as extensive as adult EACC. Extension into the adjacent structures was similar in both groups, but bony destruction was more common in the adult group. Two children and eight adult patients were treated with surgery, but four adult cases needed more extensive surgical treatment because their disease was widely spread to included areas such as the mastoid segment of facial nerve and the temporomandibular joint. Six pediatric cases treated with conservative management showed no progression of disease on physical examination at the last visit, but two cases of adults progressed and required canaloplasty. Pediatric EACC shows less aggressive behavior compared to adult EACC. Adequate management may work better in pediatric than in adult EACC, even though the treatment modality is conservative management.