Melanoma of the external auditory canal: case report and systematic literature review.

Melanoma of the external auditory canal (EAC) is particularly rare and poorly understood, with limited available data on management and survival. This systematic review aims to analyze existing data and provide insights into the management and prognosis the beginning of EAC melanoma. It is conducted using Pubmed and Scopus databases from the beginning to July 2023 and it follows the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines. Searches are performed using the search string "(melanoma) AND (external auditory canal)".The review includes a total of 30 patients diagnosed with EAC melanoma, supplemented by an additional case from the authors' clinical experience. The role of Breslow thickness as a determining factor for the choice of surgery remains inconclusive due to limited available data. Sentinel lymph node biopsy and adjuvant therapy are sparingly employed, indicating the need for standardized guidelines. Patients in the study demonstrate a 50% overall survival rate at 5 years.EAC Melanoma is a rare and aggressive malignancy with limited therapeutic guidelines. Surgical interventions, including wide local excision and lateral temporal bone resection, are the primary treatment options for patients without distant metastases.

Action of mycocins produced by Wickerhamomyces anomalus on Malassezia pachydermatis isolated from the ear canal of dogs.

This study aims to examine the effectiveness of mycocins produced by Wickerhamomyces anomalus in inhibiting Malassezia pachydermatis, a yeast commonly found in the ear canal of dogs. M. pachydermatis has a zoophilic origin and can be found in mammals, and frequently in dogs, where it mainly colonizes the ear canal region and the skin, leading to lesions that are difficult to treat. The antimicrobial mechanism was evaluated using dilutions of supernatant with enzymatic activity, which may include ß-glucanases, glycoproteins known to act on microorganism cell walls. However, it is important to note that this supernatant may contain other compounds as well. ß-glucanases in the mycocins supernatant were found at a concentration of 0.8 U/mg. The susceptibility of M. pachydermatis isolates was tested using the microdilution method. The isolates suffered 100% inhibition when tested with the culture supernatant containing mycocins. In the proteinases production test, 44% of the isolates tested were strong proteinases producers. Subsequently all these isolates suffered inhibition of their activity when tested in research medium containing mycocins supernatant at a subinhibitory concentration of ß-glucanases. This shows that mycocins can inhibit the production of proteinases, a virulence factor of M. pachydermatis. The viability test showed the antifungal action of mycocins in inhibiting the viability of M. pachydermatis cells after a period of 8  hours of contact. These results support the antimicrobial potential of mycocins and their promise as a therapeutic option.

Microbiome of the External Auditory Canal: Changes After Long-Term Hearing Aid Use.

OBJECTIVE: To investigate the microbial changes of long-term hearing aid use culture independently. STUDY DESIGN: Cross-sectional study. PATIENTS: Fifty long-term hearing aid users and 80 volunteer controls with asymptomatic ears. INTERVENTION: External auditory canal (EAC) sampling with DNA-free swabs. MAIN OUTCOME MEASURES: Microbial communities in the samples were investigated with amplicon sequencing of the 16S rRNA gene. RESULTS: The final analysis contained 48 hearing aid users, 59 controls. Twenty-four samples were excluded because of low sequence count, recent use of antimicrobials and/or corticosteroids, recent cold, or missing health status. The groups showed significant differences in bacterial diversity (beta div., p = 0.011), and hearing aid users showed lower species richness than the control group (alpha div., p < 0.01). The most frequent findings in both groups were Staphylococcus auricularis , Alloiococcus otitis , Cutibacterium acnes , Corynebacterium otitidis , and Staphylococcus unclassified sp. Hearing aid users' samples presented more Corynebacterium tuberculostearicum than the control samples. Common EAC pathogens, such as Staphylococcus aureus or Pseudomonas aeruginosa were rare. CONCLUSION: Long-term hearing aid use lowers bacterial diversity and modulates the EAC microbiome. The changes mostly affect commensals. Lowered diversity may predispose individuals to EAC conditions and needs more research.

Mycobiome of the external ear canal of healthy cows.

Malassezia yeasts belong to the normal skin microbiota of a wide range of warm-blooded animals. However, their significance in cattle is still poorly understood. In the present study, the mycobiota of the external ear canal of 20 healthy dairy Holstein cows was assessed by cytology, culture, PCR, and next-generation sequencing. The presence of Malassezia was detected in 15 cows by cytology and PCR. The metagenomic analysis revealed that Ascomycota was the predominant phylum but M. pachydermatis the main species. The Malassezia phylotype 131 was detected in low abundance. Nor M. nana nor M. equina were detected in the samples.

The mycobiota of the external ear canal of healthy cows was assessed by cytology, culture, PCR, and NGS. The presence of Malassezia was detected by cytology and PCR. Ascomycota was the main phylum and M. pachydermatis the main species. The Malassezia phylotype 131 was also detected in the samples.

[A case of trichoblastoma of the auricular cavity and review of the literature].

Trichoblastoma（TB） is a rare germ cell skin adnexal tumor of the hair, and it is a rare follicular tumor of the skin that differentiates from the hair germ epithelium and is often regarded as a benign skin tumorHowever, it is poorly confined and has a local infiltrative growth pattern. tb occurs in the head and neck region, especially in the face, and presents clinically as a slow growing, well-defined and elevated nodule. TB is routinely treated surgically. Due to the lack of universally accepted treatment guidelines or protocols, the recurrence rate after surgery is high, which makes clinical cure more difficult. In this study, a 65-year-old female patient was found to have a swelling with recurrent rupture and pus flow from the right external auditory canal opening and the auricular cavity. After initial misdiagnosis as otitis externa, she was treated with conventional anti-infective therapy, but her symptoms did not resolve and gradually worsened before coming to our hospital. The condition presented in this case is relativelyrare,therepre,timely and accurate diagnosis and treatment are crucial for prognosis improvement of such diseases.

The influence of tympanic-membrane orientation on acoustic ear-canal quantities: A finite-element analysis.

Assuming plane waves, ear-canal acoustic quantities, collectively known as wideband acoustic immittance (WAI), are frequently used in research and in the clinic to assess the conductive status of the middle ear. Secondary applications include compensating for the ear-canal acoustics when delivering stimuli to the ear and measuring otoacoustic emissions. However, the ear canal is inherently non-uniform and terminated at an oblique angle by the conical-shaped tympanic membrane (TM), thus potentially confounding the ability of WAI quantities in characterizing the middle-ear status. This paper studies the isolated possible confounding effects of TM orientation and shape on characterizing the middle ear using WAI in human ears. That is, the non-uniform geometry of the ear canal is not considered except for that resulting from the TM orientation and shape. This is achieved using finite-element models of uniform ear canals terminated by both lumped-element and finite-element middle-ear models. In addition, the effects on stimulation and reverse-transmission quantities are investigated, including the physical significance of quantities seeking to approximate the sound pressure at the TM. The results show a relatively small effect of the TM orientation on WAI quantities, except for a distinct delay above 10 kHz, further affecting some stimulation and reverse-transmission quantities.

Effects of no perforation margin trimming and EAC packing in cartilage underlay myringoplasty for chronic large perforations in children.

OBJECTIVE: Trimming of perforation margins and external auditory canal (EAC) packing are basic procedures in underlay myringoplasty for repairing chronic perforations. The objective of this study was to compare the operation time, graft outcome, hearing improvement, and complications of endoscopic cartilage underlay myringoplasty with and without trimming of perforation margins and EAC packing in children. STUDY DESIGN: Prospective, randomized study. SETTING: Tertiary referral center. MATERIAL AND METHODS: Pediatric patients older than 12 years with chronic perforations were randomly divided into two groups: myringoplasty with trimming of perforation margin and EAC packing (TPME) group or no trimming of perforation margin and EAC packing (NTPME) group. The operation time, graft success rate, hearing improvement, and complications were compared between the two groups. RESULTS: Fifty-two patients were ultimately included in the study. The mean operation time was 31.4 ± 4.2 min in the TPME group and 23.6 ± 1.7 min in the NTPME group; the difference was significant (P < 0.01). The rate of aural fullness significantly differed between the TPME and NTPME groups (P = 0.000). All participants were followed up for 12 months; the graft success rate did not significantly differ between the groups (88.5% vs. 96.2%; P = 0.603). No patients developed adhesive otitis media. Between the preoperative and postoperative measurements, the mean air-bone gap improved by 10.2 ± 2.8 dB in the TPME group and 11.6 ± 0.7 dB in the NTPME group; this was significant (P < 0.001) in both groups. CONCLUSIONS: Endoscopic cartilage underlay myringoplasty NTPME shorted the operation time and avoided aural fullness and EAC discomfort compared with the TPME technique; however, graft success and hearing improvement were comparable between the two techniques for repairing large perforations in children.

An Exploratory Study of Bimodal Electro-Aural Stimulation Through the Ear Canals for Tinnitus.

OBJECTIVE: The aim of this study was to explore the potential for bimodal auditory and noninvasive electrical stimulation at the ears to alleviate tonal, somatic tinnitus that was investigated in a small preliminary trial (11 participants). DESIGN: Auditory stimulation took the form of short "notched noise" bursts customized to each participant's tinnitus percept. Simultaneous pulsed electrical stimulation, intended to facilitate neuroplasticity, was delivered via hydrogel electrodes placed in opposite ears. RESULTS: After a 6-week intervention period, average Tinnitus Functional Index (TFI) and Tinnitus Primary Function Questionnaire (TPFQ) scores were consistent with clinically meaningful improvements in the study population. Magnitudes and effect sizes of improvements in TFI and TPFQ are comparable to those reported in other recent bimodal therapy studies using different auditory and electrical stimulation parameters. CONCLUSIONS: Our results should be considered preliminary given the small sample size, lack of crossover data, and small subject pool. When considered alongside other recent bimodal therapy results, we do believe that there are therapeutic benefits of bimodal stimulation for tinnitus sufferers that have the potential to help some with tinnitus, with a variety of stimulation parameters and electrode placements. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25444546.

Classification, registration and segmentation of ear canal impressions using convolutional neural networks.

Today, fitting bespoke hearing aids involves injecting silicone into patients' ears to produce ear canal molds. These are subsequently 3D scanned to create digital ear canal impressions. However, before digital impressions can be used they require a substantial amount of effort in manual 3D editing. In this article, we present computational methods to pre-process ear canal impressions. The aim is to create automation tools to assist the hearing aid design, manufacturing and fitting processes as well as normalizing anatomical data to assist the study of the outer ear canal's morphology. The methods include classifying the handedness of the impression into left and right ear types, orienting the geometries onto the same coordinate system sense, and removing extraneous artifacts introduced by the silicone mold. We investigate the use of convolutional neural networks for performing these semantic tasks and evaluate their accuracy using a dataset of 3000 ear canal impressions. The neural networks proved highly effective at performing these tasks with 95.8% adjusted accuracy in classification, 92.3% within 20° angular error in registration and 93.4% intersection over union in segmentation.

Epidemiology and risk factors for extension of necrotizing otitis externa.

PURPOSE: Necrotizing otitis externa (OEN) is an aggressive and morbid infection of the external acoustic meatus. What are the risk factors for OEN extension? METHODS: French monocentric retrospective study (2004-2021), including patients with OEN defined by the association of an inflamed EAM, a positive nuclear imaging, the presence of a bacteriological sample and the failure of a well-followed local and/or general antibiotic treatment. OEN was extensive if it was associated with vascular or neurological deficits, if nuclear imaging fixation and/or bone lysis extended beyond the tympanic bone. RESULTS: Our population (n = 39) was male (74%), type 2 diabetic (72%), aged 75.2 years and pseudomonas aeruginosa was found in 88% of cases. Complications for 43% of patients were extensive fixation on nuclear imaging, for 21% of them the presence of extensive bone lysis, for 13% the appearance of facial palsy, for 5.3% the presence hypoglossal nerve palsy and for 2.5% the presence of thrombophlebitis or other nerves palsies. 59% of our population had extensive OEN. The diagnosis of the extensive OEN was made 22 days later (p = 0.04). The clinical presentation was falsely reassuring due to easier identification of the tympanic membrane (70% vs 46%, p = 0.17) but associated with periauricular oedema (42% vs 0%), bone exposure (16% vs 0%) and a temporomandibular joint pain (41% vs 12%). CONCLUSION: Delayed treatment of OEN, identification of clinical bone lysis, especially when the tympanic membrane is easily visualized, and the presence of unbalanced diabetes are potential risk factors for extension of OEN.

External auditory canal reconstruction using a novel mastoidoplasty technique during canal wall down mastoidectomy: how I do it.

BACKGROUND: While mastoid obliteration techniques have received much attention in decreasing the disadvantages associated with the resultant mastoid cavity from canal wall down procedures, techniques for an anatomically normal looking ear canal reconstruction to increase the feasibility of hearing aid fitting are less commonly discussed as an alternative. METHODS: Our mastoidoplasty technique basically utilises an inferiorly based periosteal flap with or without temporalis muscles and fascia to obliterate the epitympanum and reconstruct the external auditory canal (EAC). Stay sutures are used to keep them in place. For larger cavities, demineralized bone matrix (DBM) is used to obliterate the mastoid cavity and support the neo-EAC. CONCLUSIONS: The concept of our mastoidoplasty potentially provides a very useful alternative in recreating a near normal ear canal anatomy avoiding cavity problems as well as facilitating hearing aid fitting with canal type hearing aids after canal wall down mastoidectomy.

Outcomes of Soft Versus Bony Canal Wall Reconstruction with Mastoid Obliteration.

OBJECTIVE: To compare recidivism rates, audiometric outcomes, and postoperative complication rates between soft-wall canal wall reconstruction (S-CWR) versus bony-wall CWR (B-CWR) with mastoid obliteration (MO) in patients with cholesteatoma. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary neurotologic referral center. PATIENTS: Ninety patients aged ≥18 years old who underwent CWR with MO, either S-CWR or B-CWR, for cholesteatoma with one surgeon from January 2011 to January 2022. Patients were followed postoperatively for at least 12 months with or without second-look ossiculoplasty. INTERVENTIONS: Tympanomastoidectomy with CWR (soft vs. bony material) and mastoid obliteration. MAIN OUTCOME MEASURES: Recidivism rates; conversion rate to CWD; pre- versus postoperative pure tone averages, speech reception thresholds, word recognition scores, and air-bone gaps; postoperative complication rates. RESULTS: Middle ear and mastoid cholesteatoma recidivism rates were not significantly different between B-CWR (17.3%) and S-CWR (18.4%, p = 0.71). There was no significant difference in pre- versus postoperative change in ABG (B-CWR, -2.1 dB; S-CWR, +1.6 dB; p = 0.91) nor in the proportion of postoperative ABGs <20 dB (B-CWR, 41.3%; S-CWR, 30.7%; p = 0.42) between B-CWR and S-CWR. Further, there were no significant differences in complication rates between B-CWR and S-CWR other than increased minor TM perforations/retractions in B-CWR (63% vs. 40%, p = 0.03). CONCLUSIONS: Analysis of recidivism rates, audiometric outcomes and postoperative complications between B-CWR with MO versus S-CWR with MO revealed no significant difference. Both approaches are as effective in eradicating cholesteatoma while preserving relatively normal EAC anatomy and hearing. Surgeon preference and technical skill level may guide the surgeon's choice in approach.

The variations of osseous structure of the internal acoustic canal: an anatomical study.

OBJECTIVES: The internal acoustic meatus is an osseous canal that connects the inner ear to the posterior cranial fossa. It is located in the petrous portion of the temporal bone. A thin cribriform osseous plate known as the fundus is situated at the lateral end of the canal. This study assesses the structural and numerical variations of the fundus formations. METHODS: Fifty-four temporal bones of unknown gender and age were examined with the surgical microscope. RESULTS: The temporal bones analyzed were 46.2% right-sided and 53.7% left-sided. Only one temporal bone had two parallel transverse crests, while three had a single anterior crest that split into two branches posteriorly. The number of foramina at the transverse crest varied, with 29.6% having none, 48.1% having a single foramen, and 22.2% having several foramina. An anterior crest structure was seen in 53.7% of the temporal bones, with 5% having a slightly constricted entry to the facial canal. In cases with a single nerve foramen, 48.1% had one, while 51.8% had more than one, including examples with three or four foramina. A crest was found between the foramina of the single nerve in 7% of patients. Furthermore, a crest between the saccular nerve foramen and the high fiber foramina was seen in 25.9% of cases, and 5% had two saccular nerve foramina. CONCLUSION: We think that revealing the anatomical, structural and numerical variations in the fundus will be useful in explaining the disease-symptom relationship. LEVEL OF EVIDENCE: Level 4.

Surgical Option for External Auditory Canal Cholesteatoma: A Case Report.

External Auditory Canal Cholesteatomas (EACC), is an exceptionally rare condition with a prevalence of only 0.1-0.5% among new patients1. EACC are known to possess bone eroding properties, causing a variety of complications, similar to the better-known attic cholesteatomas. We describe here the novel surgical management of a case of EACC. She is 38-year-old female who presented with otorrhea for 6 months. Clinical examination and radiological investigations suggested the diagnosis of an external auditory canal cholesteatoma. The patient underwent modified radical mastoidectomy with type 1 tympanoplasty with meatoplasty. Post-operatively, the patient showed marked clinical improvement.

Perspective on Temporomandibular Joint Disorder: Foramen Tympanicum Defect.

BACKGROUND: Foramen tympanicum (FT) is a defect located anterior-inferior to the external acoustic meatus. We evaluated its prevalence, location, size, and relationship with temporomandibular joint (TMJ) disorders. METHODS: Cone beam computed tomography was performed for 200 patients who presented to the Karamanoglu Mehmetbey University Ahmet Kelesoglu Faculty of Dentistry Hospital. The location and size of the FT in the axial and sagittal planes were evaluated. Descriptive statistics were used to compare the study parameters among age and sex groups. Patients with FT were reevaluated by two maxillofacial surgeons at the study centre. RESULTS: In total, 200 images from 400 joints were examined. Unilateral and bilateral FT (19 [9.5%] and 8 [4%], respectively) was detected in 35 (17.5%) images from 27 (13.5%) patients. Examinations were performed for TMJ disorders in 24 patients. Participants with bilateral defects had the highest rates of presence of sounds and ear pain on the left and right sides (p < .05). CONCLUSION: Foramen tympanicum can lead to TMJ disorders and spread of tumours or infections from the external auditory canal to the infratemporal fossa. The increased prevalence of such disorders in patients with bilateral FT suggests an association between them.

Variant Types of Preauricular Sinuses: Classifications, Clinical Presentation and Management.

OBJECTIVE: To make surgeons aware of the differing types of preauricular sinuses (PAS), we summarize our experience with diagnosis and treatment of varying types of PAS. METHODS: We retrospectively reviewed clinical data from patients who had undergone preauricular fistulectomy between March 2015 and March 2020. These patients were categorized into two groups according to locations of congenital fistula pit. RESULTS: Twelve patients with variant PAS accounted for 6.8% (12/177) of all patients. The variant types of PAS could be classified into three types (from type 1 to type 3), based on the location of the fistula pit. Type 1 (seven patients; eight ears) patients had pits located on the ascending helix crus, whereas type 2 (four patients, four ears) and type 3 (one patient, one ear) patients had pits located on the external auditory canal (EAC) and lobule, respectively. Fistular tracts penetrated the cartilage of the helix crus in seven of the type 1 variant ears. Swelling and discharge were located at the ascending helix crus (in four ears), cavum concha (in two ears), and posterior to the auricle (in one ear). In four of the type 2 ears, the fistular tracts were located at the anterior margin of the ascending limb of the helix. CONCLUSION: Fistula tracts where fistula pit occurred on the ascending helix crus were more likely to penetrates through the cartilage, and fistula tracts with fistula pits that occurred on the EAC were adjacent to the cartilage of the ascending helix and tragus. Meticulous dissection and complete removal of fistula tissue are critical to avoid postoperative recurrence. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:3839-3845, 2024.

Expression of EGFR and p16 in Squamous Cell Carcinoma of External Auditory Canal.

The expression of EGFR and p16 in the external auditory canal squamous cell carcinoma (EACSCC) and their impacts on oncological outcomes were not well studied. Seventeen-one consecutive patients who were treated for EACSCC at Kobe University Hospital from 1995 to 2018 were enrolled in this study. The expression of EGFR, and p16 were evaluated and their impacts on oncological outcomes were statistically analyzed. Positive expression of EGFR was observed in 62 patients (87%). Strong positive expression of p16 were observed in 18 patients (32.4%), and weakly positive expression in 30 patients (42.3%), respectively. While the number of the patients with negative EGFR expression were limited, all the surgically treated patients with negative EGFR expression have been alive without disease. In the patients with T3 & T4a EACSCC, prognosis of the patients with positive p16 expression EACSCC tended to be better than those with negative p16 expression. These results suggest the clinical significance of EGFR and p16 expressions in the patients with advanced EACSCC to predict oncological outcomes.

Thermal variation in human temporal bone using rigid endoscope.

OBJECTIVE: Compare thermal variation in the region of the External Acoustic Canal (EAC) and the Round Window (RW) using different rigid endoscopes and light sources in human temporal bones. METHOD: This is an analytical experimental study using human temporal bones. Thermal variation was assessed during ten minutes, using a thermometer in the region of the EAC and the RW of two temporal bones, right and left. We used three different endoscopes (0° 4-mm, 0° 3-mm and 30° 4-mm) and five intensity/type light source (Halogen 100%, LED 50%, LED 100%, Xenon 50% and Xenon 100% with the same endoscope light fiber. RESULTS: We found temperature elevations in the EAC and RW in all measurements. Larger caliber endoscopes (4-mm) and light sources at 100% intensity generated higher temperatures, slightly higher in halogen and xenon. The 30° endoscopes tended to put more heat on structures, with little difference in most measurements. We identified greater temperature variations in the EAC of the right and left temporal bones compared to the RW overall. The highest temperature acquired in the present study was in the EAC of the temporal bone with a 4-mm and 30° endoscope, using xenon light source (intensity of 100%), with an increase of 4.51 °C. CONCLUSION: The type of endoscope and light source can influence the thermal variation and the risk of tissue injury during endoscopic ear surgery. Larger endoscopes with xenon and halogen light sources at maximum intensity generate more heat.