Syringocystadenoma Papilliferum in the External Ear Canal

Out of all benign tumors of the ceruminous glands, syringocystadenoma papilliferum is the rarest and represents only 2% of cases. It is an extremely rare benign tumor that originates from modified apocrine sweat glands. The aim of this paper was to present, according to our findings, the 18th case of syringocystadenoma papilliferum in the external auditory canal, with a detailed review of its clinical, radiological and histomorphological characteristics. A 59-year-old man reported to our clinic due to a 5×5 mm papillomatous growth at the entrance to the right external auditory canal. Histopathology indicated, after an excisional biopsy, that it was a syringocystadenoma papilliferum. The resection lines were free of tumor tissue, and the patient has no signs of tumor recurrence. Although rare, it should be considered as a differential diagnosis of lesions in this region. Complete excision is mandatory in order to avoid recurrence and potential malignant alteration.

Removal of external auditory canal foreign bodies in the pediatric emergency department - A retrospective comparison study

INTRODUCTION

The removal of foreign bodies from the external auditory canal (EAC) is a common cause of referral to the pediatric emergency department (PED). The attempt at removal of foreign bodies can lead to complications ranging from mild canal injuries and through severe inner ear damage. The removal requires knowledge and expertise. Ear, Nose and Throat (ENT) physicians are considered the most qualified to remove these foreign bodies. The decision of when the ENTs need to be involved is debated.

METHODS

A retrospective analytical comparison study was conducted. The study included all children admitted to the PED for EAC foreign body removal, between the years 2009-2019.

RESULTS

A total of 333 children were included in the study. The mean age was 6.53 years. Success rate of the procedure on the first attempt performed by pediatricians was 82.4% and when performed by ENT physicians the success rate was 96.1%. However, when those with a previous attempt of removal were removed from the study the success rates of PED physicians were 93.9% and of ENT physicians were 96.8%.

CONCLUSION

This single center study shows that with correct case evaluation, the PED physician can and should succeed in EAC FB removal with minimal complications and comparable to ENT performance. If a first attempt failed, an ENT consult is warranted.

Determining the existence of the foramen of Huschke in patients with temporomandibular joint disorders using cone beam computed tomography: retrospective cohort study

Background

Foramen of Huschke has been presented as an unusual developmental defect in anteroinferior aspect of external auditory canal. It can be associated with significant otologic complications. The purpose of this study was to determine the association between existence of foramen of Huschke and temporomandibular joint disorders in Cone Beam Computed Tomography (CBCT) images.

Methods

Of an initial sample of 465 patients, we retrospectively evaluated the CBCT images of 118 individuals with clinical signs and symptoms of temporomandibular joint disorders as case group and 256 individuals as control group. The presence, size and localization of foramen of Huschke were assessed in the axial and corrected sagittal images. The sex and age distribution were determined. Fisher’s exact test, T-test and Pearson’s Chi-square were applied to assess the relationship between foramen of Huschke and temporomandibular joint disorders in the case and control groups considering age and sex.

Results

The foramen of Huschke prevalence was slightly higher in patients with temporomandibular joint disorders (3.4%) than patients without temporomandibular joint disorders (0.8%). However, the difference was not statistically significant (P = 0.082). foramen of Huschke was found in five females and one male. There was no significant difference between case and control groups considering the age of patients with foramen of Huschke (P = 0.683). There was no significant difference between the case and control groups, considering the right and left ears in distribution of foramen of Huschke (P = 0.099) (P = 0.183).

Conclusions

Higher prevalence of foramen of Huschke in patients with temporomandibular joint disorders may suggest possible mechanism for temporomandibular joint disorders development that can be affected by presence of foramen of Huschke.

Metastasis of parotid adenocarcinoma to the external auditory canal

Metastatic carcinoma of the external auditory canal (EAC) is extremely rare. Herein, we report the first case of a patient with metastasis of parotid adenocarcinoma to the EAC. Clinicians should include it in the differential diagnosis of tumors of the EAC. In patients with parotid carcinoma, a physical examination of the entire head and neck, including the EAC, should be performed before surgery.

Treatment Strategies for Malignancies of the External Auditory Canal

Malignant tumors of the external auditory canal (EAC) are rare tumors in the head and neck. Delayed diagnosis is not uncommon because the symptoms of early tumors are nonspecific. Various surgical and oncological treatment modalities have been reported. Decision-making depends on pathological feature and stage of the lesions, patient’s general condition and preference, and physician’s experience and skill. Radical surgery is widely accepted as the primary treatment of choice. Postoperative radiotherapy is used more often to improve local and regional control of the disease. Chemotherapy is usually recommended for advanced disease, residual disease, and metastasis. Prognosis is affected by multiple factors such as TNM stage, surgical margin, pathological type and differentiation of tumor, involvement of facial nerve, and so on. Although the survival rate is improved significantly over the past several decades with the development of skull base surgery, neuroradiology, anesthesiology, and oncology, it remains challenging to diagnose and treat EAC malignancies due to the rarity, the local anatomical complexity of temporal bone, and the lack of standard TNM staging system.

Isolation, culture, and identification of ceruminous gland cells

External auditory canal (EAC) stenosis or atresia usually requires a skin graft to repair, but due to the lack of a graft containing functional glands, postoperative complications such as infection and eczema are common. The aim of this study was to isolate and characterize seed cells for the construction of tissue engineered EAC skin containing ceruminous gland by isolating and cultivating cells of ceruminous gland. In this study, EAC skin samples were harvested from adult goats for ceruminous gland cell isolation. Cell morphology and proliferation rates, expression of CK7, CK8, CK18, and CK19 (glandular cell specific-markers), and secretion of β-defensin-1, lysozyme, and polysaccharides were evaluated at different passages to verify the presence of ceruminous gland cells and determine whether function and proliferation potential were maintained. Ceruminous glands were successfully isolated and extracted from goat EAC skin. Furthermore, the isolated glandular cells maintained robust proliferation potential, exhibited high expression of CK7, CK8, CK18, and CK19, and vigorously secreted β-defensin-1, lysozyme, and polysaccharides in this culture system. However, expression of glandular cell specific-markers and secretory function gradually declined with increasing passage number, indicating dedifferentiation of the subcultured ceruminous gland cells after five passages. In conclusion, ceruminous glands were successfully isolated, cultured, and expanded from goat EAC skin using the serumcontaining culture system. Importantly, the isolated glandular cells retained robust proliferation potential and maintained their phenotype and function in early passages (P1-P3), indicating the method's potential application for ceruminous gland regeneration.

Capillary Hemangioma as an Unexpected Pathology in the External Auditory Canal

INTRODUCTION

Hemangiomas are benign vascular lesions frequently observed in infancy and childhood.

CASE REPORT

A 14-year-old boy was referred to the hospital with a left-sided ear canal mass and hearing impairment. Otoscopic examination revealed a mass that occluded the canal. The transcanal surgical excision was performed. The mass was dissected from the skin, no bony erosion was noted intraoperatively, and the skin was returned back properly. The histopathological report demonstrated a capillary hemangioma of the external auditory canal.

CONCLUSIONS

Hemangiomas are relatively common in the head and neck, but rarely detected in the external ear canal and tympanic membrane. Hemangioma of the ear canal may be asymptomatic and accidentally observed. Despite the rarity of the mass, it is important to consider them in the differential diagnosis of external auditory canal masses. The computed tomography and magnetic resonance imaging with gadolinium help to reveal the vascular nature of the mass. Complete surgical excision is the treatment of choice.

Pleomorphic adenoma in the external auditory canal: Arising at an atypical location

Pleomorphic adenoma is a common, benign neoplasm typically located in the major salivary glands. The external auditory canal is an atypical location for a pleomorphic adenoma to originate. Wide surgical excision is essential in cases of pleomorphic adenoma due to its tendency to recur and change into malignancy. We report a case of pleomorphic adenoma emerging in the external auditory canal, which is an atypical location for it to originate. A 23-year-old male presented with swelling and decreased hearing in the left ear for 2 months. On examination, there was a smooth, pink, firm swelling in the cartilaginous part of external auditory canal. Pure tone audiogram and computed tomography of temporal bone were performed. The patient underwent excision biopsy and the diagnosis of pleomorphic adenoma was confirmed after histopathology. Long-term follow-up is recommended as pleomorphic adenoma has the potentiality to recur or transform into malignancy.

Associations between condylar fractures and external auditory canal fracture: A 7-year retrospective study

The study aimed to investigate whether the incidence rate of external auditory canal (EAC) fracture varies among different clinical types of condylar fracture. A retrospective cohort study was conducted in single hospital of China. Eligible patients diagnosed with mandibular condylar fractures were retrospectively reviewed. Among all patients with condylar fractures (318 cases and 437 sides), 45 cases and 59 sides (59/437 sides, 13.5%) were found with EAC fracture, including 17(17/38, 44.7%) sides of sagittal fracture of condyle (Type I), 21(21/59, 35.6%) sides of intracapsular condylar fracture (Type II), 8 (8/306, 2.6%) sides of condylar neck fracture (Type III), and 6 (6/34, 17.7%) sides of condylar base fracture (Type IV). Type III condylar fracture had a significant lower rate of EAC fracture than all other three types (all p<0.001). Type I condylar fracture had a higher rate of EAC fracture compared to Type IV (p=0.014). The incidence rates of EAC fracture in combined Type I+Type II group (38/97, 39.2%) was significantly higher than Type III (8/306,2.6%, p<0.001) and Type IV (6/34,17.7%, p=0.002). A total of 35 sides (27 patients) with combined fractures were followed up for 6 months after treatment, among whom 11 sides (7 patients) were operated for both fractures simultaneously. Neither EAC stenosis nor hearing loss was observed. Meanwhile, for 24 non-operated ears from 20 patients, all EACs showed different degrees of stenosis. In conclusion, oral and maxillofacial surgeons should pay more attention to EAC fracture combined with condylar fracture, especially for patients diagnosed with condylar head fracture. Maxillofacial fractures should be accompanied by early treatment of EAC fractures, in order to prevent EAC stenosis, hearing loss, and other complications.

Piezoelectric canalplasty for exostoses and osteoma

OBJECTIVE

To evaluate the safety profile and surgical technique for removal of symptomatic exostoses and osteoma of the external auditory canal with a micro-oscillating piezoelectric device.

METHOD

A chart review was conducted on patients undergoing piezoelectric canalplasty between 2019 and 2021 at tertiary referral hospital. Surgery was performed by two surgeons with varying experience. Bone removal was achieved using both osteotomy and osteoplasty. Postoperative complications, operative time and hearing outcome were evaluated.

RESULTS

The study comprised 16 patients (16 ears). No major complications occurred. The skin of the auditory canal was completely preserved in all patients without injury to the tympanic membrane. Except for one patient with known noise-induced hearing loss, there was no postoperative deterioration of the bone-conduction threshold more than 10 dB HL at any frequency. The difference of the bone-conduction threshold in pure-tone audiometry (average for 0.5, 1, 2 and 4 kHz) three weeks postoperatively had a median of 0.6 dB ± 5.7. One patient complained of temporary new tinnitus. One patient had prolonged wound healing. Mean operative time was comparable with literature data.

CONCLUSION

The atraumatic characteristics of the piezoelectric instrument enable low-risk removal of external auditory canal exostoses and osteoma. Through the combination of precise osteotomy and osteoplasty, this novel instrument has the potential to become established in routine canalplasty.

Reconstruction of the external auditory canal: The tragal flap revisited and review of contemporary reconstructive techniques

BACKGROUND

Primary malignancies arising in the external auditory canal (EAC) are rare and usually are treated surgically. We review techniques to reconstruct the EAC following ablative surgery, and introduce a rarely utilized tragal skin flap which has particular advantages for reconstruction of limited anterior EAC defects.

METHODS

The terms "tragal flap", "external auditory canal", "preauricular tragal flap", "reconstructive techniques" were searched on PubMed and Google Scholar.

RESULTS

Our review identified one description of a tragal flap to reconstruct the EAC following resection of a malignancy. We add an additional case of a preauricular tragal flap to reconstruct the anterior EAC following resection of a recurrent basal cell carcinoma located in the EAC that led to a circumferential defect.

CONCLUSION

There are several surgical techniques that can be utilized to reconstruct the EAC. We describe a novel tragal flap used to reconstruct the anterior EAC following resection of a recurrent tumor.

The outcome and complication of endoscopic removal of pediatric ear foreign body

OBJECTIVE

To evaluate the outcome and complications of endoscopic removal of pediatric ear foreign bodies (FBs).

METHODS

This study was a retrospective chart review of pediatric and adult patients who presented for ear FB removal over a 5-year period.

RESULTS

In 191 children with ear FBs, 105 (55.0%) of the FBs were in contact with or close to the tympanic membrane (TM). The FB was removed using direct suction with a sucker in 172 (90.1%), a right-angle hook alone in 13 (6.8%), and alligator forceps alone in 6 (3.1%). In total, 34 (17.8%, 34/191) complications were reported; they included complications from the FB itself in 2 (5.9%), from prior attempts at removal by non-specialist otologists in 29 (85.3%), and from attempts by the authors in 3 (8.8%). The complication rate for non-specialist otologists using headlights was significantly higher than that for specialist otologists using endoscopes (29/82, 35.4% vs 3/109, 2.8%, P < 0.001).

CONCLUSIONS

Most pediatric ear FBs are small and in contact with the TM. The use of an endoscope to assist with foreign body removal may be both safe and effective for pediatric ear FBs.

Management of Ear Trauma

Facial trauma remains a common reason for visits to the emergency department or urgent care facility. The ear remains susceptible to trauma given its delicate anatomy and position in the maxillofacial region. Understanding the anatomy and recognizing the circumstances regarding the mechanism of injury help dictate treatment. The goals of treatment should remain to restore the physiologic form and function of the ear. Middle ear injuries should also be addressed during the process. Although primary repair remains feasible in most cases, there are instances when delayed and staged reconstruction is necessary to achieve successful results.

Primary external auditory canal cholesteatoma of 301 ears: a single-center study

PURPOSE

Limited literature exists on primary external auditory canal (EAC) cholesteatoma (EACC). Here, we focus on the clinical features of this rare disease, especially the invasive patterns of lesion progression, through a large population study and present simple and practical staging.

METHODS

In all, 276 patients (male 99; female 177; mean age 41.3 ± 21 years; ears 301) with primary EACC were retrospectively analyzed. Stage I indicated EACC without bony lesions, stage II indicated invasion confined within EAC, stage III indicated invasion beyond the EAC involving mastoid air cells or tympanic cavity, but within the temporal bone, and stage IV indicated invasion beyond the temporal bone.

RESULTS

In all, 41, 219, 40, and 1 ear with Stage I, II, III, and IV lesions were found, respectively. Common clinical symptoms were hearing loss (237 ears, 78.7%), otalgia (221 ears, 73.4%), and otorrhea (85 ears, 28.2%). The mean air conduction and air-bone gaps were 45.4 ± 17.9 dB HL and 24.6 ± 15 dB HL, respectively. EACCs were found to invade in all directions of the EAC, with the inferior wall (224 ears, 74.4%) > posterior wall (207 ears, 68.8%) > anterior wall (186 ears, 61.8%) > superior wall (86 ears, 28.6%) invasion; multiwall invasions (207 ears) were common; however, inward invasions into the tympanic cavity were rare.

CONCLUSION

Primary EACCs occurred mostly in women and often unilaterally invaded multiple bony walls in the lower half of the EAC. The present staging reflects the patterns and severity of lesion progression and may be beneficial in treatment planning.

A Recurrent Variant in POLR1B, c.3007C>T; p.Arg1003Cys, Associated with Atresia of the External Canal and Microtia in Treacher Collins Syndrome Type 4

Treacher Collins syndrome (TCS) is a heterogenous malformation syndrome characterized by a distinct facial appearance including downslanting palpebral fissures, malar hypoplasia, conductive hearing loss, and mandibular hypoplasia. Recently, a new causative gene, POLR1B, encoding DNA-directed RNA polymerase I subunit RPA2, was identified as a fourth type of TCS (TCS4). We describe another patient with TCS4 caused by a recurrent POLR1B variant, c.3007C>T; p.Arg1003Cys. Including our patient, all 4 patients with p.(Arg1003Cys) had atresia of the external auditory canal and microtia. All of the reported pathogenic variants in POLR1B were clustered at only 2 residues. Our patient highlights the genotype-phenotype correlation in TCS4 associated with POLR1B.

The MO-meatocanalplasty: long-term results in the narrow external auditory canal with recurrent otitis externa or the inability to wear a hearing aid

OBJECTIVE

The MO-meatocanalplasty is the oblique modification of the M-meatoplasty. The MO-meatocanalplasty was designed to address the superior quadrants of the meatus and the bony canal without the need for a retro-auricular incision. This retrospective analysis was performed to evaluate the long-term results of the MO-meatocanalplasty in patients with a narrow external auditory canal (EAC) with recurrent otitis externa or in patients unable to wear a hearing aid.

METHODS

Twenty-two ears in twenty consecutive patients who received a MO-meatocanalplasty for a narrow EAC with recurrent otitis externa or the inability to wear a hearing aid were analysed retrospectively. There were no patients included with any type of previous or planned second stage tympanoplasty procedures. A follow-up period of 3 years was analysed for postoperative recurrent narrowing, the self-cleaning capacity of the EAC, the recurrence of otitis externa, the inability to wear a hearing aid, change in hearing level and for all types of aesthetical complaints.

RESULTS

The MO-meatocanalplasty procedure was effective in 82% (n = 18). Postoperative recurrent narrowing was detected in 9% (n = 2). Insufficient self-cleaning capacity of the EAC was 9.1% (n = 2). The ability to wear a hearing aid was restored in all patients with the need for a hearing aid. No aesthetical complaints were reported.

CONCLUSION

The MO-meatocanalplasty is an effective, safe and aesthetical accepted procedure to address the narrow meatus and external auditory canal. With this procedure, there is no need for a retro-auricular incision in order to create a well aerated, dry and self-cleaning EAC in patients with a narrow EAC with recurrent otitis externa or in patient with the inability to wear a hearing aid.

Impact of ear protection on occurrence of exostosis in surfers: an observational prospective study of 242 ears

PURPOSE

The aim of the study was to investigate the efficacy of ear protection (earplug and surf hood) in preventing the development of external auditory exostosis (EAE) in surfers.

METHODS

We performed a prospective observational study. Volunteer surfers were recruited from June 2016 to October 2017 on the Brittany coast in France. Each participant filled in a questionnaire and underwent otoscopic digitalized photography to establish the degree of external ear obstruction by two different practitioners. The correlation between the percentage of external ear obstruction and the time spent in water with or without protection was evaluated. Risk factors of EAE were assessed.

RESULTS

Two hundred and forty-two ears were analysed. The incidence of EAE was 89.96% with an average rate of obstruction of 37.65%. Risk factors for EAE were male sex (p = 0.0005), number of years practicing surf (p < 0.0001) and symptoms of ear obstruction (p = 0.0358). A significant correlation was found between EAE severity and number of hours spent in water without any protection (earplugs or surf hood) (p < 0.0001). No correlation was found between EAE severity and time spent in water with earplugs (p = 0.6711) but a correlation was identified between obstruction and time spent in water with surf hood (p = 0.0358).

CONCLUSIONS

Wearing earplugs is an effective way to prevent EAE in surfers unlike surf hood.

Comparison of fetal and adult tympanic membrane sizes: a cadaveric study

OBJECTIVE

The work aimed to compare fetal and adult tympanic membrane (TM) sizes for understanding dimensional development from intrauterine life to adulthood.

METHODS

Fifty-six temporal bones (18 fetuses, 10 elderly adults, half male and half female in each group) were included in this study. Using a digital image software, the TM height, width and area were measured.

RESULTS

The mean area, height and width of the TM in adults were found as 58.84 ± 22.01 mm2, 9.06 ± 1.33 mm, and 8.10 ± 1.43 mm, respectively. Moreover, the mean area, height and width of the TM in fetuses were measured as 47.62 ± 12.57 mm2, 8.22 ± 1.12 mm, and 7.25 ± 1.15 mm, respectively. The TM dimensions were increasing in fetuses between 20-32 weeks of gestation. However, the TM dimension was statistically similar at the 7th month, the 8th month and adult periods. The TM height was greater than its width in fetuses and adults.

CONCLUSION

The calculated regression equations of the TM parameters in fetuses may be used to estimate its size. The TM size did not change from the 7th gestational month, and thus the membrane reached adult diameter in fetal life. The TM height and width showed a very wide range; therefore, we thought that the 12 mm (the height) × 10 mm (the width) graft might be ideal dimension during the repair of the TM perforations.

Epithelioid Sarcoma of the External Auditory Canal: An Uncommon Tumor at an Unusual Site and a Brief Overview of the Literature

We present a case (41 years old pregnant female) with epithelioid sarcoma arising in the left external auditory canal. On immunohistochemistry, the tumor cell diffusely expressed cytokeratins and showed patchy expression of ERG and CD34. The neoplastic cells demonstrated uniform loss of INI1-expression. Epithelioid sarcoma arising in the external auditory canal is rare. Awareness that ES may rarely arise at unusual sites is of critical importance in order to apply a broad enough panel in the immunohistochemical study, so a misdiagnosis of carcinoma can be avoided.

Indications for and extent of elective neck dissection for lymph node metastasis from external auditory canal carcinoma

OBJECTIVES

We aim to clarify the frequency of lymph node metastasis of external auditory canal (EAC) carcinoma, including susceptible locations, adequate extent of elective neck dissection, and the relationship between the tumor infiltration site and lymph node metastasis.

PATIENTS AND METHODS

From 2003 to 2018, 63 patients with EAC carcinoma at Tokyo Medical and Dental University Hospital were enrolled in this study. The T and N stages, locations of clinically positive lymph nodes, prognoses, and anatomic site of tumor infiltration were analyzed after treatment.

RESULTS

Clinically positive lymph node metastasis (cN+) was detected in 18 patients (28.6%), consisting of T1, T2, T3, and T4 disease in 1 (6%), 2 (22%), 8 (38%), and 7 (41%) patients, respectively. The metastatic locations were at level II in 10 patients, parotid gland nodes in 7, preauricular nodes in 5, level Ib in 3, level Va in 3, level III in 1, and superficial cervical nodes in 1. Neck recurrence was determined in two of 45 patients with clinically negative lymph nodes (cN0), with the metastatic locations being levels II, Ib, and III. Among 18 cN+ cases, neck recurrence was noted in 2 of 9 patients who underwent neck dissection. Neck lesions were found to be manageable in all five patients who underwent docetaxel, cisplatin, 5-fluorouracil, and radiation therapy (TPF-RT). No relationship was noted between the tumor infiltration site and lymph node metastasis among T3/4 canrcinoma patients.

CONCLUSIONS

Elective neck dissection could be indicated only in T3/4 patients with free flap reconstruction. Levels Ib to III are considered appropriate for elective neck dissection in cN0 cases. Levels Ib to III and Va indicated favorable sites, even in cases with metastasis in the parotid gland or preauricular area. Furthermore, TPF-RT could be a useful option even in cN+ cases.

[Acute promyelocytic leukemia recurrence diagnosed due to granulocytic sarcoma of the external auditory canal]

A 47-year-old man was diagnosed with acute promyelocytic leukemia (APL) accompanied by pancytopenia and left forearm swelling. Complete remission was achieved with remission induction therapy using all-trans retinoic acid (ATRA), and consolidation therapy was completed. Three months after the treatment, left ear closure was observed, and a mass lesion was found in the left external auditory canal. An initial tumor biopsy only revealed inflammatory cell infiltration. Moreover, the tumor's rebiopsy performed 3 months later revealed MPO-positive and CD68-positive granulocyte infiltration. Furthermore, the rebiopsy revealed 4.9×10⁵ copies/µgRNA of PML/RARα, the patient was diagnosed with locally recurrent APL. A bone marrow examination 2 weeks later confirmed an increase in myeloblasts and promyelocytes for the first time since the confirmation of remission. Therefore, it was diagnosed as bone marrow recurrence. Reinduction therapy using ATRA and arsenic trioxide again led to complete remission, after which autologous peripheral blood stem cell transplantation was performed. Currently, complete remission is being maintained. In this case, the recurrence of the external auditory canal lesion preceded the bone marrow recurrence. Therefore, it is important to note the nonspecific leukemia recurrence patterns of the external auditory canal.

Incipient Warthin tumor of intraparotid lymph node in a patient with squamous cell carcinoma of the external auditory canal: An incidental finding

The occurrence of intranodal salivary gland neoplasm is uncommon; squamous cell carcinoma (SCC) of the external auditory canal (EAC) is another rare occurrence. Clinically, SCC of EAC presents with symptoms similar to other benign otologic conditions. A case of Stage I SCC in EAC region is presented here in a 60-year-old male patient with incidental intranodal Warthin tumor along with the histological differential diagnosis. The patient is being followed up. There is no evidence of recurrence 1 year and 11 months after surgery.

Measurement method for external auditory canal and clinical application in congenital aural stenosis

OBJECTIVE

To describe a measurement method for external auditory canal (EAC), especially in congenital aural stenosis (CAS).

METHODS

High-resolution CT (HRCT) datasets of CAS were imported into the MIMICS 15.0 software for image processing. We used two methods to evaluate the degree of CAS. One is sagittal reconstruction measurement method, the minor axis of the bony ear canal was measured in each layer using sagittal reconstruction. The other is Matlab procedure calculation, we calculated the midpoint axis values of the EAC in each Frankfurt plane. Finally, we compared the minimum value of each method, and verified the sagittal reconstruction measurement method retrospectively in the CAS cases without cholesteatoma who had undergone meatoplasty.

RESULTS

Twenty CAS cases were selected using the sagittal reconstruction measurement method and Matlab procedure calculation to evaluate the degree of CAS. The mean age was 9.55 ± 2.85 years old (range: 6-15). The mean degree of CAS was 2.09 ± 0.50 mm by sagittal reconstruction measurement method and 2.03 ± 0.58 mm by Matlab procedure calculation. There were no significant differences in the two groups (t = -1.371, p = 0.186). A total of 94 HRCT datasets were imported into MIMICS for verification. The mean age was 11.66 ± 6.56 years old (range: 6-39). Mean stenosis of EAC at surgery was 2.88 ± 0.93 mm (range: 1-4) by using sagittal reconstruction measurement method.

CONCLUSIONS

Matlab procedure calculation is precise but relatively complicated and is only for scientific research. The sagittal reconstruction measurement method to calculate the most stenotic part of the bony ear canal is relatively simple and accurate to evaluate the degree of CAS. In cases of CAS without cholesteatoma, the precise measurement was critical for the next consultation.

Prevalence of foramen Huschke: evaluation of the association between mastoid pneumatization volume and the existence of foramen Huschke using cone beam computed tomography

PURPOSE

The study examined the association between mastoid pneumatization (MP) volume and the existence of foramen Huschke (FH).

METHODS

Cone beam computed tomography (CBCT) images of 1117 patients (2234 mastoid regions) were analyzed. The prevalence of FH was calculated. The association of MP volume calculated in 83 patients (48 women, 35 men) with sex, side, and the existence of FH analyzed. T test and Pearson's Chi-square test were used for statistical analyses.

RESULTS

FH was observed in 223 (20%) patients. FH was unilateral in 141 (63.7%) patients (74 left-sided, 68 right-sided) and bilateral in 81 (36.3%) patients. Six patients with FH had herniation into the external auditory canal. MP volume was significantly greater in females (p = 0.016). Additionally, MP volume was significantly greater in patients having FH (p = 0.009).

CONCLUSION

It is possible to speculate that the volume of MP, which is in close neighborhood with the external auditory canal, somehow affects the existence of FH located in the tympanic segment.

Denosumab-induced osteonecrosis of external auditory canal

Denosumab is the world's first human monoclonal antibody for the treatment of osteoporosis and shares an active pathway with bisphosphonates, strongly suppressing osteoclast activities. This is the first case report describing a possible relationship between the development of osteonecrosis of external auditory canal and denosumab administration. We herein report an 81-year-old woman diagnosed with left osteonecrosis of external auditory canal who had a history of denosumab administration. She underwent left radical mastoidectomy due to being refractory to conservative treatment. No major complications or recurrence were observed in the left ear after surgery, but bone erosion in the right ear has continued to progress slowly despite the cessation of denosumab administration. Otolaryngologists should be aware of the association between osteonecrosis of external auditory canal and denosumab administration and consider performing long-term observation even after cessation.