Predicting residual cholesteatoma with the Potsic staging system still lacks evidence: a systematic review and meta-analysis.

PURPOSE: To investigate the rate of residual disease in the Potsic staging system for congenital cholesteatomas. METHODS: A protocol registration was published on PROSPERO (CRD42022383932), describing residual disease as a primary outcome and hearing improvement as secondary. A systematic search was performed in four databases (PubMed, Embase, Cochrane Library, Web of Science) on December 14, 2022. Articles were included if cholesteatomas were staged according to the Potsic system and follow-up duration was documented. Risk of bias was evaluated using the Quality In Prognosis Studies (QUIPS) tool. In the statistical synthesis a random effects model was used. Between-study heterogeneity was assessed using I2. RESULTS: Thirteen articles were found to be eligible for systematic review and seven were included in the meta-analysis section. All records were retrospective cohort studies with high risk of bias. Regarding the proportions of residual disease, analysis using the χ2 test showed no statistically significant difference between Potsic stages after a follow-up of minimum one year (stage I 0.06 (confidence interval (CI) 0.01-0.33); stage II 0.20 (CI 0.09-0.38); stage III 0.06 (CI 0.00-0.61); stage IV: 0.17 (CI 0.01-0.81)). Postoperative and preoperative hearing outcomes could not be analyzed due to varied reporting. Results on cholesteatoma location and mean age at staging were consistent with those previously published. CONCLUSION: No statistically significant difference was found in the proportions of residual disease between Potsic stages, thus the staging system's applicability for outcome prediction could not be proven based on the available data. Targeted studies are needed for a higher level of evidence.

Evaluation of Eustachian tube dimensions by temporal bone computed tomography in patients with chronic otitis media.

OBJECTIVE: To clarify the relationship between Eustachian tube dimensions and chronic otitis media aetiology using temporal bone computed tomography. METHODS: The data of 231 adults who had undergone surgery for unilateral chronic otitis media were reviewed retrospectively. Diseased and healthy ears were enrolled in groups 1 and 2, respectively. Group 1A included chronic otitis media with cholesteatoma (n = 28) and group 1B included chronic otitis media without cholesteatoma (n = 203). The Eustachian tube dimensions of groups 1 and 2 were compared, to clarify the relationship between the Eustachian tube dimensions and chronic otitis media aetiology. Groups 1A and 1B were compared to assess the effect of Eustachian tube dimensions on cholesteatoma development. RESULTS: The Eustachian tube was shorter, narrower and located more horizontally in ears with chronic otitis media. No significant difference was found between groups 1A and 1B. CONCLUSION: Eustachian tube dimensions are closely related to chronic otitis media aetiopathology, but are not related to cholesteatoma development.

Single-cell transcriptomics of human cholesteatoma identifies an activin A-producing osteoclastogenic fibroblast subset inducing bone destruction.

Cholesteatoma, which potentially results from tympanic membrane retraction, is characterized by intractable local bone erosion and subsequent hearing loss and brain abscess formation. However, the pathophysiological mechanisms underlying bone destruction remain elusive. Here, we performed a single-cell RNA sequencing analysis on human cholesteatoma samples and identify a pathogenic fibroblast subset characterized by abundant expression of inhibin ßA. We demonstrate that activin A, a homodimer of inhibin ßA, promotes osteoclast differentiation. Furthermore, the deletion of inhibin ßA /activin A in these fibroblasts results in decreased osteoclast differentiation in a murine model of cholesteatoma. Moreover, follistatin, an antagonist of activin A, reduces osteoclastogenesis and resultant bone erosion in cholesteatoma. Collectively, these findings indicate that unique activin A-producing fibroblasts present in human cholesteatoma tissues are accountable for bone destruction via the induction of local osteoclastogenesis, suggesting a potential therapeutic target.

Higher degree of keratinization correlated with severe bone destruction in acquired Cholesteatoma.

BACKGROUND: Acquired cholesteatoma is characterized by hyper-keratinized squamous epithelium and bone destruction. However, direct evidence for hyper-keratinized epidermis promoting bone destruction is lacking. AIMS/OBJECTIVES: To determine whether higher degree of keratinization correlated with severe bone destruction and further offer direct evidence for keratinocyte-inducing osteoclastogenesis. MATERIALS AND METHODS: Histological changes and clinical relevance were analyzed in human-acquired cholesteatoma. Animal models were established by implanting autologous epidermis with different degrees of keratinization. The severity of bone resorption and the number of osteoclasts were compared in different keratinized groups. An in vitro coculture system was developed to mimic the progress of keratinocyte-inducing osteoclastogenesis. RESULTS: The matrix of cholesteatoma was composed of a thicker stratum corneum than normal skin. The stratum corneum thickness and the expression of Keratin 10 positively correlated to the severity of bone destruction. Animal models revealed that the bone destruction induced by a higher keratinized epidermis was more severe. Osteoclasts were detected in bone erosion areas, and the number of osteoclasts increased with the keratinization degrees of the graft. In vitro studies showed that keratinocytes directly promoted monocytes differentiating into osteoclasts. CONCLUSIONS AND SIGNIFICANCE: In acquired cholesteatoma, the degree of keratinization correlated with disease severity, and keratinocytes directly promote osteoclastogenesis.

Experimental cholesteatoma: a comparison between spontaneous and induced models.

OBJECTIVE: To compare the incidence and the histopathological aspect of spontaneous and two induced Mongolian gerbils' models of cholesteatoma: External Auditory Canal (EAC) obliteration model and the Auditory Tube (AT) cauterization model. METHODS: Fifty-four ears of 27 animals were divided into EAC obliteration, AT cauterization, and control groups and histologically assessed for cholesteatoma incidence and classification at intervals of 2, 4, 8, and 16 weeks. RESULTS: Cholesteatoma was diagnosed in 30 of the 53 ears evaluated with a significantly higher incidence in groups that received some type of intervention (p<0.0001). It was not possible to histologically distinguish cholesteatomas of the same stage between the study groups. CONCLUSION: Although we observed a significant increase in cholesteatoma incidence with the two methods used when compared to the control group, all developed cholesteatomas were apparently identical from a histological point of view.

Syringocystadenoma Papilliferum Revealed 12 Years After Surgical Treatment of Chronic Ear with Cholesteatoma: Presentation of an Unusual Case and Literature Review.

Syringocystadenoma papilliferum is a rare hamartomatous adnexal tumor and appears mainly in the head and neck region. Rarely, such tumors may appear in the external auditory canal. There are only 14 described cases of the syringocystadenoma papilliferum in the external auditory canal in the Medline database. In this study, we present the first reported case of syringocystadenoma papilliferum arising in the modified radical mastoidectomy and occurring 12 years after ear surgery. A 26-year-old man was admitted to our clinic with complaints of discharge from the left ear, ear fullness, and hearing loss. These symptoms had been worsening for 3 years. Twelve years previously, he had undergone modified radical mastoidectomy by Bondy due to a cholesteatoma. Otoscopic examinations revealed otorrhea and a reddish mass measuring 1 × 0.8 cm arising from the tegmen tympanum and fundus of the mastoid cavity. A surgical biopsy was conducted with local anesthesia in the medical outpatient clinic, and it revealed syringocystadenoma papilliferum. A tumor resection was performed with a retroauricular approach. The bone attachment of the tumor was drilled out, and the ear cavity was covered with a mashed split skin graft. The ear cavity healed, and no tumor recurrence was observed during a 9-month follow-up period. Our case and literature analysis of previously described cases led to the conclusion that cases of syringocystadenoma papilliferum of the external auditory canal may be associated with different medical histories, age distributions, and origins than other syringocystadenoma papilliferums of the head and neck region. Tubular adenoma may occur together with syringocystadenoma papilliferum in 20% of cases. Malignant transformation of syringocystadenoma papilliferum may occur but is extremely rare. Computed tomography imaging may predict malignancy of the tumor. Tumors specific to the external auditory canal may occur in the modified radical mastoidectomy after middle ear surgery.

Automated multi-class classification for prediction of tympanic membrane changes with deep learning models.

BACKGROUNDS AND OBJECTIVE: Evaluating the tympanic membrane (TM) using an otoendoscope is the first and most important step in various clinical fields. Unfortunately, most lesions of TM have more than one diagnostic name. Therefore, we built a database of otoendoscopic images with multiple diseases and investigated the impact of concurrent diseases on the classification performance of deep learning networks. STUDY DESIGN: This retrospective study investigated the impact of concurrent diseases in the tympanic membrane on diagnostic performance using multi-class classification. A customized architecture of EfficientNet-B4 was introduced to predict the primary class (otitis media with effusion (OME), chronic otitis media (COM), and 'None' without OME and COM) and secondary classes (attic cholesteatoma, myringitis, otomycosis, and ventilating tube). RESULTS: Deep-learning classifications accurately predicted the primary class with dice similarity coefficient (DSC) of 95.19%, while misidentification between COM and OME rarely occurred. Among the secondary classes, the diagnosis of attic cholesteatoma and myringitis achieved a DSC of 88.37% and 88.28%, respectively. Although concurrent diseases hampered the prediction performance, there was only a 0.44% probability of inaccurately predicting two or more secondary classes (29/6,630). The inference time per image was 2.594 ms on average. CONCLUSION: Deep-learning classification can be used to support clinical decision-making by accurately and reproducibly predicting tympanic membrane changes in real time, even in the presence of multiple concurrent diseases.

Clinical Analysis of 85 Cases of External Auditory Canal Cholesteatoma Surgery under Specialized Endoscopy.

Objective: To investigate the clinical characteristics, surgical experience, and surgical outcomes of external auditory canal cholesteatoma (EACC) surgery under endoscopic otolaryngoscopy. Methods: A retrospective analysis of 85 EACC cases admitted to the Department of Otolaryngology, Renji Hospital, Shanghai Jiaotong University School of Medicine, from January 2016 to February 2021 was performed, followed by retrospective analysis of clinical data to explore the feasibility and clinical characteristics of all-oral endoscopic EACC surgery. A total of 85 EACC patients (90 ears) with a mean age of 49.93 ± 14.87 years were included in the study. According to Udayabhanu staging, 43 ears (47.78%) were stage I, 40 ears (44.44%) were stage II, and 7 ears (7.78%) were stage III. All patients underwent transendoscopic surgery. Results: 79 ears (87.78%) underwent endoscopic EACC resection alone (+external auditory canal tumor resection/tympanostomy tube insertion), 9 ears (10%) underwent endoscopic EACC resection+tympanostomy+tympanoplasty, 1 ear (1.11%) underwent endoscopic EACC resection+tympanoplasty, and 2 ears (2.22%) underwent EACC resection+otolaryngotomy+tympanoplasty+auditory chain reconstruction endoscopically. Of these, 7 ears (7.78%) underwent auricular cartilage-chondroplasty and 2 ears (2.22%) underwent auricular cartilage membrane repair. All patients were reviewed at 1 week, 2 weeks, 1 month, 3 months, 6 months, and 1 year postoperatively. One patient with stage II external auditory atresia had a recurrence after 6 months and underwent endoscopic ear surgery (ESS) again. One patient with stage 2 atresia recurred after 1 year and again underwent endoscopic ear surgery. The rest of the patients recovered well after the surgery, and the grafts healed well. Conclusion: EACC surgery through the external ear canal under a dedicated endoscope is a safe, reliable, and effective method. Patients with stage I and II external auditory canal cholesteatoma surgery under endoscopy have a rapid postoperative recovery with significant hearing improvement, and stage IIIA patients can also achieve good results under strict evaluation of indications.

[Diagnosis and surgical outcomes in the management of petrous bone cholesteatoma]. / Diagnostika i effektivnost' khirurgicheskogo lecheniya kholesteatomy piramidy visochnoi kosti.

OBJECTIVE: To evaluate the effectiveness of surgical treatment of patients with petrous bone cholesteatoma (PBC) depending on the localization of the pathological process. MATERIAL AND METHODS: The analysis of surgical treatment using various surgical approaches and its results in 32 patients with PBC, depending on the type, localization in petrous bone and intraoperative findings, is presented. Patients with supralabirint PBC underwent extended atticoantromastoidotomy with tympanoplasty and mastoidoplasty with automaterials (n=19), labyrinthectomy (n=4), subtotal petrozectomy with labyrinthectomy and suturing of the external auditory meatus (EAM) (n=2). In infralabirint and infralabirint-apical PBC, a transotic approach was used with Rambo suturing of EAM (n=9). The pre-sigmoid approach was performed in 1 patient. With an extradural subtemporal approach, PBC of apical localization was removed in 1 case. RESULTS: After surgical treatment, hearing remained at the same level in 15 (47%) patients, 14 of them had deafness. In the early postoperative period, a temporary increase in bone conduction hearing thresholds by 10-20 dB was detected in 14 (44%) patients with their gradual recovery over 3 months. Deafness in the postoperative period developed in 3 (9%) patients after removal of supralabirint cholesteatoma. In the early postoperative period, 3 (9%) patients developed systemic dizziness, which was stopped after 3 months. In 25 (78%) patients, the function of the facial nerve in the early postoperative period remained at the same level, of which 14 (44%) were normal, and 11 (34%) had the same degree according to the House-Brackmann (HB) classification. Improvement of function by one degree of HB classification was observed in 4 (12.5%) patients on average 5 months after surgery. CONCLUSION: An adequate personalized choice of surgical treatment methods allowed mainly to preserve the function of hearing and facial nerve. In cases of deterioration of facial nerve function in the postoperative period, gradual improvement was observed for 3-10.5 months with further positive dynamics.

Fibrous dysplasia: rare manifestation in the temporal bone / Displasia fibrosa: manifestação rara no osso temporal

Abstract Introduction: Fibrous dysplasia is a benign disorder, in which normal bone is replaced by fibrosis and immature bone trabeculae, showing a similar distribution between the genders, and being more prevalent in the earlier decades of life. Fibrous dysplasia of the temporal bone is a rare condition, and there is no consensus as to whether it is more common in monostotic or polyostotic forms. External auditory meatus stenosis and conductive dysacusis are the most common manifestations, with cholesteatoma being a common complication, whereas the involvement of the otic capsule is an unusual one. Surgical treatment is indicated to control pain or dysacusis, otorrhea, cholesteatoma, and deformity. Objectives: To describe the clinical experience of a tertiary referral hospital with cases of fibrous dysplasia of the temporal bone. Methods: Sampling of patients diagnosed with fibrous dysplasia of the temporal bone, confirmed by tomography, treated at the pediatric otology and otorhinolaryngology outpatient clinics, between 2015 and 2018. The assessed variables were age, gender, laterality, external auditory meatus stenosis, deformity, hearing loss, presence of secondary cholesteatoma of the external auditory meatus, lesion extension and management. Results: Five patients were included, four females and one male, with age ranging from 13 to 34 years. Three had the polyostotic form and two the monostotic form of fibrous dysplasia of the temporal bone. Four patients had local deformity and external auditory meatus stenosis, two of which progressed to cholesteatoma. All patients showed some degree of hearing impairment. All had preserved otic capsule at the tomography. Two patients are currently undergoing clinical observation; two were submitted to tympanomastoidectomy due to secondary cholesteatoma; one was submitted to lesion resection, aiming to control the dysacusis progression. Conclusion: Five cases of fibrous dysplasia of the temporal bone were described, a rare disorder of which the otologist should be aware.

Resumo Introdução: Displasia fibrosa é uma desordem benigna, na qual o osso é substituído por fibrose e trabeculado ósseo imaturo, com distribuição semelhante entre sexos, mais comum nas primeiras décadas de vida. O acometimento do osso temporal pela displasia fibrosa é raro, não há consenso se é mais comum nas formas monostóticas ou poliostóticas. Estenose do meato acústico externo e disacusia condutiva são as manifestações mais comuns. Colesteatoma é também uma complicação comum e o acometimento da cápsula ótica incomum. O tratamento cirúrgico está indicado para controle de dor ou disacusia, otorreia, colesteatoma, deformidade. Objetivos: Descrever a experiência clínica de hospital terciário de referência com casos de displasia fibrosa do osso temporal. Método: Amostragem dos pacientes com diagnóstico de displasia fibrosa do osso temporal, confirmado pela tomografia, atendidos nos ambulatórios de otologia e otorrinolaringologia pediátrica, entre 2015 e 2018. As variáveis avaliadas foram idade, gênero, lateralidade, estenose do meato acústico externo, deformidade, perda auditiva, presença de colesteatoma secundário de meato acústico externo, extensão da lesão e conduta adotada. Resultados: Foram incluídos cinco pacientes, quatro do sexo feminino e um masculino, de 13-34 anos. Três apresentaram a forma poliostótica da displasia fibrosa do osso temporal e dois a forma monostótica. Quatro apresentaram deformidade local e estenose do meato acústico externo, dois desses evoluíram com colesteatoma. Todos manifestaram algum grau de comprometimento auditivo. Todos apresentaram cápsula ótica preservada na tomografia. Duas pacientes estão em observação clínica; duas foram submetidas a timpanomastoidectomia devido a colesteatoma secundário; um foi submetido a ressecção da lesão para controle de progressão da disacusia. Conclusão: Foram descritos cinco casos de displasia fibrosa do osso temporal, desordem rara para a qual o otologista deve estar atento.

Hypertrophic Pachymeningitis of the Internal Auditory Canal Induced by a Labyrinthine Fistula Complicated With Cholesteatoma.

Hypertrophic pachymeningitis (HP) is defined by inflammation and thickening of the dura mater, and the etiologic factors are idiopathic or secondary to various conditions. To date, HP in the internal auditory canal (IAC) has rarely been reported. There have only been 3 reports of HP in the IAC. Magnetic resonance imaging showed enhancement of along the IAC and vestibule. After antibiotic treatment, enhancement was reduced with visible seventh and eighth nerves. The patient underwent tympanomastoidectomy. To our knowledge, this is the first case of HP associated with a labyrinth fistula complicated by cholesteatoma. We report MRI image with literatures.

Fibrous dysplasia: rare manifestation in the temporal bone.

INTRODUCTION: Fibrous dysplasia is a benign disorder, in which normal bone is replaced by fibrosis and immature bone trabeculae, showing a similar distribution between the genders, and being more prevalent in the earlier decades of life. Fibrous dysplasia of the temporal bone is a rare condition, and there is no consensus as to whether it is more common in monostotic or polyostotic forms. External auditory meatus stenosis and conductive dysacusis are the most common manifestations, with cholesteatoma being a common complication, whereas the involvement of the otic capsule is an unusual one. Surgical treatment is indicated to control pain or dysacusis, otorrhea, cholesteatoma, and deformity. OBJECTIVES: To describe the clinical experience of a tertiary referral hospital with cases of fibrous dysplasia of the temporal bone. METHODS: Sampling of patients diagnosed with fibrous dysplasia of the temporal bone, confirmed by tomography, treated at the pediatric otology and otorhinolaryngology outpatient clinics, between 2015 and 2018. The assessed variables were age, gender, laterality, external auditory meatus stenosis, deformity, hearing loss, presence of secondary cholesteatoma of the external auditory meatus, lesion extension and management. RESULTS: Five patients were included, four females and one male, with age ranging from 13 to 34 years. Three had the polyostotic form and two the monostotic form of fibrous dysplasia of the temporal bone. Four patients had local deformity and external auditory meatus stenosis, two of which progressed to cholesteatoma. All patients showed some degree of hearing impairment. All had preserved otic capsule at the tomography. Two patients are currently undergoing clinical observation; two were submitted to tympanomastoidectomy due to secondary cholesteatoma; one was submitted to lesion resection, aiming to control the dysacusis progression. CONCLUSION: Five cases of fibrous dysplasia of the temporal bone were described, a rare disorder of which the otologist should be aware.

Endoscopic Surgery of Congenital Cholesteatoma in the Anterior Epitympanic Recess: A Case Report of a Rare Location.

Congenital cholesteatoma is a whitish mass in the middle ear medial to an intact tympanic membrane. It is often without symptoms and therefore incidentally diagnosed. Pediatric congenital cholesteatoma generally starts as a small pearl-like mass in the middle ear cavity that eventually expands to involve the ossicles, epitympanum, and mastoid. The location, size, histopathological type, and extent of the mass must be evaluated to select the appropriate surgical method. Although microscopic ear surgery has traditionally been performed to remove congenital cholesteatoma, a recently introduced alternative is endoscopic surgery, which allows a minimally invasive approach and has better visualization. Here, we report the first known case of a patient with congenital cholesteatoma in the anterior epitympanic recess and discuss the utility of an endoscopic approach in the removal of a congenital cholesteatoma in the hidden area within the middle ear.

The aetiology of ossicular chain defects in congenital cholesteatoma.

OBJECTIVE: The aim of the present study was to perform a retrospective review of the lesion sites in congenital middle-ear cholesteatoma and any accompanying ossicular defects, as well as to explore the possible aetiology of congenital middle-ear cholesteatoma associated with such ossicular chain defects. METHOD: The clinical characteristics and pathogenic mechanisms of ossicular chain defects were investigated in 10 patients with early-stage congenital middle-ear cholesteatoma confirmed by surgery, from August 2011 to February 2019. RESULTS: Monofocal cholesteatoma was located in the anterosuperior quadrant in 3 cases and in the posterosuperior quadrant in 7 cases; all 10 cases showed an absence of the long crus of incus, and 8 cases showed a complete or partial absence of stapes superstructure. The lesions were confined to the vestibular window and the stapes region and had no contact with the long crus of the incus or stapes in nine cases. None of the 10 patients had any recurrence of cholesteatoma. CONCLUSION: Although cholesteatoma can cause erosion of ossicles, the present cases suggest that residual epithelium of the cholesteatoma may coexist with ossicular malformations. Therefore, the aetiology of the clinical characteristics in these patients may derive from residual epithelial hinderance of ossicle development.

Detection of respiratory viruses in primary cholesteatoma tissues.

Cholesteatomas are frequent middle ear benign tumors of unknown etiology. Infectious agents have been considered as possible contributing factors in the pathogenesis of cholesteatomas. Aiming to investigate the presence of respiratory viruses in primary cholesteatoma tissues, 26 formalin-fixed paraffin-embedded primary cholesteatoma tissues obtained from patients seen at the of the Clinical Hospital of the University of São Paulo School of Medicine, in Ribeirão Preto, Brazil were tested by real-time polymerase chain reaction (PCR). Considering the PCR results, 35% of the tissues were positive for human rhinovirus (HRV), 15.3% for human enterovirus (EV), 3.8% for human metapneumovirus (HMPV), and 3.8% for human bocavirus (HBoV). Serial immunohistochemistry for virus antigens and cell surface markers evidenced that the viruses were associated with fibroblasts, dendritic cells, macrophages, B lymphocytes, CD4+ , and CD8+ T lymphocytes. These findings indicate for the first time the presence of active respiratory virus infection in primary cholesteatoma tissues, suggesting that persisting virus infection in the middle could play a role in the pathogenesis and evolution of cholesteatomas.

Association of Matrix Metalloproteinase-2 mRNA Expression with Subtypes of Pediatric Cholesteatoma.

OBJECTIVE: Cholesteatoma is a clinically heterogeneous disease, with some patients showing spontaneous regression, while others experiencing an aggressive, lethal disease. Cholesteatoma in children can be divided into two types: congenital and acquired. Identifying good prognostic markers is needed to help select patients who will require immediate surgical intervention. Matrix metalloproteinase-2 (MMP2) was previously reported to play an important role in cholesteatoma progression, by promoting bone destruction and keratinocyte infiltration. Herein, we analyzed MMP2 mRNA expression level in cholesteatoma using RNA-in situ hybridization in formalin-fixed, paraffin-embedded (FFPE) tissue samples. METHODS: Sixty patients with cholesteatoma under 15 years old, who underwent their primary surgery at Aichi Medical University's Otolaryngology Department, were analyzed for MMP2 expression level, using RNA-in situ hybridization. RESULTS: There were no significant differences in MMP2 mRNA expression level between congenital cholesteatoma and acquired cholesteatomas. In congenital cholesteatoma, higher MMP2 signals were observed in the open type than in the closed type (p < 0.001). In acquired cholesteatoma, higher MMP2 signals were observed in the pars tensa than in the pars flaccida (p < 0.001). MMP2 mRNA expression level was almost exclusively found in the fibroblasts or in the inflammatory cells in the stroma, but not in the epithelium. CONCLUSION: Our study reveals that MMP2 mRNA expression level is strongly associated with the subtypes of cholesteatoma. The findings suggest that the level of expression of MMP2 mRNA may be related to the pathogenesis and aggressive features of cholesteatoma.

Cytokine secretion and pyroptosis of cholesteatoma keratinocytes mediated by AIM2 inflammasomes in response to cytoplasmic DNA.

Cholesteatoma constitutes an acquired benign epidermal non­permanent bone lesion that is locally destructive and patients often relapse. Inflammasomes, which mediate the maturation and production of IL­18 and IL­1ß, resulting in pyroptosis, have been documented to serve a core function in multiple inflammatory conditions. Absent in melanoma 2 (AIM2) is an inflammasome that identifies cytoplasmic DNA and has previously been reported as a pivotal modulator of inflammatory responses. Therefore, the present study aimed to determine the expression levels of AIM2 in human cholesteatoma tissues, and elucidate its function in modulating cytokine production. The expression levels of IL­18, apoptosis­associated speck­like protein containing a CARD (ASC), IL­1ß, AIM2 and caspase­1 were markedly elevated in cholesteatoma tissues. Protein expression levels of AIM2, caspase­1 and ASC were localized in the cellular cytoplasm, primarily in the granular and prickle­cell layers in the cholesteatoma epithelium. Induction using IFN­Î³, as well as cytoplasmic DNA markedly activated the AIM2 inflammasome and elevated the release of IL­18 and IL­1ß in human cholesteatoma keratinocytes. IFN­Î³ was found to enhance poly(dA:dT)­induced pyroptosis of cells and cytokine production. The results of the present study revealed that AIM2 expressed in human cholesteatoma serves a vital function in the inflammatory response by initiating the inflammasome signaling cascade in cholesteatoma.

External Auditory Canal Cholesteatoma Causing Simultaneous Bezold Abscess and Sinus Thrombosis.

Extra- and intracranial complications of cholesteatoma are rare in the new era of antibiotics. The rarity of the severe complications and the atypical symptoms cause difficulties to set up proper diagnosis and treatment. We report about a 76-year old patient with external auditory canal cholesteatoma causing Bezold abscess and sigmoid sinus thrombosis. The patient underwent canal wall up mastoidectomy and mastoid obliteration with abdominal fat and Bezold abscess drainage. Systemic antibiotic and anticoagulant therapy were applied. The treatment resulted in fast improvement in the general condition of the patient, and the control magnetic resonance imaging (MRI) showed no recurrence of the disease. Laryngoscope, 131:E1282-E1285, 2021.