Murine model of eosinophilic chronic rhinosinusitis with nasal polyposis inducing neuroinflammation and olfactory dysfunction.

BACKGROUND: Chronic rhinosinusitis (CRS) is a common inflammatory condition affecting the nasal and paranasal sinus mucosa, often accompanied by olfactory dysfunction. Eosinophilic CRS with nasal polyps (ECRSwNP) is a subtype of CRS characterized by eosinophilic infiltration. Animal models for ECRSwNP with olfactory dysfunction are necessary for exploring potential therapeutic strategies. OBJECTIVE: The aim of this study was to establish a mouse model of ECRSwNP combined with olfactory dysfunction in a shorter time frame using intranasal ovalbumin and Aspergillus protease (AP) administration. The efficacy of the model was validated by evaluating sinonasal inflammation, cytokine levels, olfactory function, and neuroinflammation in the olfactory bulb. METHODS: Male BALB/c mice were intranasally administered ovalbumin and AP for 6 and 12 weeks to induce ECRSwNP. The resultant ECRSwNP mouse model underwent histologic assessment, cytokine analysis of nasal lavage fluid, olfactory behavioral tests, and gene expression profiling to identify neuroinflammatory markers within the olfactory bulb. RESULTS: The developed mouse model exhibited substantial eosinophil infiltration, increased levels of inflammatory cytokines in nasal lavage fluid, and confirmed olfactory dysfunction through behavioral assays. Furthermore, olfactory bulb inflammation and reduced mature olfactory sensory neurons were observed in the model. CONCLUSION: This study successfully established a validated mouse model of ECRSwNP with olfactory dysfunction within a remarkably short span of 6 weeks, providing a valuable tool for investigating the pathogenesis and potential therapies for this condition. The model offers an efficient approach for future research in CRS with nasal polyps and olfactory dysfunction.

Perineural invasion is a poor prognostic factor for sinonasal squamous cell carcinoma.

OBJECTIVES: In this study, our primary objective is to elucidate the correlation between sinonasal squamous cell carcinoma (SCC) and perineural invasion (PNI), a topic that has received limited attention in prior literature. Furthermore, we have undertaken an examination of various other clinicopathological factors. MATERIALS AND METHODS: We retrospectively reviewed the medical records of patients aged ≥ 20 years with newly diagnosed sinonasal cancer and received treatment and care at a tertiary medical center. We excluded patients who did not have an SCC diagnosis, those who underwent palliative surgery, and individuals with insufficient follow-up data at the study endpoint. Ultimately, a total of 49 eligible participants were included in our further analysis. RESULTS: PNI and advanced T staging were associated with increased risk of local recurrence (LR). Furthermore, PNI was significantly associated with an adverse prognosis in terms of LR-free survival. Participants with PNI had significantly worse overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS). Patients with LR had significantly worse OS, DFS, and DSS. CONCLUSION: PNI is associated with an elevated risk of LR and reduced OS, DFS, and DSS in patients with sinonasal SCC. These findings can facilitate the formulation of more targeted and effective treatment strategies for sinonasal SCC in clinical practice.

Using Surgicel-wrapped Merocel to reduce pain during the removal of nasal packing.

BACKGROUND: Merocel is a commonly used material for nasal packing; nevertheless, the majority of patients experience pain when the nasal packing is removed.Aims/Objectives: This study aims to introduce a novel technique for nasal packing using Surgicel-wrapped Merocel. MATERIAL AND METHODS: Patients who underwent septoplasty received either Merocel or Surgicel-wrapped Merocel as nasal packing. Clinical complications related to bleeding and subjective symptoms associated with the packing materials were assessed. RESULTS: Between 2018 and 2021, a total of thirty-three patients with a deviated nasal septum underwent septoplasty. Among them, eight patients received Merocel nasal packing, while twenty-five patients were treated with the new nasal packing technique involving Surgicel-wrapped Merocel. We observed a significant reduction in pain during removal in the Surgicel-wrapped Merocel group compared to the Merocel group (p = .008). However, no significant differences were noted in other discomforts related to packing or bleeding after removal between these two groups.Conclusions and Significance:Using Surgicel-wrapped Merocel as nasal packing following septoplasty is an effective method to alleviate pain during removal.

Lipopolysaccharide-Initiated Rhinosinusitis Causes Neuroinflammation and Olfactory Dysfunction in Mice.

BACKGROUND: Olfactory dysfunction is a common disease and it may be caused by sinonasal inflammation, toxin inhalation, or neurological disorders. After sinonasal inflammation, if both olfactory neuroinflammation and olfactory dysfunction occur still under investigation. OBJECTIVE: This study aimed to investigate whether neuroinflammation and olfactory dysfunction occur after lipopolysaccharide (LPS)-initiated rhinosinusitis. METHODS: Adult C57BL/6 mice were intranasally administered with LPS for 3 weeks. The olfactory function was evaluated with a buried food test. The inflammatory status of sinonasal cavity and olfactory bulb was evaluated with histology and biochemistry. RESULTS: After 3-week LPS treatment, mice developed olfactory dysfunction, sinonasal cavity, and olfactory bulb inflammation. LPS-treated mice had greater sinonasal mucosal thickness. Besides, pro-inflammatory interleukin-6, the number of goblet cells and neutrophils in the sinonasal cavity was increased after LPS administration. The olfactory sensory neurons in the olfactory epithelium and the olfactory bulb were decreased, and the olfactory function was impaired by LPS administration. Inflammatory cytokines such as interferon-γ and tumor necrosis factor-α were increased in the olfactory bulb. CONCLUSION: This study showed that LPS-initiated rhinosinusitis caused olfactory neuroinflammation and olfactory dysfunction in mice.

Antipsychotic drug trifluoperazine as a potential therapeutic agent against nasopharyngeal carcinoma.

BACKGROUND: Trifluoperazine (TFP) is a typical antipsychotic primarily used to treat schizophrenia. In this study, we aimed to evaluate whether TFP can be used as a therapeutic agent against nasopharyngeal carcinoma (NPC) and identify its underlying molecular mechanisms. METHODS: We used NPC-TW01, TW03, TW04, and BM to assess the anticancer effects of TFP by using cytotoxicity, wound healing, colony formation, and cell invasion assays. An in vivo animal study was conducted. RNA sequencing combined with Ingenuity Pathways Analysis was performed to identify the mechanism by which TFP influences NPC cells. RESULTS: Our data revealed that TFP decreased NPC cell viability in a dose-dependent manner. The invasion and migration of NPC tumor cells were inhibited by TFP. An in vivo study also demonstrated the anticancer effects of TFP. RNA sequencing revealed several anticancer molecular mechanisms following TFP administration. CONCLUSIONS: The antipsychotic drug TFP could be a potential therapeutic regimen for NPC treatment.

Clinicopathological Features and Prognostic Factors of Sinonasal Rhabdomyosarcoma.

BACKGROUND/AIM: Sinonasal rhabdomyosarcoma (RMS) is a rare soft tissue malignancy. Due to the limited cases, the clinicopathological features and prognostic factors are still not well understood. PATIENTS AND METHODS: This retrospective review included eight patients with sinonasal RMS at our institution between 2004 and 2020. Patient demographics, tumor features, Intergroup Rhabdomyosarcoma Study Group (IRSG) stage and clinical group, treatment strategy, and survival rates were evaluated. Kaplan-Meier analysis and log-rank tests were performed to analyze the possible prognostic factors. RESULTS: We observed a predominance of male sex and alveolar-type tumor in sinonasal RMS. Nasal obstructions and neck masses were the most common symptoms. Patients with pretreatment lactate dehydrogenase (LDH) levels >400 U/l and negative immunohistochemical staining for desmin or MyoD1 had lower survival rates. CONCLUSION: In patients with sinonasal RMS, pretreatment LDH levels >400 U/l and negative immunohistochemical staining for desmin or MyoD1 may suggest a poor prognosis. These factors can not only contribute to the prediction of prognosis in patients with sinonasal RMS but also facilitate the design of more appropriate treatment strategies.

Prior cancer history predicts the worse survival of patients with nasopharyngeal carcinoma.

PURPOSE: Previous cancers can be observed in patients with nasopharyngeal carcinoma (NPC). However, whether prior cancer diagnosis affects survival outcomes remains unknown. This study aimed to explore the impact of prior cancer on the survival of patients with NPC. METHODS: We retrospectively collected data from 666 NPC patients between 2006 and 2018. The patients in this study were divided into those without prior cancer, with prior head and neck cancer, and prior non-head and neck cancer. The demographic data and survival of these groups were then analyzed. The independent prognostic factors for NPC were determined using multivariate Cox regression analysis. RESULTS: We identified 25 NPC patients with prior cancer in our case series, most of whom had a history of colorectal cancer. Patients with a history of cancer were older than those without a history of cancer (p = 0.001). In the subgroup analysis stratified by the timing of prior cancer, NPC patients with prior non-head and neck cancer within 24, 36, 60, and 120 months showed worse survival than patients without prior cancer (all p < 0.05). When stratified by cancer stage, stage III NPC patients with prior non-head and neck cancer showed worse survival than patients without prior cancer (p < 0.001). Prior cancer and diabetes can predict worse survival in patients with stage III NPC. CONCLUSION: This study demonstrated that prior cancer and diabetes are independent prognostic factors in patients with stage III NPC.

Vertebral artery stenosis predicts cerebrovascular diseases following radiotherapy for nasopharyngeal carcinoma.

PURPOSE: Radiotherapy for nasopharyngeal carcinoma (NPC) may induce cerebrovascular diseases including ischemic stroke and transient ischemic attack (TIA), which can cause severe disability. However, information on the incidence and predictors of cerebrovascular diseases is scarce. This study aimed to estimate the incidence of cerebrovascular diseases following NPC, and attempts to ascertain the predictors of cerebrovascular diseases to facilitate early prevention. METHODS: We performed a retrospective cohort study on 655 NPC patients who received radiotherapy between 2006 and 2018 in a medical center. This study analyzed the incidence, clinical and imaging presentation of patients with cerebrovascular diseases. Cox proportional hazard model was used to identify risk factors associated with cerebrovascular diseases following radiotherapy. RESULTS: There were 14 patients who developed an ischemic stroke, and 3 patients developed a TIA after a mean follow-up of 5.8 years. Most ischemic events were from large-artery atherosclerosis (76.5%), and the most common symptom of ischemic stroke was unilateral limb weakness (57.1%). The cumulative incidence of ischemic stroke or TIA 15 years after radiotherapy was 9.1% (95% confidence interval [CI] = 4.7-17.2%). Multivariate Cox regression identified vertebral artery stenosis (HR: 18.341; 95% CI = 3.907-86.100; P < 0.001), atrial fibrillation (HR: 13.314; 95% CI = 1.306-135.764; P = 0.029), and hypertension (HR: 7.511; 95% CI = 1.472-38.320; P = 0.015) as independent predictors of ischemic stroke or TIA. CONCLUSION: Our study found that NPC patients with vertebral artery stenosis, atrial fibrillation, or hypertension carry a higher risk for ischemic stroke or TIA. Regular assessment of vertebral artery after radiotherapy was suggested.

Pantoea dispersa rhinosinusitis: clinical aspects of a rare sinonasal pathogen.

PURPOSE: There is no report in the literature targeting the role of Pantoea dispersa in rhinosinusitis and P. dispersa has not been identified as a commensal bacterium in the sinonasal cavity. We aimed to investigate the role of P. dispersa in rhinosinusitis. METHODS: We retrospectively reviewed the data of patients diagnosed with rhinosinusitis at a medical center in Taiwan. RESULTS: A total of 274 rhinosinusitis patients underwent sinus culture between July 2017 and July 2019. All 23 patients with acute P. dispersa rhinosinusitis experienced purulent rhinorrhea; three (13%) had nasal obstruction, but none had olfactory dysfunction, facial pressure/pain and nasal polyp. The patients with P. dispersa received a significantly shorter duration of antibiotic treatment (19.9 ± 2.6 vs. 28.9 ± 2.5 days, P = 0.015) and had lower surgery rate (0% vs. 16.7%, P = 0.043) than other patients. Patients with olfactory dysfunction were more likely to receive surgical treatment (P = 0.018). CONCLUSION: Acute rhinosinusitis caused by P. dispersa resulted in less surgical interventions and shorter treatment durations. Olfactory dysfunction may imply longer course and possibility for surgical intervention in chronic rhinosinusitis. The present study revealed that P. dispersa had the potential to colonize in human sinonasal cavities and cause rhinosinusitis.

The role of nasopharyngectomy in the management of nasopharyngeal carcinoma.

PURPOSE OF REVIEW: Recently, endoscopic nasopharyngectomy (ENPG) has become an effective treatment for locally recurrent nasopharyngeal carcinoma (NPC). This article reviews recent publications on ENPG and specifically addresses the surgical anatomy of the nasopharynx and discusses several important issues regarding ENPG. RECENT FINDINGS: The surgical techniques for ENPG have been previously described in several studies. The latest published data revealed good outcomes of ENPG compared with intensity-modulated radiation therapy (IMRT) in recurrent NPC. In addition, ENPG avoids severe reirradiation side effects. This review highlights the surgical anatomy of ENPG, which is important in preventing possible serious complications. SUMMARY: ENPG is a good option for managing recurrent NPC. Careful preoperative evaluation and a full understanding of the surgical anatomy help in preventing damage to nearby critical neurovascular structure. Long-term follow-up is still needed to evaluate its eventual morbidity and efficacy.

Pretreatment age and serum lactate dehydrogenase as predictors of synchronous second primary cancer in patients with nasopharyngeal carcinoma.

OBJECTIVES: Nasopharyngeal carcinoma (NPC) is a common cancer and is treated primarily by chemotherapy and radiotherapy. However, NPC with synchronous second primary cancer (SSPC) is very rare and its risk factors, treatment and prognosis remain unclear. In this study, we aimed to analyze patients with NPC and SSPC, and attempt to find potential predictors for these patients. MATERIALS AND METHODS: We retrospectively collected 681 patients with NPC from 2006 to 2018. Patients in this study were divided into two groups: those patients with SSPC and those without SSPC. We then analyzed the demographic data and survival of these two groups. Independent predictors of SSPC were determined by multivariate regression analysis. A comprehensive review of the literature was also performed. RESULTS: We identified 17 NPC patients with SSPC in our case series and 13 cases in the literatures, and the most common SSPC is lung (16.1%). In univariate analysis, NPC patients with SSPC had older age (P < 0.001) and higher serum lactate dehydrogenase (LDH) (P = 0.008), compared with those without SSPC. In multivariate analysis, old age (P = 0.001) and high serum LDH (P = 0.023) remained independent predictors of SSPC, and a predictive equation model was established. NPC patients with SSPC had a significantly lower 5-year disease-specific survival rate compared with patients without SSPC (34.0% vs. 77.6%, P < 0.001) CONCLUSION: This study demonstrated that pretreatment age and serum LDH were independent predictors for SSPC in NPC patients. These independent factors can be used for early detection, and better facilitate the design of more appropriate treatment by medical professionals.

Soluble epoxide hydrolase inhibition enhances anti-inflammatory and antioxidative processes, modulates microglia polarization, and promotes recovery after ischemic stroke.

BACKGROUND: Ischemic stroke triggers inflammatory responses and oxidative stress in the brain, and microglia polarization affects the degree of neuroinflammation. It has been reported that the inhibition of soluble epoxide hydrolase (sEH) activity protects brain tissue. However, the anti-inflammatory and antioxidative effects of sEH inhibition in the ischemic brain are not fully understood. This study aimed to investigate the effects of a selective sEH inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), after ischemic stroke. METHODS: Adult male rats with middle cerebral artery occlusion (MCAO) were administered with AUDA or a vehicle. Behavioral outcome, infarct volume, microglia polarization, and gene expression were assessed. RESULTS: Rats treated with AUDA showed better behavioral outcomes and smaller infarct volumes after MCAO. After AUDA treatment, a reduction of M1 microglia and an increase of M2 microglia occurred at the ischemic cortex of rats. Additionally, there was an increase in the mRNA expressions of antioxidant enzymes and anti-inflammatory interleukin-10, and pro-inflammatory mediators were decreased after AUDA administration. Heme oxygenase-1 was mainly expressed by neurons, and AUDA was found to improve the survival of neurons. CONCLUSION: The results of this study provided novel and significant insights into how AUDA can improve outcomes and modulate inflammation and oxidative stress after ischemic stroke.

Predictors of hearing outcomes after stapes surgery in otosclerosis.

Background: The current surgical treatment of otosclerosis is stapes surgery; however, few studies have reported the predictors of surgical outcomes.Aim/objective: This study aimed to investigate the prognostic predictors for postoperative hearing outcomes.Materials and methods: A total of 181 ears in 152 patients undergoing stapes surgery at a tertiary referral centre in Taiwan from 1996 to 2016 were retrospectively enrolled and preoperative and intraoperative parameters were obtained. Univariate and multivariate analyses were used to determine independent predictors of postoperative hearing outcomes. A regression model was also established. Hearing success was defined as a postoperative air-bone gap (ABG) ≤10 dB.Results: In univariate analysis, the absence of floating footplate during surgery (p = .003) and small preoperative ABG (p = .014) were associated with successful hearing outcomes. Multivariate logistic regression analysis further revealed the absence of floating footplate during surgery (p = .010) and small preoperative ABG (p = .015) remained independent predictors of postoperative hearing success.Conclusions and significance: Preoperative audiometric data and intraoperative finding may provide surgeons and patients with a better insight into surgical outcomes.

Excessive Expression of Microglia/Macrophage and Proinflammatory Mediators in Olfactory Bulb and Olfactory Dysfunction After Stroke.

BACKGROUND/AIM: Olfactory dysfunction can be caused by stroke but the pathogenesis is still unclear. Previous studies have proved that olfactory dysfunction could be caused by microglia activation in the olfactory bulb and that middle cerebral artery occlusion (MCAO) may induce ipsilateral olfactory bulb microglia activation. This study aimed to explore the possible pathogenesis of ischemic stroke-induced olfactory dysfunction. MATERIALS AND METHODS: We used a rat model of MCAO to simulate ischemic stroke. Olfactory function tests were performed using buried food test. The mRNA expression of olfactory marker protein (OMP), microglia/macrophage activation, and proinflammatory mediators were measured using reverse transcription-quantitative polymerase chain reaction. RESULTS: Following MCAO, rats had poorer olfactory performance. In the olfactory bulb of the rats, the mRNA expression of OMP decreased and the mRNA expression of microglia/macrophage activation and proinflammatory mediators increased. CONCLUSION: Ischemic stroke causes microglia/macrophage activation and promotes neuroinflammation in the olfactory bulb, causing olfactory dysfunction.

Development of a Modified Surgical Technique for Simulating Ischemic Cerebral Cortex Injury in Rats.

BACKGROUND/AIM: Middle cerebral artery occlusion (MCAO) in rodents is an essential animal model for research focusing on ischemic stroke. To date, several kinds of surgical methods for MCAO have been developed and the craniotomy method has the advantage of direct visualization of the middle cerebral artery (MCA). MCAO at a more proximal site produces better surgical results, but it is a more invasive technique. The aim of this study was to evolve the surgical technique for simulating ischemic cerebral cortex injury in rats. MATERIALS AND METHODS: To approach proximal MCA with a less invasive procedure, a modified surgical technique for MCAO in rats was developed. Besides, rats receiving the modified and conventional method were compared with regard to infarct volume and by behavioral tests. RESULTS: Following craniotomy, we proposed that the inferior edge of the craniotomy should be enlarged with fine forceps. This modified surgical method induces larger infarct volume, significant behavioral impairment and can induce ischemic stroke. Additionally, it does not significantly increase the operation time, and has produced no obvious complications. CONCLUSION: This modified surgical technique may serve as a practical method for performing MCAO.

Inhibition of soluble epoxide hydrolase regulates monocyte/macrophage polarization and improves neurological outcome in a rat model of ischemic stroke.

It is generally understood that continuing neuroinflammation after ischemic stroke can exacerbate the brain damage. During the inflammatory hematogenous recruitment process, the monocytes and macrophages are activated into proinflammatory M1 and anti-inflammatory M2 cell types. Inhibition of soluble epoxide hydrolase (sEH) activity has been reported to regulate monocytes/macrophages, and attenuates neuroinflammation. This study aimed to evaluate whether a selective sEH inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), can regulate monocyte/macrophage polarization and improve motor function in the rats with ischemic stroke induced by middle cerebral artery occlusion. We measured the infarct volume with 2,3,5-triphenyltetrazolium chloride staining and used the rotarod test to assess motor performance in rats. The monocyte/macrophage activation and mRNA expression of proinflammatory mediators were measured by flow cytometry and reverse-transcription quantitative PCR, respectively. Our results showed better neurological function and less infarct volume in the rats treated with AUDA. Compared with the vehicle group, the AUDA-treated group showed a reduction in M1 monocyte/macrophage activation and proinflammatory mRNA expressions in the infarct cortex of rats. Our data suggest that the sEH inhibition may regulate monocyte/macrophage polarization and improve neurological outcome after ischemic stroke.

Pretreatment pain predicts perineural invasion in oral squamous cell carcinoma: A prospective study.

OBJECTIVES: Perineural invasion (PNI) is an established poor prognostic pathological feature for oral squamous cell carcinoma (OSCC). The purpose of this study was to analyze the role of pretreatment parameters in predicting PNI for OSCC. MATERIALS AND METHODS: We prospectively enrolled into our study 102 newly diagnosed OSCC patients, who were surgically treated from 2011 to 2012. Before treatment, patients completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire H&N35 and the visual analogue scale (VAS) for cancer pain. Pathological examination was performed to ascertain PNI status in all patients. Patients were divided into two groups, those with PNI and without PNI. Pretreatment parameters were compared between the two groups. RESULTS: In univariate analysis, clinical T classification (P<0.001), painkiller use (P=0.001), problem with social eating (P<0.001) and social contact (P=0.002), VAS scores of primary pain (P<0.001) and referred pain (P=0.004) were found to be associated with PNI. Multivariate logistic regression analysis further revealed VAS score of primary pain (P=0.001, OR 2.014) and T3-4 classification (P=0.014, OR 6.422) were independent predictors of PNI. A regression equation incorporating pretreatment pain was developed to predict the probability of having PNI. CONCLUSION: PNI can be predicted by higher pretreatment VAS score of primary pain, as well as more advanced clinical T classification. Careful evaluation of pretreatment pain of primary tumor can thus be helpful in improving treatment decision making for OSCC.

Chronic otitis media surgery and re-operation risk factor analysis: A nationwide retrospective cohort study of 18 895 patients.

CONCLUSION: Patients with risk factors including younger age, mastoiditis, external ear disease, treatment by older surgeons, and concomitant mastoidectomy should receive detailed management to minimize the probability of re-operation for chronic otitis media (COM). OBJECTIVES: Although COM remains a common ear disease requiring surgical intervention, its re-operation risks are less well-documented. This study aimed to compare patients with COM who underwent re-operation and those patients with no re-operation, and identify the risks of re-operation. METHOD: This retrospective cohort study analyzed the trend of COM surgery from 1999-2009, and identified the re-operation risks of 18 895 patients with COM who underwent surgery from 2002-2006 using the National Health Insurance Research Database in Taiwan. RESULTS: Among the study population, 129 patients underwent revision surgery during a 5.5 ± 1.5 year follow-up period. A univariate logistic regression analysis showed that the re-operation rate was significantly higher in patients under 18 years of age, those with mastoiditis, disorders of external ear, treatment by surgeons of 50-64 years of age, use of a very high volume surgeon, and combined surgery with mastoidectomy. A multivariate analysis further limited the re-operation risk factors to younger patients, those with mastoiditis, external ear disorders, treatment by older surgeons, and concomitant mastoidectomy.

Emergence of Refractory Otomastoiditis Due to Nontuberculous Mycobacteria: Institutional Experience and Review of the Literature.

BACKGROUND: Nontuberculous mycobacteria (NTM) infection has attracted increasing attention in recent years; however, NTM otomastoiditis is extremely rare. Surgery combined with antibiotic therapy is the current mainstay of treatment; however, the reported duration of medication still varies. In this study, we aimed to analyze patients with NTM otomastoiditis and establish a more efficient treatment strategy. METHODS: Medical records and temporal bone images of patients with NTM otomastoiditis were retrospectively analyzed. In addition, a comprehensive review of cases with NTM otomastoiditis in the literature was also performed. RESULTS: Twenty-two patients were identified in our institution, and all patients had refractory otorrhea. The rates of granulation tissue, otalgia, and facial palsy were 90.9%, 31.8%, and 9.1%, respectively. Soft tissue attenuation via imaging studies was demonstrated in all of the middle ear cavities. All patients received medical treatment, 20 (90.9%) underwent surgery, and 4 (18.2%) underwent revision surgery. The median time to cure was similar between the "prolonged-course" and "standard-course" antibiotic groups (3.0 vs 3.3 months; P = .807). However, the former had a longer median duration of antibiotic therapy (6.0 vs 3.0 months; P = .01). In the literature review, 54 (96.4%) patients received medical treatment, 51 (91.1%) underwent surgery, and 27 (48.2%) underwent revision surgery. CONCLUSIONS: NTM otomastoiditis should be suspected if a patient has chronic refractory otorrhea and ear granulation tissue. Surgery, which is the mainstay of treatment, should be complemented with antibiotics. In those without temporal bone osteomyelitis, antibiotic treatment can be stopped after a dry ear is achieved.