Extracapsular dissection (ECD) is typically indicated for small, benign parotid tumors. The surgical procedure for ECD does not involve the identification of the main trunk of the facial nerve. Although the nerve branches may become exposed during surgery, it is considered safer if they are not exposed. Therefore, we investigated the relationship between tumor location and size and intraoperative exposure of nerve branches in cases of ECD. The study included 61 cases that underwent ECD, with tumors meeting all of the following criteria preoperatively: tumor diameter ≤25 mm, superficial tumor, good mobility, and benign tumor. The tumor location was determined via magnetic resonance imaging, with the anterior–posterior axis classified into anterior, middle, and posterior regions, and the superior–inferior axis classified into superior, middle, and inferior regions. We compared 29 cases in which the nerve branches were identified (identified group) with 32 cases in which the nerve branches were not identified (nonidentified group). All three cases that developed transient facial nerve paralysis after surgery were included in the identified group. Excluding anterior tumors, nerve exposure was significantly more frequent in cases with a tumor diameter of ≥16 mm. The diameter of posterior tumors was significantly larger than that of anterior tumors; however, the nerve identification rate was significantly lower. Anterior tumors were significantly smaller in diameter than posterior tumors; however, no significant difference was observed in the nerve identification rate. These findings are likely influenced by tumor location and the course of the facial nerve. When the nerve is exposed or identified during ECD, there is an associated risk of postoperative transient facial nerve paralysis. Therefore, it is important to assess the likelihood of nerve identification based on tumor size and location before surgery.

Boron neutron capture therapy (BNCT) dose planning conventionally uses a tumor-to-blood (T/B) ratio derived from the tumor maximum standardized uptake value (SUVmax) of fluorine-18-labeled 4-borono-L-phenylalanine (1⁸F-BPA) positron emission tomography (PET) (individual model). It remains unclear whether tumor SUVmax or individual model doses predict outcomes in accelerator-based BNCT for head and neck cancer (HNC). We investigated the correlation of 1⁸F-BPA PET SUVmax and individual model doses with treatment response. We retrospectively analyzed 30 patients with HNC treated with accelerator-based BNCT (2020–2021). The Kaplan–Meier method was used for survival analysis. Dose parameters (Dmax, Dmin, and D80

Salivary duct carcinoma (SDC) is one of the most aggressive salivary gland carcinomas. Heterotopic ossification (HO) is the formation of mature bone in non-skeletal tissues. HO can occur in a number of neoplastic lesions. However, its occurrence is markedly rare in salivary gland neoplasms and to the best of our knowledge, SDC with HO has not yet been reported. Therefore, the present report describes the first reported case of SDC with HO in the parotid gland and reviews the clinicopathological features of salivary gland neoplasms with HO. A 38-year-old Japanese male presented with a mass in the left parotid region. Physical examination revealed a poorly mobile mass, measuring 2 cm, in the left parotid gland. Total left parotidectomy was performed. A number of metastases were observed in the bone and brain, despite postoperative anti-HER2 combination chemotherapy. Histopathological examination of the resected parotid gland tumour revealed invasive neoplastic growth comprising cribriform and papillary proliferations. These neoplastic cells exhibited a rich eosinophilic cytoplasm and large nuclei containing conspicuous nucleoli. In addition, the present report outlines peculiar finding in the presence of mature bone tissue within the tumour. Accordingly, a diagnosis of SDC with HO was made. Despite the detailed mechanisms underlying the occurrence of HO in salivary gland neoplasms remaining unclear, neoplastic myoepithelial cells may serve a role in the development of HO in pleomorphic adenoma and carcinoma ex pleomorphic adenoma. However, SDC exhibited no myoepithelial cell components, therefore the mechanism of HO in SDC may differ from that in PA.

Background/Objective: Eosinophilic chronic rhinosinusitis (ECRS) is a subtype of chronic rhinosinusitis with nasal polyps that is characterized by abundant eosinophilic infiltration within nasal polyps. Tuft cells are epithelial chemosensory cells that are present in the normal respiratory tract and activate group-2 innate lymphoid cells through their secretion of interleukin-25 and prostaglandin (PG) D2. ECRS is also characterized by the activation of group-2 innate lymphoid cells; however, the involvement of tuft cell-derived PGD2 in this process remains unclear. Methods: We selected consecutive patients with and without ECRS who underwent biopsy or surgical resection. Dual immunohistochemical analyses were performed to determine the presence of tuft cells producing PGD2, using POU class 2 transcription factor (POU2F3), a specific tuft cell marker, and hematopoietic prostaglandin D synthase (H-PGDS). Results: The cohort included 52 and 14 patients with and without ECRS, respectively. The number of total POU2F3-positive tuft cells (POU2F3+/H-PGDS+ and POU2F3+/H-PGDS-) was significantly higher in the ECRS group vs. the non-ECRS one (p < 0.0001). Moreover, the ratio of POU2F3-positive tuft cells expressing H-PGDS [POU2F3+/H-PGDS+/(POU2F3+/H-PGDS+ + POU2F3+/H-PGDS-)] was also significantly higher in the ECRS group vs. the non-ECRS one (p = 0.0084). Conclusions: These results suggest that tuft cells present in the context of ECRS may serve as a potential source of PGD2, thus involving to the amplification of type 2 inflammation.

OBJECTIVES:To describe the prevalence and clinical characteristics of headache or facial pain/pressure among patients presenting with rhinosinusitis in otolaryngology practice and to identify associated clinical findings. METHODS:We retrospectively reviewed 304 patients with rhinosinusitis at a tertiary otolaryngology center. Among these patients, headache or facial pain/pressure was assessed in 202 cases with available documentation and analyzed in relation to symptom severity, sinus computed tomography, and nasal endoscopic findings. Multivariable analysis identified factors independently associated with headache or facial pain/pressure. RESULTS:Among the 202 patients, 42.1% reported headache or facial pain/pressure considered related to sinonasal inflammation. High-intensity facial pain/pressure was uncommon, with 6.5% reporting high SNOT-22 scores. Active migraine at presentation was rare (1.0%), and a history of migraine (10.4%) was comparable to the general population. In multivariable analysis with false discovery rate adjustment, middle meatal polyps were associated with lower odds of headache or facial pain/pressure (OR: 0.41; 95% CI: 0.19-0.92; adjusted p = 0.032). A maxillary sinus Lund-Mackay score of 2 showed a positive association in unadjusted analysis (OR: 1.49; 95% CI: 1.08-2.04; p = 0.007) but was not significant after correction (adjusted p = 0.056). Headache or facial pain/pressure was not assessed in 102 of the 304 patients. CONCLUSION:Headache or facial pain/pressure is common but often mild in patients with rhinosinusitis in otolaryngology practice. Variability in symptom assessment may contribute to differences in reported prevalence, highlighting the importance of systematic inquiry combined with endoscopic and radiologic evaluation. LEVEL OF EVIDENCE: 3:

BackgroundSurgery is the standard treatment for oral cancer but often causes functional and cosmetic problems, and reoperation is difficult. Radiotherapy (RT) is less effective, with reirradiation limited by normal tissue tolerance and salvage surgery after RT carrying high complication risks. Systemic therapy is used for local recurrence but yields poor outcomes, underscoring the need for better options. Boron neutron capture therapy (BNCT) is an established method that selectively delivers high tumor doses. This study evaluated BNCT efficacy and safety in unresectable oral cancers not amenable to definitive RT.MethodsThis retrospective study included oral cancer patients treated with BNCT between June 2020 and June 2024 under the Japanese public health insurance system. Primary endpoints were best treatment response and incidence of adverse events (AEs), particularly severe oral mucositis (Grade ≥ 3 by Common Terminology Criteria for AEs version 5). Predictors of severe oral mucositis were also examined. Secondary endpoints included overall survival (OS), locoregional control (LRC), and progression free survival (PFS).ResultsAmong 74 patients (follow-up period ≥3 months), the majority (73%) had recurrent cancer. The complete response rate was 50%. The major severe acute AE was severe oral mucositis (all Grade 3) in 26% of patients. The maximum oral mucosal dose and the number of dental metals were significant predictors of severe oral mucositis. The 2-year OS, LRC, and PFS rates were 49%, 52%, and 29%, respectively.ConclusionThis study suggests that BNCT is an effective and safe treatment for unresectable oral cancers that cannot be definitively irradiated.

BACKGROUND:Due to the effects of NMBA administered during induction, intraoperative nerve monitoring may not respond properly during parotid gland surgery. OBJECTIVE:To investigate the relationship between NMBA administration during anesthesia induction and the time to recovery for intraoperative nerve monitoring in parotid gland surgery. MATERIALS AND METHODS:We retrospectively reviewed the medical records of 190 patients who underwent surgery for benign parotid tumors. We examined the factors associated with prolonged neuromuscular blockade. The correlation between NMBA dose per body weight and time to TOFC = 4 was also examined. RESULTS:The incidence of TOFC = 4 was 5.3% at 20 min, 33.2% at 40 min, 73.1% at 60 min, 91.6% at 80 min, and 96.3% at 100 min after NMBA administration. The time to TOFC = 4 was prolonged with a higher rocuronium dose per body weight, older age, and reduced renal function, each being an independent factor. A positive correlation was observed between NMBA dose and time to TOFC = 4. The administering rocuronium at 0.6 mg/kg during induction resulted in a TOFC = 4 time of 51.5 min. CONCLUSION:In parotid gland surgery, the effects of NMBAs used during induction may persist in some cases.

Warthin tumours (WT), the second most common benign salivary gland tumour, are histopathologically composed of bilayered oncocytic epithelial cells with occasional metaplastic epithelium. Tuft cells, which are chemosensory epithelial cells, are present in WT. Tuft cells serve various roles by producing physiologically active substances, such as prostaglandins (PGs). PGD2 released from tuft cells is crucial for tissue repair and inhibiting pancreatic carcinogenesis. However, whether or not tuft cells in WT produce PGD2 has not yet been elucidated. The present study aimed to investigate the production of PGD2 in POU class 2 homeobox 3 (POU2F3; a specific tuft cell marker)‑positive cells of WT and normal salivary glands. Consecutive patients with WT who underwent surgical resection were selected. Dual immunohistochemical staining for POU2F3 and haematopoietic PGD synthase (H‑PGDS) was performed. The present study included 28 patients with WT of the parotid gland (all male patients; median age, 68 years). The conventional bilayered oncocytic epithelium was present in all tumours; squamous metaplastic epithelium and conventional bilayered oncocytic epithelium were observed in 16 patients. Dual immunohistochemical analysis revealed that POU2F3+/H‑PGDS‑ cells were exclusively present in the striated duct of the normal salivary gland, and abundant POU2F3‑positive tuft cells were observed in both the conventional bilayered oncocytic and metaplastic squamous epithelia of WT. The median ratio of POU2F3‑positive cells expressing H‑PGDS was significantly higher in the conventional oncocytic epithelium (89.9%) than in the metaplastic squamous epithelium (10.6%) of WT (P=0.00044). The present results suggest a link between tissue injury to the striated duct and the pathogenesis of WT, and that PGD2 released from POU2F3‑positive cells in the conventional bilayered oncocytic epithelium is associated with ongoing tissue injury. Further studies are warranted to clarify the function of tuft cells in WT and gain deeper insights into the pathogenesis of WT.

The Practical Guideline for the Management of Allergic Rhinitis in Japan was first published in 1993. After the COVID-19 pandemic, the current 10th edition was published in 2024. The most recent collection of evidence from the literature, such as the sustained post-treatment effect of sublingual immunotherapy on Japanese cedar pollinosis, was added to the revised guideline, which incorporates evidence-based medicine. In this revised guideline, a diagram illustrating the pathogenesis of allergic rhinitis and the mechanisms of action of various pharmacological treatments has been added. Also included is a diagram that shows the mechanism of action of allergen immunotherapy and a more detailed description of the oral allergy syndrome. The clinical question and answer section was also revised along with the introduction of new questions, such as: Does anti-IgE antibody treatment effectively reduce the symptoms of severe seasonal allergic rhinitis? Also updated was the evidence-based step-by-step strategy for treatment.

Introduction: The goal of tracheostomy in patients with long-term tracheal intubation is to facilitate weaning from mechanical ventilation (MV), achieve decannulation, and ultimately enable discharge to home. In this study, we investigated the factors influencing withdrawal from MV after tracheostomy and cannulation in patients undergoing long-term tracheal intubation. We also examined tracheostomy status (whether the tracheostomy tube was removed and whether the patient was weaned from MV) and discharge outcomes. Methods: A total of 199 patients who underwent tracheostomy following long-term tracheal intubation were analyzed. Patients were classified into 3 groups based on tracheostomy status: group A (tracheostomy tube removed; n = 35); group B (tracheostomy tube not removed despite weaning from MV; n = 76); and group C (weaning from MV not achieved; n = 88). Results: The duration of intensive care unit stay did not differ significantly among the groups. However, hospital stay was significantly shorter in group C than in groups A and B. Additionally, the rate of discharge to home was significantly higher in group A. Factors associated with difficulty in weaning from MV included a blood lymphocyte count <500, the presence of chest and abdominal disease, and a body mass index >30. Factors contributing to with difficulty in decannulation after weaning from MV included head and neck disease, age >75 years, C-Reactive Protein >5, and a blood lymphocyte count <500. Conclusions: Weaning from MV and decannulation are key factors influencing discharge to home in patients undergoing tracheostomy after long-term intubation. These factors are primarily affected by the patient's underlying disease and general condition. We believe that addressing these factors through nutritional management, rehabilitation, and other supportive measures can improve the quality of life and increase the likelihood of discharge to home.

Parotid salivary duct carcinoma (SDC) is a rare and aggressive parotid gland carcinoma (PGC). SDC has two origins: de novo and ex pleomorphic adenoma (SDC ex PA); however, because of its rarity, the clinical and molecular features of the two types of SDC are not sufficiently understood. Here, we studied the differences in their clinicopathological and molecular features using clinical specimens while comparing them to those of adenoid cystic carcinoma (AdCC), an intermediate-grade PGC. Clinicopathological analysis of tissues from patients with PGC revealed significant associations between histological types and malignant phenotypes, including nodal metastasis, recurrence, vascular invasion, and neural invasion, and revealed more malignant phenotypes of de novo SDC than of SDC ex PA. The de novo SDC showed a significantly higher frequency of intra-neural invasion (intra-NI) and vascular invasion than AdCC and SDC ex PA. PGCs with high intra-NI were significantly correlated with malignant phenotypes and survival rates. Recently, we observed the overexpression of tropomyosin receptor kinase B (TRKB), a receptor tyrosine kinase, in PGC cells. Here, immunohistochemical and clinicopathological analyses showed that TRKB was highly expressed in SDC cells, particularly de novo SDC cells, and was significantly associated with poor survival and highly malignant phenotypes, including intra-NI and vascular invasion. Collectively, these data show that TRKB expression is significantly elevated in PGC, particularly in de novo SDC, and can be one of the biomarkers of their aggressiveness.

Objective: CD81, a transmembrane protein belonging to the tetraspanin family, has recently attracted attention as a therapeutic target for cancer owing to its important role in human cancer biology; however, there is no previous knowledge regarding CD81 expression in parotid cancer. Therefore, this study aimed to investigate CD81 expression in human parotid cancer and its involvement in cell proliferation. Methods: Tissue samples were collected from 36 patients with parotid cancer, including 10 with salivary duct carcinoma (SDC), 16 with mucoepidermoid carcinoma (MEC), five with adenoid cystic carcinoma (ACC), and five with carcinoma ex pleomorphic adenoma (Ca ex PA). CD81 expressions in the parotid cancer tissues were evaluated using western blotting and immunohistochemistry. Parotid cancer cell lines were established. The effect of suppressing CD81 expression by small interfering RNA (siRNA) and the effect of our anti-CD81 monoclonal antibody on the growth of parotid cancer cells were evaluated. Results: The immunohistochemical expressions of CD81 on tumor cell membranes were observed in the SDC and MEC tissues but not in the ACC and Ca ex PA tissues. Furthermore, inhibition of CD81 expression by siRNA suppressed the growth of parotid cancer cells, while the mouse monoclonal antibody against CD81 inhibited parotid cancer cell growth in a concentration -dependent manner. Conclusions: The expression of CD81 was observed in the SDC and MEC tissues. Proliferation of parotid cancer tissue -derived cells was suppressed by inhibition of CD81 expression.

We retrospectively analyzed the treatment results in 543 oral cancer patients who were admitted to our department between September 1999 and March 2023. The tongue was the most common primary subsite, followed by the gingiva and oral floor. Among the total of 543 cases of oral cancer, there were 132 clinical node-positive cases (24%). The overall 5-year disease-specific survival (DSS) rate was 71.8%, and the 5-year DSS rates in the stage I, II, III, and IV oral cancer cases were 91.5%, 81.2%, 62.1%, and 48.5% respectively. The 5-year DSS rates in the stage I, II, III, and IV tongue cancer cases were 91.4%, 80.6%, 59.5%, and 44.9%, respectively. The new N classification was more reliably associated with the survival as compared with previous N classifications in the tongue carcinoma cases. Among the 184 cases with T2 oral cancer, 77 (42%) were node-positive. An advanced T stage and a positive neck nodal status were significantly associated with poorer 5-year DSS rates.

Objectives: To investigate a method for predicting postoperative facial nerve palsy during parotid surgery using facial nerve monitoring. Design and setting: This was a prospective study of diagnostic tests performed from 2015 to 2018. Participants: We included adult patients who were underwent parotid surgery. Main outcome measure: We assessed prediction for postoperative facial nerve palsy by using intraoperative facial nerve monitoring, comparing between facial nerve trunk stimulation before and after tumor resection and between stimulation in the facial nerve trunk and each branch by using facial nerve monitoring. The amplitude response ratio (ARR) was calculated for the nerve trunk before/after surgery (ARR1) and for the trunk/periphery (ARR2). We compared these data in each group. In addition, we then examined the correlation between ARR and time to recovery of paralyzed branches. Results: A total of 113 patients were included. Among the 113 patients, 372 branches of 93 patients did not develop facial nerve palsy and were classified as group A. Among 20 patients who developed paralysis, 51 branches without paralysis were classified as group B, and 29 branches with paralysis were classified as group C. In patients with postoperative facial nerve palsy, the potential of the main stimulus was lower after removal than before removal. Similarly, the main trunk stimulation was lower than the peripheral stimulation after tumor extraction. When cut-off values for ARR1 and ARR2 were set to 0.63 and 0.55, respectively, the accuracy of postoperative facial nerve palsy diagnosis was 91.7% and 96.0%, respectively. Conclusion: Using FNM during parotid surgery enables easy prediction of postoperative facial nerve palsy.

Objective: Facial nerve paralysis due to parotid carcinoma is sometimes misdiagnosed as Bell's palsy. This study aimed to compare patients with parotid carcinoma with and without accompanying facial nerve paralysis and to capture the features of patients misdiagnosed with Bell's palsy. Methods: Among 209 patients, 42 (20%) had facial nerve paralysis. Of these 42 patients, 14 had received treatment for facial nerve paralysis without being diagnosed with parotid carcinoma (pretreatment group); the remaining 28 patients had not received any pretreatment and were diagnosed with parotid carcinoma at the initial visit to our hospital (no pretreatment group). This study compared patients with and without facial nerve paralysis and the pretreatment and no pretreatment groups. Results: The 42 patients with facial nerve paralysis had a significantly higher frequency of pain/tenderness and adhesion with surrounding tissues, significantly higher proportions of deep lobe tumors, and a significantly higher proportion of high-grade malignancy. In addition, the disease-specific and disease-free 5 year survival rates were significantly poorer in patients with than in those without facial nerve paralysis. The comparison between the pretreatment and no pretreatment groups revealed no significant differences in any factors nor survival rate. Five patients in the pretreatment group complained of palpable masses or pain/tenderness at the time of their initial treatment for paralysis. Conclusion: Patients with parotid carcinoma who present with facial nerve paralysis at the initial visit have a significantly poorer prognosis. The number of cases in the pretreatment group can be reduced by performing a detailed examination, which can potentially improve the prognosis.

We performed a retrospective analysis of the data of patients who underwent the initial operation for a benign parotid tumor in our department between September 1999 and March 2023. Data of a total of 1228 patients were analyzed. The most commonly diagnosed tumor was pleomorphic adenoma (764 patients), followed by Warthin tumor (257 patients). In regard to the tumor localization, superficial lobe tumors accounted for 56.7% of all tumors, deep lobe tumors for 19.6% of all tumors, and lower pole tumors for 23.7% of all tumors. Fine-needle aspiration cytology and frozen-section histopathological examination were used to identify the tumor histopathology. The overall rate of postoperative facial nerve palsy was 19%. A multivariate analysis was performed, which identified large-diameter tumors and deep-lobe tumors as the most important predictors of facial palsy. The postoperative facial palsy improved within 12 months of surgery in all cases, and there were no cases of permanent facial palsy. It is important to explain the risks of the postoperative complications to the patients so as to obtain appropriate informed consent from them for surgery.