Laryngeal stroboscopy and high-speed digital imaging (HSDI) are used for clinical examinations and research concerning vocal cord vibrations. Laryngeal stroboscopy is already widely used in daily clinical practice; however, while HSDI has been studied extensively, it is rarely used for routine outpatient clinical practice. The goal of this paper is to describe two ways in which we use laryngeal HSDI in daily clinical practice: to choose the injection site in injection laryngoplasty and in the diagnosis of sclerotic lesions on the vocal cords. We usually select injection sites based on information derived from the video recorded by HSDI just before the procedure. For the evaluation of vocal fold sclerotic lesions, a lack of vibration and decrease in wave motion can be observed more accurately using HSDI than with stroboscopy. Therefore, HSDI is useful for the diagnosis of vocal fold sclerotic lesions. HSDI is useful not only for making a diagnosis before treatment but also for performing evaluations after treatment and assessing recurrence. In this paper, we described how we use HSDI in our daily clinical practice.

Human papilloma virus (HPV) infection often only forms asymptomatic or benign papillomas, but in some types, it causes malignant tumors. Among cases of laryngeal tumor, HPV is detected in more than 90% of laryngeal papillomas and is related to the onset. In our department, HPV infection was found in 95% of cases, all of which were low-risk type (types 6 and 11). Laryngeal papillomas are typically treated by surgery, but in cases of multiple relapse, a cure can be difficult to achieve with surgical treatment alone. Given that HPV infection is a viral disease, it is important for surgical treatment to reduce the tumor volume, disease extent, and viral load as well as to prevent as much normal tissue as possible from being injured. Adjuvant therapy after surgery is important for the prevention of recurrence, but effective adjuvant therapy is not yet available for all cases, so the development of a suitable adjuvant therapy is necessary. Since HPV is related to the onset of head and neck cancer, especially oropharyngeal cancer, the prognosis differs depending on the presence or absence of HPV infection. In the case of oropharyngeal carcinoma, the 2018 version of the head and neck clinical practice guidelines was revised to include staging with or without HPV infection. The involvement of HPV in laryngeal cancer also needs to be considered. Laryngeal cancer patients had HPV infection in 18% of cases, with type 16 viruses accounting for 81% of these cases. HPV-related laryngeal carcinoma, which seems to be actually involved in carcinogenesis, is relatively infrequent (2.3% of cases). In laryngeal cancer, the possibility of HPV alone being an oncogenic factor is low, suggesting that this is a tumor involving multiple factors, such as smoking and drinking.

1. Phonosurgery is performed on the human larynx to treat phonatory dysfunction and improve the quality of voice.

2 . There are two major categories of phonosurgery. One surgical option is open-neck laryngeal surgery, which is performed via an extralaryngeal approach. The other is endolaryngeal microsurgery and endoscopic surgery, which are performed via an intralaryngeal approach.

3. When performing phonosurgery via an extralaryngeal approach, it is very important to be able to visualize the internal laryngeal structures by looking at the laryngeal cartilage. Furthermore, when performing phonosurgery via an intralaryngeal approach, it is important to be able to visualize the internal laryngeal structures, including histoanatomy, by observing the mucosa of the lumen. An understanding of the histologic structures of the vocal fold is also essential when performing phonosurgery.

4. Knowledge of the three-dimensional structure, histology and histopathology of the larynx is indispensable when performing phonosurgery.

Voice therapy consists of vocal hygiene training to prevent certain voice problems and vocal modification training to encourage appropriate vocalization. The voice therapy regimen depends on the pathological condition of vocalization (laryngeal hyper and hypofunction, incomplete glottic closure).

During vocal hygiene training, patients are required to understand the mechanism of vocalization and factors known to exacerbate voice disorder, and hygiene training must be presented to each patient individually to ensure the best outcome.

The goal of vocal modification training is to improve the vocal efficiency by adjusting the collision intensity of the vocal folds. In this paper, the author describes voice therapy based on several points to improve the utility of intrinsic laryngeal muscles (lateral cricoarytenoid muscle, thyroarytenoid muscle, and cricothyroid muscle).

Transoral surgery is gaining importance as a minimally invasive treatment for laryngeal and pharyngeal cancer. We invented an original surgical technique of transoral videolaryngoscopic surgery (TOVS) using a distending laryngoscope, semi-rigid videolaryngoscope and 3-mm-diameter surgical forceps. Malleable devices have recently been introduced (grasping forceps, needle cautery, suction coagulator and Laser fiber) to facilitate approaching the marginal area of the endoscopic view. The benefits of this surgical system include a wide surgical view on the monitor, bimanual manipulation, en bloc resection, tactile sensation and cost effectiveness. The indications of TOVS are oropharyngeal, hypopharyngeal and supraglottic cancer with Tis, T1, T2 and selected T3 status. Selected radiorecurrent cancers （rT1 and rT2 lesion) are also included. Resectable nodal involvement can be managed by combination with neck dissection. Regarding the results of whole cases, the 5-year overall survival, disease-specific survival, local control rate and laryngeal preservation rate (hypopharyngeal and supraglottic cancer) were 80.6%, 88.4%, 90.4% and 94.8%, respectively. Postoperative radiotherapy or chemoradiotherapy was performed in 30% of cases. Surgical complications included emergency tracheostomy (2.3%), laryngeal edema managed by medical treatment (2.7%), bleeding (3.2%) and wound healing problems (2.7%). Regarding the post radiation status, any observed wound healing problems should be carefully managed. Chronic dysphagia (FOSS more than 3) occurred in 5.5% of cases. Arytenoid resection, a wide resection area and an older patient age are the risk factors for postoperative swallowing problems.

To clarify the clinical manifestation and differential diagnosis of spasmodic dysphonia, the recent literature is reviewed with special regard to “Diagnostic Criteria and Severity Classification for Spasmodic Dysphonia,” which was recently published by a research group using a Health and Labor Sciences Research Grant. Spasmodic dysphonia is a focal movement disorder of the larynx. The main symptom of spasmodic dysphonia is intermittent abnormality of phonation mixed with normal voice production during speech. The voice property is represented as strangulation, interruption, tremor or roughness in adductor type and breathiness, aphonia or flutter in abductor type. The symptoms of spasmodic dysphonia are well explained as an expression of focal dystonia of the larynx. Differential diagnoses should be made from dysphonia of other functional, psychosomatic and neurological origins. Precise history taking, a psychoacoustic evaluation and an acoustic analysis of the speech using symptom-inducing tasks and endoscopic observation during speech are mandatory. Diagnostic intervention with voice therapy or botulinum toxin injection into the internal laryngeal muscles is helpful for managing difficult cases.

Instances of dyspnea and mammal disorder due to pharyngeal stenosis and laryngeal stenosis should be carefully examined, and the cause and most effective treatment must be determined in order to ensure the patient’s survival and proper development. Tracheostomy is the most reliable method of ensuring breathing in cases of occlusion of the upper airway, but wearing a tracheal cannula can disturb the lives of children who attend school. However, if tracheostomy is not performed, then these children cannot achieve mobility and proceed with rehabilitation. We should therefore consider the best treatment to ensure children’s quality of life, including approaches through the nasopharyngeal airway and/or surgical intervention.

Three cases of laryngeal spindle cell carcinoma（SpCC）were reported in this study. All cases had hoarseness as the chief complaint and were treated by surgery and irradiation.

Case 1 was a 69-year-old male with a polypoid mass on the glottis. He underwent a biopsy by general anesthesia, and the histopathological diagnosis was SpCC. Total laryngectomy was performed. Case 2 was a 70-year-old male with a granulomatous mass on the left vocal cord. The histopathological diagnosis was SpCC. Radiotherapy was performed. Case 3 was an 85-year-old male with dementia with a polypoid mass on the left vocal cord. Cordectomy was performed. No recurrence has been seen in over 12 months since the initial treatment in all cases.

Imaging findings of laryngeal cyst are generally specific. We herein report a case of laryngeal cyst in which a diagnosis was difficult. The patient was a 66-year-old man experiencing pharyngeal paresthesia. He was referred to our hospital because laryngeal tumor on the right arytenoid was suspected. Computed tomography and magnetic resonance imaging showed the presence of solid tumor 5cm in diameter in the laryngeal cavity. We performed tracheotomy to prevent airway stenosis and a biopsy via an oral approach. The mass was covered with a smooth mucous membrane, so we made an incision at the membrane and resected the lesion partially. The specimen was not malignant, but we were unable to make any further diagnosis. To confirm the diagnosis and determine the treatment approach, we performed surgery via an external approach. After making an incision at the right thyropharyngeal muscle, we discovered the mass inside the thyroid cartilage. The mass had no adhesion to the surrounding organs and was able to be removed. A histological examination of the resected mass showed degeneration of a cystic lesion with an inflamed capsule.

To investigate the prognostic significance of pretreatment inflammatory biomarkers in patients with advanced hypopharyngeal cancer (HPC), 88 patients with Stage IV HPC treated with radiotherapy (RT), chemoradiotherapy (CRT) , or bioradiotherapy (BRT) were enrolled and the impact of pretreatment inflammatory biomarkers including fibrinogen, the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR) and the lymphocyte-to-monocyte ratio (LMR) on the survival of these patients was evaluated. These markers were categorized into two groups according to the results of receiver-operating characteristic plots for determining of the cut-off value. In the present study, NLR ≥3.59 was associated with a poor overall survival (OS) and progression-free survival (PFS) in patients with advanced HPC. In addition, our multivariate analysis showed that an NLR ≥3.59 was an independent prognostic factor for the OS and PFS. These results suggested that the NLR was a useful pretreatment biomarker for identifying advanced HPC patients likely to have a poor outcome.

Objective : To study the efficacy of laterofixation for bilateral vocal fold immobility （BVFI） in adduction.

Study design and Methods : We retrospectively analyzed the outcomes of laterofixation as the initial surgery for tracheostoma closure in nine patients who underwent tracheostomy for airway narrowing due to BVFI in adduction at Toho University Omori Medical Center from 2007 to 2016 and an additional patient who underwent surgery at Yokohama City University Hospital in 2017. The study examined the possible causes of BVFI in each subject, the endoscopic findings of the posterior glottis and subglottis, the results of electromyographic examinations and the intraoperative traction and mobility tests. Results : Based on the results of examinations, the 10 cases were classified into 2 groups: 4 with bilateral vocal fold palsy （BVFP） and 6 with posterior glottic stenosis （PGS）. Successful tracheostoma closure by laterofixation was achieved in all of the BVFP patients but in only two of the PGS patients. Conclusions : Laterofixation is a simple operation that can be performed at any facilities performing direct laryngoscopy. However, the efficacy of the operation appears to be limited, particularly in cases retaining laryngeal muscle tonus, such as in PGS patients.

Primary subglottic cancer is a very rare condition. In almost cases, a delayed diagnosis of subglottic cancer is made in patients complaining of hoarseness or dyspnea. This often leads to a poor prognosis. The subglottic tumor spreads to invade deep structures, including the muscles or interstitial tissue. We reported four cases of subglottic cancer that were observed from 1986 to 2008. This number constitutes 1.0% of all the laryngeal cancers that were observed during this period. Three cases were treated with total laryngectomy with neck dissection. The remaining case was treated with radiotherapy alone. The overall five-year- survival rate was 75%. In two cases, horizontal serial pathological sections showed tumor invasion to thyro-arythenoid muscle （Case 1）and invasion of the thyroid cartilage across the anterior commissure of the larynx （Case 2）. We stressed the necessity of total laryngectomy with hemi-thyroidectomy and unilateral neck dissection including dissection of the paratracheal lymph node, as the treatment for subglottic cancer according to the characterization of its pattern of spread.

Spontaneous regression of a malignant tumor is rare, and that of laryngeal cancer is extremely rare. We herein report a case of laryngeal cancer with spontaneous regression.

A 43-year-old man presented to our hospital with a four-week history of hoarseness. An endoscopic examination revealed an irregular tumor in his left vocal cord. After an endoscopic biopsy and computed tomography, he was diagnosed with laryngeal squamous cell carcinoma (cT1aN0M0). Before starting radiation therapy, his hoarseness improved, and the cancer disappeared without any treatment. The clinical course was uneventful, and there has been no recurrence in the 30 months since his first visit.

It is speculated that the endoscopic biopsy may have triggered the spontaneous regression of his laryngeal cancer, although the associated mechanism is unclear.