Sound travels from the cochlea through the cochlear nucleus, superior olivary nucleus, inferior colliculus, and medial geniculate body of the thalamus, via the acoustic radiation, to the primary auditory cortex located in the superior temporal gyrus (Broadmann Area BA 22) and transverse temporal gyrus (Heschl’s gyrus, BA 41, 42) of the temporal lobe. The spatial arrangement (tonotopic organization: spatial arrangement in descending order of frequency) according to the characteristic frequency of cochlear neurons is reproduced in each pathway. Basic auditory information processing is thought to be performed up to the inferior colliculus, and the medial geniculate body is thought to act as a gate for selecting the information to be sent to the auditory cortex.

In auditory information processing, similar to the visual system, there are dorsal and ventral nerve tracts from the auditory cortex to the temporal lobe and prefrontal area, and the dorsal route is reportedly responsible for sound localization related to the “Where,” and the ventral route is responsible for sound source identification related to the “What” in sound recognition. For the language function, both the dorsal and ventral pathways are involved, but play different roles. The dorsal pathway plays an important role in higher-order language functions, focusing on the grammar, and the ventral pathway is involved in the understanding of the meaning of sentences. Analyses of intonation in spoken language occur in the superior temporal gyrus adjacent to the outer part of Heschl’s gyrus, and the process of speech recognition is expected to involve not only recognition of the speaker’s words and grammar, but also of intonation in an independent process. Changes in the activities of the left inferior frontal gyrus, left lateral temporal gyrus, and superior temporal gyrus were observed when the subjects were listening to spoken language in a noisy environment, suggesting that words that are indistinct due to noise are restored by Top-Down input. Moreover, the promotion of anticipation of events caused by the activity of the orbitofrontal cortex may be involved in the improvement of hearing.

COVID-19 pneumonia is a respiratory disease mainly manifesting with the symptoms of fever, cough and malaise. While the condition is mild and improves spontaneously in about 80% of patients, some patients need mechanical ventilation or extracorporeal membrane oxygenation (ECMO). Some patients present to the department of otolaryngology because of olfactory disturbance during the course of the disease. It is often difficult to differentiate the disease from other diseases due to the absence of fever. Herein, we report the case of a patient who was referred to our department as a suspected case of chronic sinusitis after several medical examinations, and was subsequently confirmed as having COVID-19 pneumonia. Although the otolaryngologist was not aware that the patient had COVID-19 pneumonia at the time of examination, appropriate infection prevention measures, including wearing of an N95 mask, were taken to reduce the risk of infection of the staff in this case.

It is expected that otolaryngologists will examine more and more COVID-19 patients without typical symptoms. In order to prevent infection among the medical staff, it is important to carefully interview each case and take appropriate precautions.

Inflammatory pseudotumor is a benign disease that is histopathologically characterized by the presence of non-specific chronic inflammatory cells. Clinically, these tumors often show neoplastic growth, and it is difficult to differentiate them from neoplastic lesions by imaging findings alone. Inflammatory pseudotumors have been found to occur at various sites, but are rarely found in the head and neck region. Although surgical excision and steroid therapy are effective, no evidence has been established yet. We report a case of an inflammatory pseudotumor that occurred in the cheeks.

A 51-year-old man with right cheek swelling and pain had visited a local physician a month earlier and antibiotics had been prescribed. Since the symptoms did not improve, CT was performed as an aid to diagnosis, and an abscess or neoplastic lesion was suspected in the cheek. Cytologic examination revealed many neutrophils and histiocytes, but no evidence of malignancy. MRI showed an abscess in the masseter muscle with spread of the inflammation to the surrounding tissues. Antibiotics and steroid therapy were initiated and the swelling diminished in size. When the steroid was withdrawn, the swelling enlarged again. Therefore, inflammatory pseudotumor, non-epithelial tumor, and malignant lymphoma were considered in the differential diagnosis. An excisional biopsy was performed and the diagnosis of inflammatory pseudotumor was established. A subset of the cells was positive for IgG4, but there was no definitive evidence of IgG4-related diseases.

Treatment of inflammatory pseudotumors includes surgical resection, steroid therapy, radiation therapy, chemotherapy; the efficacy of steroid therapy has been reported for inflammatory pseudotumors in the head and neck region. Although evidence has still not been established, steroid maintenance therapy is effective for preventing recurrence. The patient is currently receiving steroid maintenance therapy on an outpatient basis, and has shown no evidence of recurrence of the inflammatory pseudotumor.

External dental fistula is associated with the formation of a sinus tract as the route of excretion of chronic purulent inflammatory material, that pierces the jawbone and creates a fistula in the skin of the face or neck, often away from the teeth. The patient was a 68-year-old woman, who presented to our department with mass in the left lower jaw. We recognized a 30 mm mass in the left lower jaw. Based on the findings of ultrasonography and fine-needle aspiration biopsy, the mass was suspected as an inflammatory tumor, and the patient was followed up. However, the amount of granulation increased and the surrounding skin was depressed. The diagnosis of external dental fistula was suspected from the findings of pantomography and magnetic resonance imaging, and fistula extraction, tooth extraction and curettage was performed as long as 2 years and 2 months after the initial medical examination. The postoperative course was favorable and there has been no recurrence. Early diagnosis and appropriate treatment are of importance in patients with an external dental fistula.

Secretory carcinoma (SC) is a low-grade salivary gland carcinoma similar to secretory breast carcinoma harboring the ETV6-NTRK3 fusion gene, that was first proposed as a distinct disease entity in 2010 by Skálová et al. SC has heterogeneous histopathological manifestations, so that definitive diagnosis of the tumor by histopathological examination is difficult. Many fusion partners of ETV6 are known in other malignant tumors. In the case of SC also, previously unknown fusion partners of ETV6 (ETV6-X) have been reported recently. Herein, we report a case of SC of the submandibular gland harboring an ETV6-X fusion gene. A 32-year-old man presented to our department with a mass in his right submandibular region that he had first noticed one month earlier. We diagnosed the mass as a submandibular gland tumor and performed submandibular gland excision. The postoperative histopathological findings led to suspicion of the tumor as a SC. Subsequently, FISH analysis led to a confirmed the diagnosis of SC with an ETV6-X fusion gene. No evidence of recurrence was noted during postoperative follow-up of the patient for 20 months without any further therapy. Because of the difficulty in the histological diagnosis and absence of any availability of established treatments for tumors harboring the NTRK family genes, it is important to perform genetic examination for confirmatory diagnosis in patients with suspected SC.

Intravascular papillary endothelial hyperplasia (IPEH) is a benign vascular proliferative condition characterized by papillary proliferation of endothelial cells within the vascular lumen. IPEH generally occurs after trauma, and cases in the lip and tongue are frequently reported in the head and neck region. We report a case of IPEH in the masseter muscle.

The patient was a 26-year-old woman, who was referred to our department with the chief complaint of pain on pressure in the right buccal region. At the first examination, a buccal mass measuring about 1 cm in size was palpable on the right side. Ultrasonography revealed the presence of a hypoechoic mass with weak arteriovenous blood flow within the mass. T2-weighted MR imaging revealed a high-intensity area in the right masseter muscle. Hemangioma was suspected, and surgical removal was performed under general anesthesia. Histopathological examination of the resected specimen revealed the diagnosis of IPEH. Endothelial cells on the surface of the papillary structure were positive for anti-CD31 antibody, anti-CD34 antibody, and factor VIII, which are vascular endothelial markers, confirming the diagnosis. IPEH is clinically difficult to distinguish from hemangiomas and angiosarcomas, and the diagnosis can often be established only by histopathology. Total mass resection should be performed if a mass lesion in the masseter muscle is suspected as a hemangioma.

Pyogenic granuloma is a blood-rich mass occurring in the oral and nasal cavity, that is often seen in pregnant women. This mass often grows to a large size before any symptoms become manifest. We present a case of laryngeal pyogenic granuloma in a 29-year-old pregnant woman. She presented with a history of pharyngeal discomfort and hoarseness from the 27th week of pregnancy. Fiberoptic laryngoscopy revealed a mass located in the left vocal cord that occupied about one-third of the glottic space. The patient did not complain of breathlessness at the first consultation, but developed dyspnea about five hours after the first consultation. A fiberoptic laryngoscopic examination revealed an increase in the size of the mass, which was now occupying two-thirds of the glottic space. Tracheostomy was performed under local anesthesia. Five days after the tracheostomy, under local anesthesia, we removed the mass with a snare under fiberoptic laryngoscopic guidance. The histological findings revealed the diagnosis of pyogenic granuloma. The patient has been followed up for one year, with no evidence of recurrence. We considered that laryngeal pyogenic granuloma could obstruct the airway rapidly, so that close attention should be paid to any respiratory symptoms.

Introduction: Large malignant lymphomas of the thyroid (hereafter, thyroid malignant lymphomas) can cause airway obstruction. Therefore, we studied the airway problems in patients with thyroid malignant lymphomas diagnosed at our hospital.

Method: We conducted retrospective analyses of the data of 41 patients who were diagnosed as having thyroid malignant lymphoma between January 2013 and December 2019 at our hospital. Patients were classified into three groups (an emergent intubation group, an emergent steroid treatment group, and a normal treatment group). Statistical analyses were performed to compare the symptoms, tracheal diameters, pathological diagnosis, and soluble interleukin-2 receptor (sIL-2R) levels among the groups.

Results: There was a tendency towards emergent treatment being needed more often in patients presenting with dyspnea, dysphagia, or vocal cord paralysis, and in patients with high malignant grade lymphomas or high serum levels of sIL-2R.

Conclusion: Emergent treatment was more often required in patients with dyspnea, dysphagia, or vocal cord paralysis, and in patients with high serum levels of sIL-2R. Administration of steroid treatment after thyroid biopsy performed under local anesthesia, and prompt diagnosis of lymphoma by the flow cytometry method were effective for reducing the airway obstruction. However, as airway obstruction is an emergency, intubation or tracheostomy should be performed without hesitation where needed. In the case of a difficult airway intubation, extracorporeal membrane oxygenation may need to be considered.

We retrospectively studied the postoperative complications in patients with laryngeal/hypopharyngeal cancers who underwent salvage surgery at our department during the 14-year period between 2005 and 2019.

The salvage group consisted of 34 patients, including 31 men and 3 women with an average of 70.3 years (48–89 years): They had received (chemo)radiotherapy as the first-line treatment, followed by salvage surgery because of recurrent or residual tumor. Of the 34 patients, 22 and 12 patients had laryngeal and hypopharyngeal cancers, respectively, and 26 and 8 patients had been treated by total laryngectomy and total pharyngolaryngoesophagectomy, respectively. The control group consisted of 93 patients, including 92 men and 1 woman, with an average of 69.0 years (51–94 years): They had undergone radical surgery as the first-line treatment. Of the 93 patients of this group, 47 and 46 patients had laryngeal and hypopharyngeal cancers, respectively, and 51 and 42 patients had been treated by total laryngectomy and total pharyngolaryngoesophagectomy, respectively.

Overall, a total of 29 patients developed postoperative complications, including wound dehiscence, necrosis of transplanted grafts, wound infection/ulcer/abscess, and thrombosis of anastomosed vessels. The incidence of all complications was higher in the salvage group than in the control group (35.3% vs. 18.3%, P=0.022). The incidence of moderate/severe complications was also higher in the salvage group than in the control group (32.4% vs. 11.8%, P=0.003). Patients with a poor preoperative nutritional status showed a higher incidence of moderate/severe complications than those with a good nutritional status (30.0% vs. 13.4%, P=0.018). This tendency was more noticeable in the salvage group; the incidence of moderate/severe complications in patients with a poor nutritional status of this group was as high as 60.0%, whereas that in the patients with a good nutritional status was only 20.8% (P=0.013).

These results indicate that preoperative (chemo)radiotherapy and a poor nutritional status are risk factors for postoperative complications after salvage surgery in patients with laryngeal/hypopharyngeal cancers. Preoperative nutritional intervention may be one of the effective measures to prevent complications after salvage surgery in these patients.

Adenoid cystic carcinoma (ACC) accounts for approximately 1% of all cases of head and neck carcinoma, and ACC of the jaw has rarely been reported. Herein, we report a case of ACC of the mandible which responded well to radiation therapy alone.

An 85-year-old woman presented to us with swelling of the mandible and hypoesthesia extending from the lower lip to the chin. Computed tomography (CT) revealed destruction of the entire mandibular bone. Biopsy of the mandible revealed ACC with a cribriform pattern. Whole-body examination revealed metastasis to the clavicle, sternum, rib, and iliac bone. Considering the patient’s age and her wishes, we selected palliative care, namely, radiation therapy alone, with short-term hospital admission.

After the treatment, the FGD accumulation in the mandible could no longer be seen on positron emission tomography-computed tomography (PET-CT), and the destruction of the mandible had improved.

Usually, patients with ACC are treated by surgery and postoperative chemotherapy. Radiotherapy alone is selected for patients with advanced disease or on account of the less favorable background factors of the patients. The reported 5-year local control rate in response to radiotherapy alone is about 50%, and the treatment was effective in this case.