With the widespread application of genetic testing in recent years, the pathogenesis of carotid body tumors has been clarified. At present, tumor resection is the only curative treatment, with the high risk of perioperative complications, such as intraoperative hemorrhage, inferior cerebral nerve dysfunction, and cerebral infarction. A multidisciplinary team approach is essential for planning safe surgical resection.

In addition, treatment options are limited for cases with unresectable disease, such as those with invasion of adjacent structures and/or distant metastasis. New treatment methods are developing. In the near future, new therapies targeting factors contributing to tumor development, such as SDHx, and tumor progression are expected to be developed.

Schwannomas are rarely seen in the nose and paranasal sinuses, and very rarely originate from the nasal septum. Moreover, a rapidly growing schwannoma suggests a possible malignant change, as these tumors are usually benign and slow-growing. Herein, we report a case of schwannoma originating from the nasal septum that rapidly increased in size. An 83-year-old female patient presented to our hospital with a 2-month history of nasal obstruction. CT revealed a soft tissue mass occupying the entire right nasal cavity. Histopathological examination of a biopsy specimen revealed that the tumor was a schwannoma. Both the patient and her family refused surgical intervention as she was elderly and also suffered from dementia. Therefore, we adopted a wait-and-watch approach. The patient subsequently complained of worsening nasal obstruction and the tumor was observed to have grown rapidly during the 1-year observation period. CT showed that the tumor had extended into the left nasal cavity and right ethmoidal sinus. Given the rapid enlargement within this short period of time, we again recommended surgery due to the possibility of malignant transformation of the tumor, and the patient and her family agreed to surgical intervention. Endoscopic sinus surgery was performed under the guidance of a navigation system. The origin of the tumor was located in the posterior portion of the nasal septum and we were able to remove the tumor completely. The resected tumor was diagnosed as a schwannoma based on positive immunohistochemical staining for anti-S-100 antibody. There was no evidence of malignant transformation, and the patient did not develop any tumor recurrence or metastasis after the surgery.

Dermoid cysts are rare lesions of the head and neck that usually present with few symptoms. Complete resection is the mainstay of treatment for dermoid cysts, however, airway management after surgery is essential, especially in children. We report the case of sublingual dermoid cyst arising from the floor of the mouth in a 6-year-old female child. CT/MRI images demonstrated a 50×40×30 mm cystic mass in the sublingual space. Fine-needle aspiration was performed under ultrasound guidance, and the findings were suggestive of a dermoid cyst in the floor of mouth. The cyst was surgically removed via a transoral approach. After the surgery, the patient was returned to the intensive care unit under tracheal intubation for safe airway management. After some days, she was extubated and the postoperative course was good. There was no evidence of recurrence during the 6-month follow up period. When encountering sublingual dermoid cysts arising from the floor of the mouth in a pediatric case, it is important to consider not only the appropriate surgical procedure, but also about postoperative airway management, even during the preoperative period.

Disorder of taste is classified into quantitative dysgeusia and qualitative dysgeusia. Zinc replacement treatment is usually the main treatment for taste disorder. However, serum zinc levels in patients with qualitative dysgeusia are often normal, and zinc replacement treatment is often ineffective in these patients. Therefore, other treatments such as antidepressants have been suggested for qualitative dysgeusia. Duloxetine is an antidepressant classified as a serotonin noradrenaline reuptake inhibitor (SNRI). We report 4 cases in which administration of duloxetine improved qualitative dysgeusia. SNRIs have antidepressant and analgesic effects. Glossodynia may be associated with qualitative dysgeusia. It has been reported that the analgesic effect of SNRIs may also be effective against glossodynia. SNRIs are considered as being a useful class of drugs for the treatment of qualitative dysgeusia.

We encountered two rare cases of plasmacytoma of the nasal cavity, which accounts for less than 0.5% of all malignant tumors in the head and neck region. According to the International Myeloma Working Group diagnostic criteria and classification (2014), both were classified as solitary plasmacytomas of the soft tissue.

A 35-year-old man was admitted to the hospital with the symptoms of common cold and was found to have a tumor on the left side of the nasal septum. It was a localized solitary lesion that was treated by resection and the patient showed no apparent signs of recurrence of the tumor for approximately 14 months. The other patient was a 73-year-old man was referred to our hospital by a doctor who pointed out that the patient had a tendency for erosion and swelling on the left upper turbinate mucosa. PET-CT revealed accumulation under the nasal cavity. Therefore, we elected radiation therapy, as surgical resection would have led to deformity of the nose. The tumor lesion could no longer be seen with the naked eye by about 2 months after the start of irradiation, but recurred about 7 months after the treatment. The patient is currently receiving chemotherapy under the supervision of a hematologist and is being followed up.

Multidisciplinary therapy is generally adopted for the treatment of solitary plasmacytoma of the soft tissue. Surgery alone, radiation therapy alone, or a combination of the two is often used for cases with localized resectable lesions. In regard to the 5-year survival rate, while it is only 10% in cases with multiple myeloma, it is 70% in patients with solitary plasmacytoma of the soft tissue. However, as in about a half of the cases, plasmacytomas either recur at the same or other sites, or progress to multiple myeloma, we would need to keep our patient under long-term follow-up at our department and the hematology department.

Most hemangiomas in the field of otolaryngology are vascular malformations, with venous malformations being the most common. We report a case of intramuscular venous malformation (IVM) of the masseter muscle which responded well to treatment with a Kampo medicine. The patient was a 22-year-old woman who presented with the complaint of swelling and pain in the left cheek. We diagnosed the patient as having an IVM in the left masseter muscle based on the findings of contrast-enhanced computed tomography, contrast-enhanced magnetic resonance imaging, and fine-needle aspiration biopsy. The patient refused the surgery as she was young and the IVM was not malignant. Therefore, we initiated the patient on a Kampo drug. In Kampo medicine, IVM are regarded as blood stasis, and typically, hemostatic agents are used for treatment. We chose keishibukuryogankayokuinin as the hemostatic agent. The size of the IVM reduced in response to the treatment, and the symptoms disappeared. It is important for patients to be offered the option of oral medication rather than surgery for IVM, where possible.

Hypercalcemia due to primary hyperparathyroidism sometimes triggers the development of fatal arrhythmias. Herein, we report a patient with parathyroid cancer, who developed cardiac arrest due to a fatal arrhythmia caused by hypercalcemia, in whom parathyroid surgery was performed after resuscitation and recovery.

A 62-year-old man lost consciousness when he stood up to make tea after dinner. His daughter performed a cardiac massage for him. After the ambulance crew arrived, they conducted defibrillation, administered adrenaline, and performed the maneuvers for cardiopulmonary resuscitation.

Laboratory investigation of the patient revealed hypercalcemia (14.8 mg/dL) and a high serum level of intact parathyroid hormone (PTH; 279 pg/mL), indicative of primary hyperparathyroidism. Cervical ultrasonography revealed a solid mass measuring 20×17×15 mm with unclear boundaries in the thyroid gland. ^99mTc-MIBI scintigraphy showed accumulation of ^99mTc-MIBI at the same site in the late phase. Paralysis of the right vocal cord was observed. Therefore, surgery was performed under the suspicion of parathyroid cancer.

During the operation, invasion of the recurrent laryngeal nerve was observed. Right thyroidectomy and parathyroidectomy were performed. Intraoperative examination confirmed that the patient’s serum intact PTH levels had decreased, and the operation was completed. Histopathology of the resected specimen revealed the diagnosis of parathyroid cancer. The postoperative course was good, and no local recurrence or distant metastasis was observed after 2 year.

We wish to reaffirm the risk of fetal arrhythmias caused by hypercalcemia and the need to recognize that the diagnosis of parathyroid carcinoma should be based on a combination of physical, laboratory, and imaging findings.

We encountered two patients who developed treatment-related myelodysplastic syndrome (MDS) and neck infection after chemoradiotherapy for head and neck squamous cell carcinoma (HNSCC), in whom we had difficulty in treating the neck infection and pharyngocutaneous fistula formation.

Case 1: 73-year-old male. The patient had undergone total pharyngo-laryngo-esophagectomy, bilateral neck dissection, and free jejunal flap reconstruction after neo-adjuvant chemotherapy (nedaplatin, 5-FU) 14 years earlier for left pyriform sinus squamous cell carcinoma (SCC) pT4aN2cM0. After surgery, he had received adjuvant chemoradiotherapy (docetaxel, 58 Gy) and adjuvant chemotherapy (oral fluorouracil agents). He was hospitalized thereafter due to necrosis of the free jejunal flap. After surgical debridement, a staged reconstruction strategy was considered for the defect. Reconstructions using a left deltopectoral (DP) flap, left pectoralis major myocutaneous flap, and right DP flap were attempted, but failed, with residual fistula formation due to marginal or total necrosis of the flaps. Finally, it took 67 weeks before we succeeded in closing the fistula using a migrating tube flap from the right DP flap. The patient was diagnosed as having MDS while he was hospitalized and this was thought to be responsible for his delayed wound healing.

Case 2: 76-year-old male. The patient had undergone neo-adjuvant chemotherapy (nedaplatin, S-1) and chemoradiotherapy (docetaxel, 60 Gy) 12 years earlier for left pyriform sinus SCC pT2N1M0. He had been diagnosed 3 years earlier as having MDS. He was hospitalized for deep neck infection. In spite of prompt surgical drainage and antibiotic therapy, he developed septic shock 7 weeks after admission. Although his condition began to improve and the fistula started to become smaller after the second surgery for debridement, his deep neck infection progressed to cervical vertebral osteomyelitis 30 weeks after admission and the patient died 39 weeks after admission.

In conclusion, physicians should be keenly aware that infection in a HNSCC patient who develops treatment-related MDS after chemoradiotherapy can be a life-threatening event, and close attention needs to be paid to wound healing in these patients.

Xanthogranulomatous tissue reaction, which is frequently mistaken for malignant tumor, is known to occur at many sites in the body, but is rarely seen in the salivary glands. Only 11 cases of xanthogranulomatous sialadenitis (XGS) have been reported in the literature. Herein, we report five cases of XGS and summarize the clinical features of these cases and also previously reported cases. Pain, which is the most common complication, was recorded in 11 cases. In general, benign parotid tumors are rarely painful, so we believe that the high frequency of pain in cases of XGS is one of the factors that make it difficult to distinguish it from malignant tumors. The onset site was the parotid gland in 14 cases, the submandibular gland in 1 case, and the sublingual gland in 1 case. No identifiable tumor was observed in 10 cases. Warthin’s tumor was identified in 5 cases, and mucoepidermoid carcinoma in 1 case. The most case of XGS, which was without malignant tumor, presented with facial nerve paralysis. Since it is difficult to confirm the diagnosis of XGS before surgery, rapid intraoperative diagnosis may allow appropriate and timely treatment to be undertaken. Pain, absence of malignant findings on FNA, and focal lesions with rim enhancement on dynamic magnetic resonance imaging may aid in the diagnosis.

Lymphoproliferative disorder (LPD) is classified as “other iatrogenic immunodeficiency-associated LPD” in patients receiving immunosuppressive drug therapy. For example, patients receiving methotrexate (MTX) who develop LPD are considered to have MTX-associated LPD (MTX-LPD). We report a case of MTX-LPD that required to be differentiated from parotid gland cancer.

The patient was a 69-year-old woman with rheumatoid arthritis who had been receiving MTX treatment for 8 years. She visited our department complaining of swelling and pain in the lower right ear and right facial paresis. We suspected the possible diagnosis of malignant lymphoma, cancer, or tuberculosis; however, no definitive diagnosis could be made by various tests. An open biopsy under general anesthesia was performed in preparation for total parotid gland resection, and rapid pathologic diagnosis revealed features consistent with LPD. We made a definitive diagnosis of MTX-LPD based on the medical history and permanent pathologic diagnosis. Six months after discontinuation of MTX, considerable improvement of the swelling and pain was observed, but the facial paralysis persisted. The clinical symptoms and imaging findings of this case were very similar to those of parotid gland cancer, however, it is noteworthy that we were able to avoid unnecessary surgery by considering the medical history to make a final diagnosis of MTX-LPD.

Otorhinolaryngologists need to be aware of the possibility of MTX-LPD manifesting in various parts of the head and neck, and confirmation of the histopathological diagnosis in a rapid and minimally invasive manner is important.

Fluorouracil (5-FU) is one of key therapeutic drugs for many solid tumors, including head and neck cancer. Pneumatosis intestinalis and portal venous gas, while being rare adverse effects of 5-FU administration, could prove fatal. Hyperammonemia is also one of the serious adverse effects of 5-FU. Herein, we report the case of a patient with hypopharyngeal cancer who developed both portal venous gas and hyperammonemia during 5-FU chemotherapy.

A 79-year-old man with a few months’ history of difficulty in swallowing was referred to our hospital. Upper gastrointestinal endoscopy and tissue biopsy revealed squamous cell carcinoma and the patient was diagnosed as having locally advanced hypopharyngeal cancer, cT4aN0M0. He was initiated on neoadjuvant chemotherapy with carboplatin (CBDCA) and 5-FU on day 1. On the day 3, he presented with consciousness disturbance and Kussmaul breathing. Upper gastrointestinal endoscopy revealed pneumatosis intestinalis under the gastric mucosa and abdominal computed tomography revealed portal venous gas. At the same time, blood test revealed hyperammonemia. As we considered these events to be serious adverse effects of 5-FU, we discontinued the 5-FU infusion and started the patient on treatment with antibiotics and a proton-pump inhibitor. The general condition of the patient gradually improved under careful observation, and the patient eventually showed complete recovery. In clinical settings, it is important to have a high index of suspicion for serious adverse effects of 5-FU, such as pneumatosis intestinalis, portal venous gas, and hyperammonemia.

A 52-year-old male patient with severe dental caries was hospitalized, initially for schizophrenia. However, he was administered antibiotic therapy with cefditoren pivoxil 300 mg/day for 1 day and ceftriaxone 2 g/day for 4 days for high fever (up to 39℃) and right facial swelling. He was transferred to our university hospital as his symptoms did not resolve. Computed-tomographic examination revealed cellulitis and abscess formation around the right infratemporal space. On day 1 of hospitalization, drainage via both lateral temporal and submandibular approaches and right palatine tonsillectomy were performed under general anesthesia, followed by initiation of antibacterial treatment (meropenem 2 g/day for 9 days, ampicillin/sulbactam 6 g/day for 11 days and garenoxacin 800 mg/day for 7 days). On day 5, repeat drainage was needed, which was performed via an oral approach, through the right tonsillar bed, under local anesthesia. The abscess showed complete resolution after 34 days. Prevotella oralis and Streptococcus constellatus were isolated by bacterial culture of the purulent discharge specimen obtained from the abscess.

It is important to recognize that severe caries of the mandibular teeth can cause an abscess in the infratemporal spaces. Immediate surgical drainage and antibacterial treatment covering anaerobic bacteria, were critical for the treatment of the extensive abscess.

We report a case of true superficial temporal artery aneurysm in the anterior ear. A 71-year-old woman visited a clinic with a 10-year history of a gradually enlarging mass in the anterior part of the right ear, and was referred to our hospital. She was found to have a 10×10 mm dome-shaped elastic-soft pulsatile mass in the anterior part of the right ear and was diagnosed as having a right superficial temporal artery aneurysm by doppler ultrasonography. CT angiography showed a mass that was contiguous with the superficial temporary artery. Under general anesthesia, we performed ligated the temporal artery and resected the aneurysm. Because the aneurysm had a three-layer structure of intima, media, and adventitia, we diagnosed it as a true right superficial temporal aneurysm. A true aneurysm is often associated with arteriosclerosis caused by hypertension, hyperlipidemia and diabetes mellitus, and our patient had all of these diseases. There are reports of untreated superficial temporal artery rupture, reports of collaterals of intracranial arteries and ophthalmic arteries, and reports of aneurysms at other sites, including the intracranial area. Although a superficial temporal artery aneurysm in the anterior ear is rare, it is necessary to make a precise diagnose for appropriate and timely treatment.