Robotic surgery is ushering in a new era in surgery by offering patients better outcomes and has already become one of the standard modalities in urology and gynecology. In the head and neck field, after the FDA clearance in 2009, transoral robotic surgery (TORS) has now been widely adopted by head and neck surgeons for treatment of benign and malignant conditions of the pharynx and larynx. Another use of surgical robots in the head and neck is thyroidectomy and neck surgery. Robotic thyroidectomy has been developed mainly by Korean surgeons and the technique has evolved into robotic neck dissection. In Japan, multi-institutional clinical study of TORS using da Vinci Surgical System had been conducted and PMDA clearance was obtained in 2018. Japan Society for Head and Neck Surgery has announced recommendations and credentials for head and neck robotic surgery in January 2019 and advance course for TORS has been held every month in Fujita Health University since May. Recent progress of surgical robots and future directions of robots and surgery in the head and neck are also discussed.

In this report, we describe a clinical case of a schwannoma arising in the external auditory canal. A 45-year-old woman with a pituitary adenoma who was being followed up presented to our department with a mass in the external auditory canal detected using computed tomography (CT). Physical examination revealed a dull red and soft mass arising from the inferior and anterior wall of the right external auditory canal. There was no tenderness. CT images of the temporal bone demonstrated a well-circumscribed, soft tissue mass narrowing most of the external auditory canal. There was no bone erosion and no middle ear or mastoid involvement. A biopsy was performed before surgery, and she was diagnosed as having a myxoma. The patient underwent excisional surgery through a transmeatal approach under general anesthesia.

Histopathologic examination revealed areas of compact spindle cells arranged in short bundles. The tumor cells were composed of Antoni-A and Antoni-B areas. Immunohistochemical staining demonstrated positive staining of tumor cells for S-100. The final diagnosis was a schwannoma of the external auditory canal. Nine months postoperatively, there were no signs of local recurrence in the external auditory canal. In this case, the tumor arose from the interior and anterior wall of the right external auditory canal and was derived from the auriculotemporal nerve. Based on a careful review of the literature, we found 18 cases of schwannomas originating in the external auditory canal. In these reports, four cases were derived from the auriculotemporal nerve and seven cases were derived from the auricular branch of the vagus nerve (Arnold nerve). The treatment of benign tumors in the external auditory canal is excision with safety margins. If the tumor is large or the base of the tumor is wide or deep, a post-aural approach is better.

Herein, I report a case of a temporomandibular joint herniation. A 77-year-old male patient presented with the complaint of developing tinnitus in his left ear when he bit into foods. On examination, I confirmed projection of the anterior wall of the external auditory canal during biting, with the projection retracting when the patient opened his mouth. Computed tomographic examination revealed a partial defect of the anterior wall of the bony external ear canal. I thought that this defect was caused by failure of the foramen of Huschke to close during development. The projecting anterior wall of the external auditory canal pressed on the eardrum, causing tinnitus of the left ear. This case underscores the need to bear in mind temporomandibular joint herniation as a cause of tinnitus.

Hamartoma of the larynx is an extremely rare disease. Because of the location of the tumor, it may manifest with severe symptoms, including upper airway obstruction. Urgent otolaryngologic evaluation and early treatment are needed.

Herein, we report a case of hamartoma in an infant, manifesting with stridor. Because the hamartoma was located in the epiglottis and entered the tracheal orifice during respiration, we removed it surgically via the intraoral approach. At present, 3 months since the surgery, the patient is doing well, without any respiratory symptoms. Even though this tumor is not malignant, careful follow-up is needed, because of the possibility of recurrence.

Primary sebaceous carcinoma of the head and neck region is extremely rare. Herein, we report a case of sebaceous carcinoma of the external auditory canal. A 66-year-old man presented with a feeling of ear fullness and a mass in the right external auditory canal. An incisional biopsy was performed and the histopathological diagnosis was malignancy, either basal cell adenocarcinoma or sebaceous carcinoma. The patient was treated by lateral temporal bone resection without any complications. The final diagnosis based on histopathological examination of the resected specimen was sebaceous carcinoma of the external auditory canal. At 21 months after the surgery, the patient was alive, with no evidence of tumor recurrence or metastasis.

We encountered 6 patients with stage T1 or T2 carcinoma of the external auditory canal. All patients underwent treatment, including by lateral temporal bone resection. One patient died of the disease with local/distant metastases and another died of an unrelated disease, however, the remaining 4 patients were alive without any evidence of recurrence until the last follow-up. This result revealed that lateral temporal bone resection is a good treatment option for stage T1 and T2 carcinoma of the external auditory canal.

Carcinoma of the external auditory canal is a rare disease entity, accounting for less than 0.2% of all head and neck cancers. We retrospectively analyzed the clinical characteristics and treatment outcomes of patients with this disease.

The patients were 23 newly diagnosed cases of carcinoma of the external auditory canal who were treated in our department between 2005 and 2018. They consisted of 11 males and 12 females, aged 41 to 93 years with an average of 69.4 years. The tumor stage at diagnosis was T1 in 13 patients, T2 in 4 patients, T3 in 1 patient and T4 in 5 patients. The histopathological type was squamous cell carcinoma in 19 patients (82.6%). Eighteen patients underwent radical surgery, including tumor resection (in 3 patients) and lateral temporal bone resection (in 15 patients). Superficial parotidectomy, resection of the mandibular condyle and neck dissection were concomitantly performed in 2, 1 and 2 patients, respectively.

The overall 5-year crude and disease-specific survival rates determined by the Kaplan-Meier method were 65.0% and 75.1%, respectively. The crude and disease-specific survival rates were significantly higher in patients with T1–3 tumors than in those with T4 tumors (P=0.002, P<0.001), and also significantly higher in patients who underwent surgery than in those who did not (P=0.001, P=0.007). Four patients died of the disease, including 3 with T4 disease and one 92-year-old super-elderly.

These results indicate the validity of surgical treatment for T1–3 cases and suggest that the therapeutic strategy needs to be reconsidered for T4 cases to improve the treatment outcomes.

Revision of the human immunodeficiency virus (HIV) treatment guidelines has led to long-term survival of HIV-infected patients. Although early treatment intervention can control the viral load, the incidence of non-acquired immune deficiency syndrome-defining cancer (NADC) has increased with the longer survival of the patients.

We report the case of a 52-year-old man with oropharyngeal cancer T1N2bM0 stage IVA (UICC 8 version) and HIV infection. Renal function became impaired after chemotherapy initiation, possibly caused by the adverse effects of the HIV antiretroviral drugs. In collaboration with HIV infection specialists, we altered the HIV antiretroviral drugs used, preventing deterioration of renal function. Additionally, induction chemotherapy and bioradiotherapy (BRT) were administered without adverse effects caused by lowered immunity. BRT is an effective option when immunological decline is concern.

Allergic diseases can strike at a low age. Diagnosis of childhood allergic rhinitis is difficult and often difficult to treat. We compared the symptoms of Japanese cedar/cypress pollinosis between untreated children (≤12 years) and adults (20–60 years) in the pollen release period who were clinically diagnosed as having cedar pollinosis. We evaluated nasal and ocular symptoms with the Japanese Allergic Conjunctival disease Quality of Life Questionnaire (JACQLQ), together with self-rated throat and breathing symptoms. In nasal symptoms, nasal congestion is more severe in children, and among ocular symptoms, the eyes are itchier in adults than in children. Symptoms of sore throat were more common in adults than in children, and acne eruptions were more common in adults. Our findings suggest that there is a difference between children and adults in the appearance of symptoms in cedar and cypress pollinosis.

The parapharyngeal space is an anatomically complex region containing the internal carotid artery, internal jugular vein and lower cranial nerves, and is one of the most difficult areas in the head and neck to obtain surgical access to. Herein, we report the case of a large malignant tumor in the parapharyngeal space excised by a microwave energy device-assisted endoscopic procedure.

A 60-year-old man presented with a 5-month history of a gradually enlarging mass in his upper right neck. Physical examination revealed a protuberance of the right posterolateral pharyngeal wall and palpable cervical lymph nodes bilaterally. Computed tomography and magnetic resonance imaging revealed a weakly enhancing mass with granular calcification measuring 50 mm in diameter in the right parapharyngeal space and enlarged bilateral upper cervical lymph nodes. Positron emission tomography revealed intense accumulation in these lesions. The findings of fine-needle aspiration cytology of the lymph node were categorized as class V, indicative of adenocarcinoma. Based on the findings, the patient was diagnosed as having a malignant tumor arising from the deep lobe of the parotid gland, and treated by a microwave energy device-assisted endoscopic resection of the tumor via a transcervical approach, combined with bilateral conservative neck dissection. The tumor was successfully and completely excised under clear visualization of the vessels and nerves, with minimal bleeding. The histopathological diagnosis was salivary duct carcinoma ex pleomorphic adenoma. The postoperative clinical course was uneventful, with no neurological deficit. The patient received postoperative radiotherapy (60 Gy/30 fractions) and has remained free from recurrence of the disease until now, 11 months after the surgery.

We stress that the blind space behind the tumor could be clearly visualized with the endoscope and that the vessels were cut and sealed efficiently and easily with the use of the microwave energy device, without damages to adjacent tissues. We conclude that the present procedure is useful for accurate and safe incision of parapharyngeal lesions.