Pleomorphic adenomas are the most common benign salivary gland tumors. However, there are rare cases of metastatic pleomorphic adenoma with a malignant-like course due to distant metastasis, despite there being no pathological evidence of malignancy. In this report, we describe two cases of metastatic pleomorphic adenoma.

Case 1 was a 24-year-old woman who underwent parotid tumor resection and was diagnosed with pleomorphic adenoma in year X. She developed local recurrence at X + 17, X + 19, and X + 21 years and underwent recurrent tumor resection, which revealed lumbar and lung metastases at X + 22 year. Metastatic tumor resection was also performed, but local recurrence and lumbar spine and lung metastases were observed. She died at X + 26 year due to respiratory failure caused by increased lung metastasis. Case 2 involved a 33-year-old woman who underwent excision of a palate tumor and was diagnosed with a pleomorphic adenoma in year Y. At Y + 5 year, local recurrence was observed, and resection of the recurrent tumor was performed; however, local recurrence and multiple bone and lung metastases were observed thereafter.

Although metastatic pleomorphic adenoma is considered to have a relatively good prognosis as a malignant tumor, even after metastasis occurs, careful follow-up and explanation to the patient are important because the final outcome may be fatal.

Peritonsillar abscess is common in adults but is relatively rare in children. Surgical treatment of peritonsillar abscesses in infants, such as incisional drainage, often requires general anesthesia for safety reasons. Therefore, it is necessary to accurately determine the indication for such treatment.

The patient was a 2-year-old boy who exibited fever, drooling, and decreased appetite, as well as enlarged right tonsil and left-sided deviation of the uvula. Contrast-enhanced CT scan showed a hypo-absorptive zone around the right tonsil, and the patient was admitted to the hospital on the same day with the diagnosis of right peritonsillar abscess. Although antibiotics were administered, the symptoms and findings did not improve. On the second day of hospitalization, incisional drainage of the right peritonsillar abscess was performed under general anesthesia. Postoperatively, the administration of antibiotics was continued, and the fever resolved quickly, drooling and loss of appetite improved, and the patient was discharged on the 11^th day of hospitalization.

Peritonsillar abscess in children is rare and its frequency is even lower in infants. As in the case of adults, surgical treatment, such as incision and drainage, are considered in addition to the administration of antimicrobial agents. However, general anesthesia is often required for surgical treatment in infants. It is important to determine the indication for surgical treatment as an indicator of the presence of airway stenosis, abscess diameter, and response to antibiotics.

This was a case of an 80-year-old woman, who presented to the clinic with the chief complaint of left jaw pain. CT showed erythema and swelling from the left temporal region to the left mandibular angle, and hypointense shadows mainly inside the temporalis muscle and masseter muscle along the perimandibular branch from the left temporal region to the mandibular angle. The margins were accompanied by contrast effect, and the patient was admitted to the hospital with a diagnosis of masticatory muscle space abscess. The patient also had a history of treatment with denosumab for bone metastasis from a previous left breast cancer, and bone exposure in the right lower central incisor and left upper lateral incisor, which was also associated with medication-related osteonecrosis of the jaw (MRONJ). The patient was treated with antimicrobial agents and incisional drainage and daily washing, and although improvement was observed, a small amount of pus continued to drain. Considering the patient’s wishes, the antimicrobial agents were changed to oral administration, and the patient was followed up on an outpatient basis.

In this case, the MRONJ was accompanied by a masticatory muscle abscess, and the treatment period required for the MRONJ-associated masticatory muscle abscess was longer than that for a masticatory muscle abscess without MRONJ. The duration of antimicrobial therapy was long and the course of treatment may be refractory. With the development of drug therapy for cancer treatment, long-term survival is now possible in many carcinomas. The number of patients with bone metastases treated with anti-RANKL monoclonal antibody products is expected to increase in the future. Thus, it is necessary to be aware of MRONJ and be cautious in the treatment of such patients.

Cervical subcutaneous emphysema is caused by trauma, surgical operation, or infection with gas-producing bacteria. The present case was a 52-year-old woman, who presented to our hospital with the chief complaint of neck pain and pharyngeal pain for 2 days. She was started on antibacterial medication after a simple CT scan of the cervicothoracic region showed adipose tissue opacity and emphysema in the subcutaneous region of the right neck. However, the next day, the symptoms worsened, and a contrast-enhanced CT scan of the cervicothoracic region showed enlarged mediastinal emphysema, which led to hospitalization. As tracheal wall thinning due to chronic irritation of the tracheal cannula was judged to have caused subcutaneous emphysema, the cannula was changed and intravenous broad-spectrum antimicrobial therapy was started. In this case, the tracheal cannula irritated the tracheal wall, and the thinning area became infected, causing perforation and subcutaneous emphysema. The rapid progression of the disease after admission suggested the possibility of necrotizing fasciitis. Prompt diagnosis of necrotizing fasciitis and early treatment with broad-spectrum antibacterial agents and debridement are important for an optimal prognosis.

Thyroid-like, low-grade nasopharyngeal papillary adenocarcinoma (TLLGNPPA) is a rare low-grade malignant tumor arising in the nasopharynx with papillary thyroid carcinoma-like histopathological findings and specific immunohistochemical features. Because of the limited number of cases reported to date, a standard treatment has not been established, and no unified method of tumor resection has been proposed.

A 31-year-old male patient was referred to our hospital for a nasal septal mass at the posterior end of the nasal septum, following a previous doctor’s visit for nasal discomfort lasting one month. Nasal endoscopy revealed a stalked mass with a base in the upper wall of the nasopharynx, and contrast-enhanced MRI showed a 7 mm-sized stalked mass with mild contrast effect. Tumor biopsy was performed and a diagnosis of TTF-1 positive and TG negative TLLGNPPA (cT1N0M0) was made. A nasal endoscopic resection was performed under general anesthesia with a safe margin in all directions, and the tumor was completely removed.

The Sonopet^®, a bone resection device, was used to resect the tumor, and it was possible to faithfully reproduce the expected resection line. On the other hand, the endoscopic view was obstructed due to splintering of bone fragments during cutting and the water supply, and thus, some modification of endoscopic manipulation was necessary.