Malignant external otitis following radiotherapy for oral cancer: A case report.

RATIONALE: Although an ototoxicity is well-known as adverse event of the radiotherapy, it is not widely known that immunosuppressed patients who underwent radiotherapy in head and neck region have risk of malignant external otitis. PATIENT CONCERNS: A 68-year-old man with diabetes, who had been diagnosed as intraosseous squamous cell carcinoma of the right mandible, underwent surgical resection. He received a total of 60 Gy/30Fr postoperative radiation. Four months after the course of radiation, he suffered from right aural fullness, otalgia and otorrhea. DIAGNOSES: Clinical examination revealed granulation and existence of Pseudomonas aeruginosa in the external auditory canal. Computed tomography showed expansive inflammation and erosion in the temporal bone. The patient is elderly and diabetes. These findings led to the diagnosis of malignant external otitis. INTERVENTIONS: The ear irrigation and administration of quinolones were started. Afterwards, fistula was formed in the oral cavity, and connected to the right external auditory canal. Therefore, irrigations were performed not only from ear but also from the oral fistula. OUTCOMES: Eight weeks after starting treatment, the malignant external otitis was completely healed. LESSONS: Physicians should raise awareness of malignant external otitis in immunosuppressed patients with oral cancer after radiotherapy.

[A Pediatric Case of Retropharyngeal Abscess Causing Multiple Instances of Cranial Nerve Palsy].

Deep neck abscesses are relatively rare in children compared with adults. Diagnosis can be difficult in pediatric patients because of the various clinical symptoms, therefore, it is important to correctly understand the pathology. We report herein on a rare pediatric case of a deep neck abscess that caused multiple instances of cranial nerve palsy. The patient was a 7-year-old boy who, despite treatment by a local physician for fever, swelling of the left neck and neck pain, developed torticollis, dysarthria, dysphagia and hoarseness and consequently consulted our department. We observed palsy associated with the IX, X, and XII left cranial nerves and a retropharyngeal abscess was diagnosed based on the computed tomography findings. The patient was hospitalized and underwent conservative treatment, and on day 21 of hospitalization, the patient was discharged after his symptoms had eased and the size of the abscess had reduced. We believe that palsy of the cranial nerves in the present case occurred as a result of pressure being applied to the cranial nerves in the carotid space due to an abscess in the retropharyngeal space.

Effect of a poly(ADP-ribose) polymerase-1 inhibitor against esophageal squamous cell carcinoma cell lines.

Effective molecular target drugs that improve therapeutic efficacy with fewer adverse effects for esophageal cancer are highly anticipated. Poly(ADP-ribose) polymerase (PARP) inhibitors have been proposed as low-toxicity agents to treat double strand break (DSB)-repair defective tumors. Several findings imply the potential relevance of DSB repair defects in the tumorigenesis of esophageal squamous cell carcinoma (ESCC). We evaluated the effect of a PARP Inhibitor (AZD2281) on the TE-series ESCC cell lines. Of these eight cell lines, the clonogenic survival of one (TE-6) was reduced by AZD2281 to the level of DSB repair-defective Capan-1 and HCC1937 cells. AZD2281-induced DNA damage was implied by increases in γ-H2AX and cell cycle arrest at G2/M phase. The impairment of DSB repair in TE-6 cells was suggested by a sustained increase in γ-H2AX levels and the tail moment calculated from a neutral comet assay after X-ray irradiation. Because the formation of nuclear DSB repair protein foci was impaired in TE-6 cells, whole-exome sequencing of these cells was performed to explore the gene mutations that might be responsible. A novel mutation in RNF8, an E3 ligase targeting γ-H2AX was identified. Consistent with this, polyubiquitination of γ-H2AX after irradiation was impaired in TE-6 cells. Thus, AZD2281 induced growth retardation of the DSB repair-impaired TE-6 cells. Interestingly, a strong correlation between basal expression levels of γ-H2AX and sensitivity to AZD2281was observed in the TE-series cells (R(2)  = 0.5345). Because the assessment of basal DSB status could serve as a biomarker for selecting PARP inhibitor-tractable tumors, further investigation is warranted.