Masaaki Higashino

A more appropriate clinical classification of benign parotid tumors: investigation of 425 cases

Abstract Conclusions: It is appropriate to clinically classify benign parotid tumors into three groups, i.e. superficial tumors, deep tumors, and lower pole tumors. Objective: It is important to classify benign parotid tumors based on location when deciding the surgical strategy and conducting clinical research. In this study, we examined a classification of benign parotid tumors that was useful for clinical practice. Methods: We studied 425 patients with benign parotid tumors who underwent surgery at our hospital. Their age, gender, tumor histopathology, maximum tumor diameter, postoperative facial nerve paresis, operating time, and blood loss were investigated after classifying the tumors as superficial tumors, deep tumors, or lower pole tumors. We also investigated the same parameters after dividing the lower pole tumors into superficial and deep types. Results: Lower pole tumors had distinct characteristics from superficial and deep tumors. The incidence of facial nerve paresis was significantly higher and the operating time was significantly longer for deep tumors than for either superficial or lower pole tumors, while there were no significant differences between superficial and lower pole tumors. In addition, there were no significant differences in any of the parameters between the superficial and deep types of lower pole tumor.

Novel differential diagnostic method for superficial/deep tumor of the parotid gland using ultrasonography

The purpose of this study was to prepare the ultrasonographic diagnostic criteria on parotid tumors for preoperative differentiation of superficial and deep tumors.

Interleukin-19 Downregulates Interleukin-4-Induced Eotaxin Production in Human Nasal Fibroblasts

BACKGROUND Interleukin-19 (IL-19), a member of the IL-10 family, is characterized as the cytokine suppressing the release and function of several proinflammatory cytokines. For regulation of local reaction in allergic rhinitis (AR), IL-19 might play an especially important role. METHODS We examined effects of IL-19 on IL-4-induced eotaxin production by human nasal fibroblasts. Early receptor-mediated events (expression of the suppressors of cytokine signaling (SOCS) and phosphorylation of signal transducer and activator of transcription 6 [STAT6]) by IL-19 was examined. Knockdown methods by RNAi were administered to investigate the involvement of those signal transductions. RESULTS Pretreatment with IL-19 downregulates IL-4-induced eotaxin production, but not interferon-γ(IFN-γ)-induced RANTES. Pretreatment with IL-19 suppressed the IL-4-induced STAT6 phosphorylation. The IL-19 induced SOCS-1, but not SOCS-3 or SOCS-5. The SOCS-1 knockdown by RNAi diminished pretreatment with IL-19-induced down-regulation of eotaxin production. CONCLUSIONS These results suggest that IL-19 down-regulates IL-4-induced eotaxin production via SOCS-1 in human nasal fibroblasts. In non-hematopoietic cells in AR, IL-19 might be an immunosuppressive factor.

Assessing the histological type and grade of primary parotid carcinoma by fine-needle aspiration and frozen section

OBJECTIVE The aim of this study is to compare preoperative fine needle aspiration cytology (FNAC) and intraoperative frozen section (FS) for the correct identification of malignancy, histological grade, and histological type. METHODS FNAC was performed on all 105 patients and FS on 71 patients with parotid carcinoma. RESULTS The rate of correctly determining the histological grade by FNAC and FS was 32% and 73%, respectively. The correct diagnosis rate for both the histological type and grade by FNAC and FS was 20% and 48%, respectively. CONCLUSIONS The correct grading of both high and low/intermediate grade carcinoma is possible in 70-80% of patients by FS. If the histological grade is identified correctly, the extent of resection can usually be decided appropriately. Therefore, we should put emphasis on determining the histological grade.

A clinicopathological study of parotid carcinoma: 18-year review of 171 patients at a single institution

BackgroundThis study investigated the clinical outcomes of patients with parotid carcinoma at a single institution during an 18-year period, with the focus on diagnosis, treatment, and survival.MethodsThe subjects were 171 patients with parotid carcinoma treated at our department during the 18-year period from September 1999 to August 2017. There were 19 patients in stage I, 65 patients in stage II, 22 patients in stage III, and 65 patients in stage IV. The symptoms, preoperative diagnosis, node metastasis, survival rate, prognostic factors, and immunohistological findings were investigated.ResultsPreoperative diagnosis of the histological grade by fine-needle aspiration cytology was only possible in 34% of the patients, while the histological grade was correctly determined by frozen section biopsy in 72%. The overall frequency of lymph node metastasis was 29%, with 59% in patients with high-grade carcinoma and only 6% in those with low-/intermediate-grade tumors. The disease-specific 5-year survival rate was 100% for patients in stage I, 95.2% in stage II, 70.4% in stage III, and 45.1% in stage IV. Multivariate analysis showed that the pathological grade was the most important prognostic factor. Immunohistological investigation showed patients with HER-2 or androgen receptor-positive tumors had a significantly worse prognosis.ConclusionsAlthough a high-grade tumor is the most important prognostic factor, preoperative diagnosis of the grade was not always accurate. Since advanced cancer has a poor prognosis with a limited response to surgery and radiation therapy, development of new treatment strategies, such as molecular-targeting therapies directed against HER-2 and AR, is required.

Radiotherapy concurrent with S-1 and radiotherapy alone for T2N0 glottic carcinoma: a retrospective comparative study.

OBJECTIVE We examined the completion rate, safety, and adverse events in patients with T2N0 glottic carcinoma who received chemoradiotherapy with S-1 (tegafur-gimeracil-oteracil potassium). METHODS In T2N0 glottic carcinoma patients, we retrospectively compared the local control rate and outpatient therapy completion rate between 20 patients who received radiotherapy plus S-1 (S-1 group) and 20 who received radiotherapy alone (RT group). RESULTS Local recurrence was not detected in any of the 20 subjects from the S-1 group, whereas local recurrence was found in 4 of the 20 subjects (20%) from the RT group (p<0.05). Outpatient treatment was completed by 15 of the 20 subjects from the S-1 group and 17 of the 20 subjects from the RT group (p=0.43). CONCLUSION We investigated chemoradiotherapy with S-1 in patients who had T2N0 glottic carcinoma and found a higher local control rate when compared with radiotherapy alone as well as comparable safety for outpatient delivery.

Operative technique for benign submandibular gland mass without identifying the mandibular branch of the facial nerve

OBJECTIVE The marginal mandibular branch of the facial nerve must be protected during surgery for benign diseases of submandibular gland. Methods for protecting the marginal mandibular branch include the nerve identification method and the non-identification method. METHODS We performed submandibular gland surgery in 138 patients with benign submandibular gland diseases using the non-identification method to preserve the marginal mandibular branch. In brief, the submandibular gland capsule is incised at the inferior border of the gland and detached along the gland parenchyma. The nerve is protected by this procedure without the need for identification. RESULTS Among 138 patients who underwent this surgical procedure, only 7 patients developed transient paralysis of the lower lip. CONCLUSION This method of resecting the submandibular gland without identifying the marginal mandibular branch is an effective procedure associated with a low incidence of transient paralysis. Moreover, no patient developed paralysis due to procedural errors.

A Case of External Dental Fistula-The Protection of the Mandibular Branch of the Facial Nerve-

We experienced a case of external dental fistula that opened from a mandibular lesion. The patient was a 21-years-old woman. She noticed the tumor in a mandibular lesion she had had on her right side since childhood, and left it. It continued to increase in size and became more painful so she sought treatment. She was given treatment of antibiotics, but this was ineffective, so an operation of partial excision was done. However, pus continued to flow from the fistula of the mandibular lesion. So she was referred to our department. The pus disappeared by antibiotic treatment but the fistula remained. We decided to operate. Generally, to protect the facial nerve and avoid paralysis of it while operating on a tumor of the mandibular lesion, method not it confirming the nerve is more safe than the method to confirm it. But, with this case, we had to confirm the nerve to protect it, because the fistula existed near the running of the nerve. It is better to confirm the facial nerve at the top of the inner side of the lower jaw corner, because there is a part before the shared branch. The running and the branch of the nerve vary, so it is difficult to confirm the facial nerve before the operation. So, we need to thoroughly explain to the patient about the possibility of facial nerve damage before the operation of mandibular lesion, especially if inflammation is involved, as in this case.