Schwannoma is an ectodermal benign tumor which arises from Schwann cells of the nerve sheath. It sometimes occurs in the maxillofacial region, but intraosseous schwannoma of the maxilla is extremely rare. We report a case involving a 15-year-old female patient who developed intraosseous schwannoma of the maxilla without a capsule. She was referred to our department due to pain in the left upper jaw. A mucosal ulcer with swelling was observed in the left hard palate, and computed tomography revealed a tumor with a clear margin in the maxilla. The lesion was surgically removed under general anesthesia and pathologically diagnosed as schwannoma, Antoni type A without a capsule. The tumor was thought to have arisen intraosseously according to imaging and surgical findings. Observing schwannoma in the maxilla, with no capsule, is extremely rare. No recurrence was observed three years after surgery.

OBJECTIVES:This study sought to identify tumor characteristics that associate with regional lymph node metastases in squamous cell carcinomas originating in the upper gingiva.MATERIALS AND METHODS:Data from 113 patients from Osaka University Dental Hospital were included. We measured each primary tumor's width, length, depth, and the extent of bone invasion. Additionally, tumor signal intensity for T1 and T2-weighted images as well as the center of the tumor's location and T classification was assessed, and a histopathological analysis was performed.RESULTS:Tumor signal intensity was not found to be a significant prognostic factor. However, bucco-lingual width, histopathological classification as well as the tumor's location were significantly different between metastatic and non-metastatic groups in both univariate and multivariate analysis. Superior-inferior depth and T classification were significant only in the univariate (and not the multivariate) analysis.CONCLUSIONS:Bucco-lingual width, histopathological grading as well as the tumor's location are likely to be important predictors for the occurrence of LN metastasis in upper gingival carcinoma patients and should be considered when managing care for these patients.

INTRODUCTION:This study aimed to construct a predictive scoring system for inferior alveolar nerve injury (IANI) following lower third molar (LM3) surgery based on cone-beam computed tomography (CBCT) images. MATERIAL AND METHODS:Of the 1573 patients who underwent LM3 removal following the CBCT, 39 with IANI and 457 randomly selected patients without IANI were enrolled. We collected information regarding the demographic characteristics of the patients, surgical situations, and inferior alveolar canal (IAC)-related CBCT factors. The association with IANI-risk was evaluated with a backward stepwise logistic regression model as per the Akaike information criterion. Scoring models' abilities of discrimination (area under the curve) and calibration (Hosmer-Lemeshow test and calibration plots) were assessed, followed by evaluation of the clinical usefulness using decision curve analysis. RESULTS:As per the multivariate analysis, the coronal positioned IAC on the enlarged root (odds ratio [OR], 3.78; P = 0.001), the length of perforated IAC (>3.4 mm) (OR, 3.05; P = 0.012), lingual/inter-radicular position of the IAC (OR, 3.96; P = 0.001), multiple roots closed to the perforated IAC (OR, 2.78; P = 0.025), and age >30 y (OR, 2.31; P = 0.076) were identified in the extended scoring model ranging from 0 to 12. This model was compared with our previously constructed baseline model that involved the latter three variables mentioned above, resulting in superior performance than that of the baseline model. CONCLUSION:The extended model would be a useful tool for reliable determination of the preoperative probability of IANI.

6582 Background: We previously developed a super-selective intra-arterial chemotherapy (iaCT) approach for head and neck cancer (HNC), by which, an intra-arterial catheter is retrogradely inserted via either the superficial temporal artery (STA) or occipital artery (OA) and connected to a subcutaneous reservoir. As a result, since this approach overcomes the need for frequent fluoroscopy sessions, the infusion frequency can be increased and the therapeutic effectiveness improved. However, since the anticancer effect is limited to the region supplied by the selected blood vessel, it is often difficult to control an advanced HNC by single-catheter iaCT. Subsequently, a novel multiple-catheter implantation method (MCIM) for super-selective iaCT has been developed using, both, the STA and OA. Methods: A total of 21 patients with stage III or IV HNC were enrolled in this study and treated via MCIM for iaCT between 2009 and 2017. The catheters were super-selectively placed in the tumor-feeding arteries after having entered the STA or OA. The first catheter was introduced into one of the target branches. Next, a second catheter was introduced into another target branch. If a third catheter was required, the procedure was repeated. The extra-arterial portions of the catheters were subcutaneously connected to an implanted juxta-mastoidal infusion reservoir. Results: The response rate was 100%; particularly, 20 cases of complete response and 1 of partial response were confirmed. Although the partial responder underwent salvage surgery and two complete responders ultimately died (due to either delayed recurrence or brain metastases), the other 18 patients have been living cancer-free for 2-9 years. Conclusions: The MCIM method allows to expand the infusion region while maintaining the main advantages of super-selective iaCT. As a consequence, due to the lack of need for patient confinement in the catheter room and for frequent fluoroscopy sessions, patients’ mental and physical distress, medical expenses, and treatment time are all ultimately reduced.

This study aimed to longitudinally assess the risk of facial nerve injury (FNI) in the surgical repair of mandibular condylar neck and subcondylar fractures (CN/SCFs) and to explore its predictors.

BACKGROUND:In our department, patients with oral squamous cell carcinoma(OSCC)received preoperative chemotherapy containing S-1 to prevent the growth and dissemination of tumors during the waiting time before definitive surgery. We retrospectively evaluated the usefulness of this treatment.PATIENTS AND METHODS:One hundred and five patients comprising stages T1(26), T2(64), T3(7), and T4(8 cases)were enrolled in this study from July 2001 to June 2013. In principle, patients were administered S-1(80mg/m / 2/day, days 1-14)and followed by a drug holiday(days 15-21), continuing until 1 week before surgery.RESULTS:The median administration period was 14 days(256 days). Ninety-eight patients underwent definitive surgery, but 7 patients who revealed clinical CR underwent only biopsy and showed histological CR. The histological responses of all patients were CR(24), PR(22), and NC(59), and the response rate was 43.8%. Almost all adverse effects were Grade 1 or 2, except 1 case of neutropenia(Grade 3)and 1 case of urticaria(Grade 3). The 5-year overall survival rates were 86.7% in all cases, 95.3% in CR/PR cases, and 79.7% in NC cases.CONCLUSION:Preoperative S-1 administration during the waiting time was a safe and very effective method and was considered beneficial for patients with OSCC.

6038 Background: We developed a superselective intra-arterial chemotherapy (iaCT) approach for oral cancer wherein an intra-arterial catheter is retrogradely inserted via the superficial temporal artery (STA) and/or occipital artery (OA). In most iaCT cases, high-dose anticancer agents are administrated via the intra-arterial catheter weekly or biweekly with daily irradiation. This approach remarkably improves curative efficiency, but some adverse events, e.g., severe mucositis, dysphagia, dysgeusia, dry mouth, and radiation osteonecrosis, mainly because of irradiation, decrease the quality of life. Methods: Thirty-two patients with stage II, III, or IV oral squamous cell carcinoma were treated using this new iaCT approach. The catheter was superselectively placed in the tumor-feeding arteries by cut-down of STA or OA. The catheter was completely placed under the skin and was connected to an infusion reservoir that was subcutaneously implanted around the mastoid process via the subcutaneous tunnel, ensuring little possibility of catheter-related issues such as infection and displacement of catheter. Anticancer agents (30 mg/m2of cisplatin with/without 10 mg/m2of docetaxel) were intra-arterially administered via the reservoir twice a week for 3 weeks, 180 mg/m2/6 times in total, without irradiation. The treatment effect was assessed using computed tomography, positron emission tomography, and biopsy. Results: The response rate of this approach was 100%, with 31 and 1 case having complete response (CR) and partial response (PR), respectively. Five patients with delayed regional lymph node metastasis or PR underwent salvage surgery; 28 patients (87.5%) had disease-free survival, while 2 (6.2%) died due to local recurrence and 2 due to distant metastasis. All patients developed CTCAE v4.0 Grade 2 oral mucositis in the flow area of the intended artery, most of which disappeared in half a year. No dry mouth, dysgeusia, and eating disorder were observed because the patients did not receive radiotherapy. No systemic adverse events such as hematologic toxicity and renal and/or hepatic injuries occurred. Conclusions: This method improved the adverse event of iaCT with radiotherapy, and the main advantage of superselective iaCT was not lost.

Lipoma involving multiple fascia! spaces is extremely rare and poses a challenge to surgeons using less invasive procedures. Although blunt dissection using a finger is often used in excisional surgeries as a supplementary maneuver, few cases have been described using the bimanual technique for the removal of these extensive lesions. Herein, the authors present a large lipoma of the oral floor extending to the unilateral submandibular and parapharyngeal spaces, which was excised only via a submandibular approach using the "push-pull down" maneuver, blunt finger dissection of the tumor with counter-pushing on the overlying mucosa to the submandibular direction facilitated tumor separation. The tumor was consequently pulled down and removed without an additional intraoral incision. Based on accurate preoperative examinations, this maneuver, provides a less invasive surgery for well-encapsulated benign tumors involving multiple fascia] spaces.

In the application of percutaneous approaches for mandibular condyle fractures, facial nerve injury (FNI) has been the most troubling aspect associated with surgical repair. 1 Ellis E. McFadden D. Simon P. et al. Surgical complications with open treatment of mandibular condylar process fractures. J Oral Maxillofac Surg. 2000; 58: 950 Abstract Full Text Full Text PDF PubMed Scopus (183) Google Scholar The conventional classification of these approaches according to the incision site does not reflect the risk of FNI owing to diverse dissection routes via a similar incision, 2 Al-Moraissi E.A. Louvrier A. Colletti G. et al. Does the surgical approach for treating mandibular condylar fractures affect the rate of seventh cranial nerve injuries? A systematic review and meta-analysis based on a new classification for surgical approaches. J Craniomaxillofac Surg. 2018; 46: 398 Crossref PubMed Scopus (42) Google Scholar which have confused surgeons and residents who intend to minimize the morbidity. 3 Imai T. Nakazawa M. Uzawa N. Four-step chart of percutaneous approaches to the mandibular condyle: A proposal of a visualized system for intuitive comprehension. J Oral Maxillofac Surg. 2019; 77: 238 Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar Equivocal examples in the treatment of condylar neck and subcondylar fractures include approaches via retromandibular incisions (transparotid, retroparotid, and transmasseteric anteroparotid [TMAP] approaches), as well as those via submandibular incisions (traditional submandibular [Risdon] and high perimandibular [high cervical TMAP] approaches). 3 Imai T. Nakazawa M. Uzawa N. Four-step chart of percutaneous approaches to the mandibular condyle: A proposal of a visualized system for intuitive comprehension. J Oral Maxillofac Surg. 2019; 77: 238 Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar From the viewpoint of the risk of FNI, the classification of percutaneous approaches based on dissection routes as well as the incision site would be more reasonable than a classification based on the incision site alone. 2 Al-Moraissi E.A. Louvrier A. Colletti G. et al. Does the surgical approach for treating mandibular condylar fractures affect the rate of seventh cranial nerve injuries? A systematic review and meta-analysis based on a new classification for surgical approaches. J Craniomaxillofac Surg. 2018; 46: 398 Crossref PubMed Scopus (42) Google Scholar

The study aimed to stratify the risk of inferior alveolar nerve injury (IANI) after lower third molar (LM3) surgery with a scoring system using identified predictive factors based on cone-beam computed tomography (CBCT) images. In a case–control study, the primary outcome was IANI occurrence. The control group included randomly selected patients without IANI. Predictor variables included patient demographics, surgical situations, Pell–Gregory classification, and inferior alveolar canal (IAC)-associated factors on CBCT. Study variables were analyzed using logistic regression models. Risk stratification was assessed by a scoring system that was constructed using independent predictors. The 858 patients who underwent LM3 surgery (1177 teeth) after CBCT scan were divided into case (25 patients, 2.9%, 27 teeth) and control (235 patients, 300 teeth) groups. In the multivariate model, lingual/inter-radicular position of IAC [odds ratio (OR) 7.21; P < 0.001; assigned score, 2], multiple roots closed to the IAC with cortical perforation (OR 3.72; P = 0.015; 1), and age > 30 years (OR 4.99; P = 0.008; 2) were associated with an increased IANI-risk. The IANI-risk scoring system could be stratified into low- and high-risk groups at a cutoff score of 3 (sensitivity, 68.0%; specificity, 90.6%; positive predictive value, 17.8%; positive likelihood ratio, 7.23). In conclusion, the high-risk group of IANI after LM3 surgery corresponded to individuals with multiple factors: lingual/inter-radicular IAC position to LM3, multiple roots with perforated IAC, and increased age (> 30 years). Raising awareness of the higher probability for IANI is needed for patients with multiple aforementioned factors.

Gingival enlargement, although frequently encountered in clinical settings, is rarely associated with systemic diseases or syndromes. Among the diverse pathological conditions of neurofibromatosis type 1 (NF-1), minor manifestations in the orofacial region are occasionally overlooked. Herein, the authors present an unusual case of gingival neurofibroma in a patient with NF-1 associated with characteristic osseous defects in the alveolus in the long-term course of 17 years from the first examination.A 5-year-old boy with NF-1 was referred for the evaluation of gingival enlargement in the posterior left maxilla. An incisal biopsy led to the diagnosis of neurofibroma. At 22 years of age, the patient was referred again with a complaint of bleeding and pain in the same region refractory to periodontal therapy. The gingiva and tuberosity were swollen, and the second molar was affected by the tumor. Radiography revealed a low level of the interdental septum beneath the tumor with a relatively intact periodontal cortical bone, exhibiting a teardrop-shaped bone defect. The lesion was completely resected with the periosteum.Gingival neurofibroma in NF-1 may be associated with osseous and dental abnormalities and can be mistaken for periodontitis. Raising awareness of this clinical entity can lead to proper management of the esthetic and functional problems in the oral and maxillofacial region.

壊疽性膿皮症（PG）は原因不明のまれな，急速進行性の潰瘍性皮膚疾患である。PGの初期症状は，術後創部感染と似ているため，診断が困難である。今回われわれは，口腔癌術後に生じたPG症例を経験したので報告する。患者は72歳女性で，下顎歯肉癌に対して胸三角筋部皮弁（D-P皮弁）による再建を伴う根治手術を行った。術後6日目に発熱，下痢とD-P皮弁挿入部周囲の顎下部皮膚の発赤，び慢性腫脹，接触痛ならびに皮弁挿入部からの排膿を認めた。この時点で，術後創部感染と診断した。抗菌薬の変更，デブリードメントとドレナージにもかかわらず，術後13日目には病変は患側頸部全般に拡がり，周囲に紅斑と青紫色の穿掘性境界を伴う有痛性の壊死性潰瘍が認められた。皮膚科に対診し，PGが強く疑われた。術後15日目よりプレドニゾロンとミノサイクリンの投与を開始し，数日で顕著な改善が得られた。皮膚生検では，好中球を主体とする著明な炎症性細胞浸潤が認められたが，細菌の存在は明らかではなかった。以上の臨床的および組織学的所見はPGの診断基準を満たすものであった。口腔顎顔面外科の手術においても，PGは術後合併症として念頭におくべき疾患である。

Percutaneous approaches to the mandibular condyle occupy a critical place in its open treatment. The selection of preauricular, submandibular, or retromandibular approaches depends mainly on the superoinferior level of the fracture site. Visualizing the path of dissection is straightforward using these traditional approaches. However, a number of percutaneous approaches, especially for condylar fractures, have been reported since the turn of the century. 1 Al-Moraissi E.A. Louvrier A. Colletti G. et al. Does the surgical approach for treating mandibular condylar fractures affect the rate of seventh cranial nerve injuries? A systematic review and meta-analysis based on a new classification for surgical approaches. J Craniomaxillofac Surg. 2018; 46: 398 Crossref PubMed Scopus (56) Google Scholar The developers of such approaches expounded their views on maximizing surgical site exposure and minimizing morbidities, 2 Ellis E. McFadden D. Simon P. et al. Surgical complications with open treatment of mandibular condylar process fractures. J Oral Maxillofac Surg. 2000; 58: 950 Abstract Full Text Full Text PDF PubMed Scopus (199) Google Scholar such as facial nerve injuries or visible scarring. In consequence, similar approaches have been presented using different nomenclatures and different approaches have used analogous terms, 3 Knepil G.J. Kanatas A.N. Loukota R.J. Classification of surgical approaches to the mandibular condyle. Br J Oral Maxillofac Surg. 2011; 49: 664 Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar which have confused oral and maxillofacial surgeons and trainees attempting to comprehend the concepts of these approaches. We propose a “4-step chart” as a road map for depicting the entire picture of percutaneous approaches to condyle management.

e18086 Background: In most intra-arterial chemotherapy (iaCT) cases, high-dose anticancer agents are administered weekly or biweekly via an intra-arterial catheter. This approach remarkably improves curative efficacy, but can cause adverse events that decrease the patients' quality of life or result in discontinuation of chemotherapy. Here, we describe a superselective iaCT approach for oral cancer, wherein the intra-arterial catheter is retrogradely inserted via the superficial temporal artery (STA) and/or occipital artery (OA). Methods: We applied this new iaCT method in 25 patients with stage II or III oral cancer. In this approach, the catheter was superselectively placed in the tumor-feeding arteries via STA/OA cut-down. The extra-arterial portion of the catheter was connected to an infusion reservoir implanted subcutaneously around the mastoid process through the subcutaneous tunnel. The catheter and reservoir were placed completely under the skin to reduce the possibility of catheter-related issues such as infection and displacement of the catheter from its intended position. Anticancer agents (30 mg/m2 of cisplatin with/without 10 mg/m2 of docetaxel) were intra-arterially administered through the reservoir twice a week for 3 weeks for a total doses of 180 mg/m2 of cisplaninwith 30 mg/m2 of docetaxel. Computed tomography, positron emission tomography, and biopsy were performed to evaluate the treatment effects. Results: All patients developed CTCAE4.0 Grade 2 oral mucositis in the flow area of the intended artery, with most cases resolving within 6 months. No systemic adverse effects such as hematologic toxicity or renal/hepatic injury were observed. Conclusions: The novel method described herein decreased the occurrence of iaCT-related adverse events while retaining the superselectivity advantage of iaCT.

e17569 Background: We have developed a superselective intra-arterial chemotherapy (iaCT) approach for oral cancer, in which intra-arterial catheter is retrogradely inserted via the superficial temporal artery and/or occipital artery. The extra-arterial portion of catheter is connected to an infusion reservoir implanted subcutaneously around the mastoid process through the subcutaneous tunnel. The catheter and reservoir are completely placed under the skin, so there is little possibility of catheter-related issues such as infection and displacement. Hence, out-patient iaCT (op-iaCT) can be performed. This method has improved ADL of patients without any loss of curative effect and oral function. We reported the usefulness of op-iaCT at the ASCO annual meeting in 2013. We assessed the long-term outcome and survival rate of patients with stage II and III oral cancer who received op-iaCT and survived for at least 5 years. Methods: We have used op-iaCT for 46 patients who had oral cancer, out of which we selected 14 patients with stage II and III oral cancer, and monitored them for more than 5 years. Results: Two patients died owing to distant metastasis, to the brain and liver, and 12 patients were cancer-free. Neck metastases were detected after primary treatment and op-iaCT in 3 patients, who were salvaged by neck dissection. The 5-year survival rate was 86%. Conclusions: Distant and/or regional lymph node metastases were observed in 5 out of 14 patients. The op-iaCT improves quality of life of patients with stage II and III oral cancer, but the metastasis rate is somewhat high. Close observation, intravenous chemotherapy, and /or prophylactic neck dissection should be employed in the op-iaCT approach for oral cancer.

We report a case of recurrent acute hemorrhagic rectal ulcer (AHRU) associated with prolonged bedridden condition due to worsening osteoradionecrosis of the jaw (ORNJ). An 83-year-old woman who had previously received chemoradiotherapy for oropharyngeal cancer was referred to our hospital to treat a perimandibular abscess due to ORNJ. The patient also had a medical history of brain infarction and bilateral femoral fractures. The abscess was controlled by pus drainage, debridement, and administration of antibiotics. On the 3rd hospital day, hematochezia abruptly occurred, colonoscopy revealed AHRU, and endoscopic hemostasis was performed. Then, rebleeding developed because of bedridden condition and worsening nutritional disorder. Nutritional support was continuously provided by a combination of intravenous and enteral nutrition, leading to improvement of undernutrition. The patient eventually underwent hemimandibulectomy without reconstruction. Elderly patients with atherosclerosis-related comorbidities are at risk for AHRU when bedridden because of their vulnerability to rectal ischemia. Bedridden patients with severe oral diseases such as progressive oral cancer and ORNJ also have a potential risk of AHRU.

e17567 Background: We developed a superselective intra-arterial chemotherapy (iaCT) approach to oral cancer, in which an intra-arterial catheter is retrogradely inserted through the superficial temporal artery and/or occipital artery with concurrent radiation therapy (RT). This approach remarkably improves the curative effect, but it decreases patients’ quality of life (QOL) because of prolonged hospitalization, severe stomatitis, lifelong dry mouth, dysgeusia, and radiation osteonecrosis of the maxillo-mandibular bone. Methods: This study assessed our new outpatient iaCT (op-iaCT) approach involving a subcutaneous infusion reservoir without concurrent RT. We included 23 patients, 11 with stage II and 12 with stage III oral cancer, and they were treated with the op-iaCT approach without concurrent RT. Using this approach, the chemotherapeutic agent was intra-arterially administered at the Outpatient Chemotherapy Center of Rinku General Medical Center. Results: The response rate to this approach was 100%, and all patients had a complete response. Four patients with secondary regional lymph node metastasis underwent neck dissection. Twenty patients were disease-free without an irradiation-related complication, whereas 3 patients died of distant metastasis (2) or local recurrence (1). With the exception of ambulatory visits twice per week for 3 weeks, patients’ activities of daily living (ADLs) were mostly unaffected. Moreover, patients rarely complained of dry mouth or dysgeusia, and they were free from radiation osteonecrosis after cancer therapy. Additionally, they did not develop oral dysfunction related to radical operation. Conclusions: In this approach, the catheter is implanted subcutaneously; therefore, common catheter-related issues rarely occur, resulting in good maintenance of ADLs. Moreover, patients can avoid the side effects of RT. Consequently, patient’s QOL improves and medical expenses decrease. Thus, our new op-iaCT approach improves QOL and the curative effect in patients with oral cancer if their ambulatory and performance status is good.

Since small cell carcinoma seldom arises in the maxilla, a standard treatment protocol has not been established. Thus, the treatment has been conducted by multimodal therapy including chemotherapy, referring to the guidelines for pulmonary small cell carcinoma. We report a case of maxillary small cell carcinoma in a 44-year-old man. Induction chemotherapy (CDDP+CPT-11), radiation therapy with concurrent intra-arterial chemotherapy (CDDP+TXT), surgical resection, and adjuvant chemotherapy (CDDP+CPT-11) were conducted. No recurrence or metastasis has occurred as of 20 months after treatment.

e17507 Background: Boron neutron capture therapy (BNCT) is a targeted type of radiotherapy that has a number of significant advantages over conventional external beam photon irradiation, especially in that radiation can be selectively delivered to tumor cells. We had, first in the world, treated with BNCT for a patient with recurrent head and neck cancer in 2001. In salivary gland carcinomas and sarcomas at head and neck region, unresectable cases or those with local recurrence after surgery, little efficient treatment modality has been developed. Methods: From December, 2001 to February, 2012, 11 intractable patients with non-squamous cell carcinoma (non-SCC) were treated with BNCT. Histopathologically, there were 7 patients with salivary gland carcinomas and 4 with sarcomas. All of them had received standard therapy and subsequently developed recurrent disease which have no other treatment options. All patients had received intravenously either a combination of two boron containing drugs, sodium borocaptate (BSH) 5g and borono phenylalanine (BPA) 250mg/kg or BPA 500mg/kg alone. Then they were treated with BNCT at the Kyoto University Research Reactor Institute. Results: All patients had advanced disease and 4 of 11(36%) had regional lymph nodes metastasis and distant metastasis, respectively. (1) 10B concentration ratios of tumor/normal tissue (T/N ratio), as determined by 18FBPA-PET imaging were mean 3.0 (2.2-4.0) for sarcomas and 2.8 (2.0-3.7) for salivary gland carcinomas. (2) Regression rates of sarcoma were CR: 2 patients (50%), PR: 2 (50%) patients and those of salivary gland tumor were CR: 4 (57%) and PR: 3 (43%). The overall response rate of both was 100%. (2) The mean survival time was 24.2 months and the 5year OS rates were 50% and 38%, respectively. (3) Survival times following BNCT ranged from 1 to127 months. (4) BNCT improved QOL, PS and survival period. (5) The primary adverse events were brain necrosis, osteomyelitis and transient mucositis and alopecia. Conclusions: Our results indicate that we could make sure that safety and effectiveness of BNCT and BNCT represents a new and promising treatment modality in non-SCC patients for whom there are no other treatment options.

In salivary gland pleomorphic adenoma, expression of extracellular matrix (ECM) substances indicates that tumor epithelial cells are becoming chondrogenic and will produce cartilage-like mesenchymal tissues. Sox9, the master transcription factor of chondrogenesis, is expressed in mouse salivary gland cells. To clarify the mechanism behind chondrogenesis in tumor epithelial cells, we examined the expression of transcription factors related to chondrogenesis in tumors and salivary glands. Reverse transcriptase-polymerase chain reaction (RT-PCR), quantitative real-time RT-PCR, and immunostaining were performed on pleomorphic adenoma tissues, salivary gland tissues, and human submandibular gland (HSG) cells. The mRNAs of essential transcription factors for chondrogenesis—Sox9, Sox6, and Sox5—were detected in both tumor and salivary gland tissues. The mRNAs of aggrecan and type II collagen—cartilage-specific ECM substances—were detected only in tumors. Sox9 and Sox6 proteins were colocalized in many epithelial cells in tumors and salivary glands. Tumor epithelial cells also possessed aggrecan protein and occasionally type II collagen protein. Moreover, mRNAs for transcription repressors of chondrogenesis δEF1 and AP-2 α were detected in both tumors and salivary glands, whereas Twist1 mRNA was detected only in salivary glands and was at significantly low-to-undetectable levels in tumors. Twist1 protein was localized in the Sox9-expressing salivary gland cells. HSG cells expressed Sox9, Sox6, and Twist1, but not aggrecan or type II collagen, and thus were similar to salivary gland cells. Twist1 depletion by Twist1 siRNA led to the upregulation of aggrecan and type II collagen mRNA expression in HSG cells. In contrast, forced expression of Twist1, using Twist1 cDNA, resulted in the downregulation of both these genes. Taken together, these results indicate that salivary gland cells have a potential for chondrogenesis, and Twist1 depletion concomitant with neoplastic transformation, which would permit tumor epithelial cells to produce cartilage-like mesenchymal tissues in salivary gland pleomorphic adenoma.