A 5-kV pulse generator with a 100-kV/µs slew rate based on series-connected 1700-V SiC MOSFETs for electrical insulation tests

This study demonstrates a high-slew-rate 5-kV pulse generator for electrical insulation tests. Electrical equipment, such as electrical actuators and traction drive motors, are exposed to severe electrical stress because recent switching inverters have high-frequency outputs with high supply voltages using wide-bandgap power devices. For an advanced electrical insulation test, a high-voltage pulse generator is required with a high slew rate; however, such generators suffer from large switching noise, followed by measurement noise, such as ground voltage fluctuations and radiation noise, hindering the detection of partial discharge (PD) phenomena. In this study, we propose a 5-kV pulse generator based on series-connected 1700-V silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). Four 1700-V SiC MOSFETs are connected in series as a 5-kV SiC switching module, constituting a half-bridge configuration for the pulse generator. The obtained switching waveforms exhibit fast rise times of 48 ns under 5 kV and 6.2 ns under 400 V with a low voltage overshoot and ringing owing to superior device characteristics and reduced parasitic inductances. Because of the low switching noise, we detect a clear PD signal with a 1500-V pulse when using the fabricated pulse generator for a PD test of a twisted pair. The proposed pulse generator uses a hard switching configuration such that the pulse generator can vary the pulse width from 150 ns to DC and increase the switching pulse cycle beyond 1 MHz by changing the control signals of the SiC MOSFETs.

A Case of Huge Cutaneous Verrucous Carcinoma of the Neck

Verrucous carcinoma (VC) is a rare subtype of squamous cell carcinoma. VC commonly occurs in the mucosa, but rarely occurs in the skin. The treatment for VC is surgical removal of the tumor. Because lymph node metastasis of VC is rare, the indications for prophylactic neck dissection for cutaneous VC of the neck are controversial. Here, we present the case of a 68-year-old man with a huge cutaneous VC of the neck and the long-term clinical course. The tumor occupied the entire right cervical skin, with suspected lymph node metastasis in the affected neck. Tumor resection and neck lymph node dissection were performed. Pathological examination revealed cutaneous VC with invasion to the adjacent tissues and no lymph node metastasis. Cutaneous VC of the neck is likely to grow locally without regional lymph node metastasis regardless of the long-term course and the size of the tumor.

Indications for and extent of elective neck dissection for lymph node metastasis from external auditory canal carcinoma

OBJECTIVES

We aim to clarify the frequency of lymph node metastasis of external auditory canal (EAC) carcinoma, including susceptible locations, adequate extent of elective neck dissection, and the relationship between the tumor infiltration site and lymph node metastasis.

PATIENTS AND METHODS

From 2003 to 2018, 63 patients with EAC carcinoma at Tokyo Medical and Dental University Hospital were enrolled in this study. The T and N stages, locations of clinically positive lymph nodes, prognoses, and anatomic site of tumor infiltration were analyzed after treatment.

RESULTS

Clinically positive lymph node metastasis (cN+) was detected in 18 patients (28.6%), consisting of T1, T2, T3, and T4 disease in 1 (6%), 2 (22%), 8 (38%), and 7 (41%) patients, respectively. The metastatic locations were at level II in 10 patients, parotid gland nodes in 7, preauricular nodes in 5, level Ib in 3, level Va in 3, level III in 1, and superficial cervical nodes in 1. Neck recurrence was determined in two of 45 patients with clinically negative lymph nodes (cN0), with the metastatic locations being levels II, Ib, and III. Among 18 cN+ cases, neck recurrence was noted in 2 of 9 patients who underwent neck dissection. Neck lesions were found to be manageable in all five patients who underwent docetaxel, cisplatin, 5-fluorouracil, and radiation therapy (TPF-RT). No relationship was noted between the tumor infiltration site and lymph node metastasis among T3/4 canrcinoma patients.

CONCLUSIONS

Elective neck dissection could be indicated only in T3/4 patients with free flap reconstruction. Levels Ib to III are considered appropriate for elective neck dissection in cN0 cases. Levels Ib to III and Va indicated favorable sites, even in cases with metastasis in the parotid gland or preauricular area. Furthermore, TPF-RT could be a useful option even in cN+ cases.

Endoscopy-Aided Combined Intraoral and Cervical Approach for a Huge Parapharyngeal Benign Tumor

We introduce here our surgical approach for the removal of a huge parapharyngeal tumor in 3 cases. Surgery was done under general anesthesia using transnasal intubation. Transoral manipulation was performed first. Using a tongue retractor and an angle widener, a wide surgical field was provided. Incision was made on the palate around the tumor. Tumor was separated from the surrounding tissue, preserving the tumor capsule. Then, a 5-cm small skin incision was made. Both parotid and submandibular glands were pushed upward, and the parapharyngeal space was opened. The tumor was also separated from the surrounding tissue. These manipulations were done under endoscopic observation. Finally, the tumor was pushed laterally and safely removed intraorally. After removal of the tumor, the wounds were closed, and vacuum drainage was settled for a few days. No apparent problems, such as malocclusion and facial palsy, occurred, and the patients were free from disease for more than 10 years. For the removal of a large parapharyngeal tumor, the mandibular swing approach is usually used; however, this approach is invasive, and certain sequelae, such as facial wound and malocclusion, may occur. Our technique enables the safe and less invasive removal of such a huge parapharyngeal benign lesion.

Otitis Media With Effusion Caused by a Parapharyngeal Tumor Showing Normal Nasopharyngeal Findings

The objective of this study is to evaluate otitis media with effusion (OME) among patients with parapharyngeal tumor. We have experienced 82 parapharyngeal tumor cases and encountered 14 patients complaining of hearing loss due to OME as the initial symptom. These patients showed normal nasopharyngeal findings and the presence of tumor had been detected long time after the beginning of their hearing symptoms (4 months to 13 years: median 2.5 years). Six patients had undergone ventilation tube insertion on the affected ear, which may lead to delay in diagnosis. Pathological examination was performed in 76 of 82 patients. Among these 76 patients, 13 showed OME. Seven patients had malignant lesions, whereas 6 had benign lesions. Therefore, malignant lesions are prone to occur with OME and its relative risk was 2.26 (95% confidence intervals, 1.16-4.42). This difference was statistically significant (P = .044, Fisher test). Otitis media with effusion is a very common disease and is well-known as a primary symptom of nasopharyngeal carcinoma. Therefore, nasopharyngeal observation is necessary for patients with intractable middle ear effusion. However, present 14 patients with OME showed normal nasopharyngeal findings and finally found after an imaging study. From our data, OME is an important but go-by symptom of parapharyngeal tumors. Imaging studies are potently useful for such patients with intractable OME.

Improving the Quality of Life of Patients With Severe Dysphagia by Surgically Closing the Larynx

OBJECTIVES:

The aim of this study was to elucidate the utility of the Kano method with surgical closure of the larynx by cricoid cartilage removal in improving quality of life in patients with severe dysphagia and their caregivers.

METHODS:

Nine patients with severe dysphagia who underwent the Kano method were evaluated for oral intake and activities of daily living using the functional oral intake scale and the Barthel index, respectively, as indices of quality of life. Additionally, nutritional status, inflammation, and postoperative complications were assessed. Furthermore, 7 family caregivers were queried regarding frequency of sputum suction, mood of family caregivers, and postoperative satisfaction.

RESULTS:

Functional oral intake scale and Barthel index scores as well as inflammation improved significantly after surgery ( P < .05). There were no severe complications or other complications requiring surgical intervention. The frequency of sputum suction was reduced postoperatively ( P < .05). The mood of family caregivers was significantly improved and satisfaction level was high postoperatively.

CONCLUSIONS:

Surgical closure of the larynx is an appropriate choice for patients with irreversible severe dysphagia and impaired articulation or vocal function because quality of life is improved for both patients and family caregivers and the satisfaction of family caregivers is sufficient.

An Unusual Invasive Ectopic Thymoma in the Thyroid and Anterior Mediastinum

An 81-year-old woman with a 2-year history of dysphagia detected a cervical mass. Computed tomography showed a thyroid tumor extending through the superior and anterior mediastinum. Analysis of an incisional biopsy specimen revealed a thymoma. Total resection of the thyroid and mediastinal tumor was performed. The thymoma invaded the anterior tracheal wall and left brachiocephalic vein. Pathologic examination revealed thymoma type B1 concomitant with B2 and B3 (World Health Organization classification), Masaoka IVb, and T3 N2 M0-IVb, with cervical lymph node metastasis. Clinicians must be cautious during radical operations for invasive ectopic thymomas.

A new method for selecting auricle positions in skull base reconstruction for temporal bone cancer

OBJECTIVE

In advanced temporal bone carcinoma cases, we attempted to preserve as much of the auricle as possible from a cosmetic and functional perspective. Difficulties are associated with selecting an adequate position for reconstructed auricles intraoperatively. We improved the surgical procedure to achieve a good postoperative auricle position.

METHODS

Nine patients were included in this study. All patients underwent subtotal removal of the temporal bone and resection of the external auditory canal while preserving most of the external ear, and lateral skull base reconstruction was performed with anterolateral thigh flaps. We invented a new device, the auricle localizer, to select the correct position for the replaced external ear. The head skin incision line and two points of three-point pin fixation were used as criteria, and a Kirschner wire was shaped as a basic line to match these criteria. Another Kirschner wire was shaped by wrapping it around the inferior edge of the external ear as the positioning line, and these two lines were then combined. To evaluate the postoperative auricle position, the auricle inclination angle was measured using head frontal cephalogram imaging.

RESULTS

The external ear on the affected side clearly drooped postoperatively in nonlocalizer cases, whereas this was not obvious in localizer cases. Auricle inclination angles 1 year after surgery significantly differed between these two cases (P = 0.018).

CONCLUSION

The surgical device, the auricle localizer, is useful for selecting intraoperative accurate auricle positions. The assessment index, the auricle inclination angle, is useful for quantitatively evaluating postoperative results.

LEVEL OF EVIDENCE

4 Laryngoscope, 2605-2610, 2018.

Patterns of stress coping and depression among patients with head and neck cancer: A Japanese cross-sectional study

OBJECTIVE

Patients with head and neck cancer (HNC) experience many stressful problems with breathing, eating, swallowing, and/or speaking. The aim of this study was to (a) identify the clusters of HNC patients based on their stress coping strategies and (b) evaluate the differences in clinical data and depression among the identified HNC patients' coping clusters.

METHODS

We conducted a single-center, cross-sectional study with self-completed questionnaires for patients with HNC between April and August 2013. We measured stress coping (an abbreviated version of the COPE Inventory: Brief COPE) and depression (the Japanese version of the Beck Depression Inventory-II: BDI-II).

RESULTS

Of the 116 patients who completed all the questionnaires, 81 (69.8%) participants were 60 to 79 years old and 105 (90.5%) were men. Cluster analysis based on the standardized z score of Brief COPE showed that patients were classified into 3 clusters, labeled "dependent coping," "problem-focused coping," and "resigned coping." The ANOVA revealed that depression (BDI score) was significantly higher in the dependent-coping cluster compared with the problem-focused coping.

CONCLUSIONS

This study indicates that patients with a dependent-coping pattern may account for the largest HNC population and are likely to suffer from depression. Dependent coping includes smoking, drinking, seeking support, or engaging self-distraction. In the future, we should develop psychological intervention programs focused on coping strategies and enhancement of the support system for patients with HNC.

Right dominance in the incidence of external auditory canal squamous cell carcinoma in the Japanese population: Does handedness affect carcinogenesis?

Objectives/Hypothesis

To investigate the relationship between handedness and the incidence of squamous cell carcinoma in the external auditory canal (EACSCC).

Materials and Methods

Sixty‐eight cases of EACSCC were enrolled in this study, and their affected side was checked. Handedness and ear‐picking habits were also investigated in 34 EACSCC cases. Handedness was judged based on self‐categorization, and the relationship between handedness and the affected side was investigated.

Results

Fifty‐two cases occurred on the right side, and 16 cases occurred on the left side of patients with EACSCC. The incidence of laterality in EACSCC showed a statistically significant right dominance. Concerning handedness, 29 cases were right‐handed, 4 cases were left‐handed, and 1 case was ambidextrous. Twenty‐seven out of the 29 right‐handed cases and 1 ambidextrous case suffered from carcinoma on the right side, whereas 3 left‐handed cases suffered from carcinoma on the left side. That is, most of the cases suffered from EACSCC on the same side as their handedness, and this tendency showed a statistically significant difference. Most of the patients with EACSCC experienced itching and habitual ear‐picking in the affected side.

Conclusion

Mechanical stimulations to the EAC, such as ear picking, may plausibly cause EACSCC. In Japan, ear picking, also called “mimikaki,” is a popular habit and an established unique culture. Because ear picking requires delicate handling and manipulation, this tends to occur on the same side as the handedness in the Japanese population. This is the first report about the relationship between handedness and carcinogenesis.

Level of Evidence

N/A.

[Combined Anterior Craniofacial Resection for Locally Advanced Ethmoid Carcinomas]

OBJECTIVE

Carcinoma of the ethmoid sinus is very rare, and treatment for locally advanced tumors remains as a formidable challenge to the clinician. We reviewed cases of ethmoid carcinoma in which anterior craniofacial resection had been undertaken and evaluated the safety and validity of the operative methods.

METHODS

We retrospectively reviewed 13 patients with ethmoid carcinoma who underwent combined anterior craniofacial resection. We evaluated the surgical procedures, complications, outcomes, local recurrence, and the survival rate.

RESULTS

Coronal incision and anterior craniotomy were performed in all cases. Four out of 13 cases underwent ipsilateral orbital exenteration due to involvement of the orbital contents. There were no potentially fatal complications, except for two cases of epidural abscesses which were successfully cured. Positive surgical margins were observed in 6 patients, and they received postoperative radiotherapy and/or chemotherapy. Local recurrences occurred in 4 cases, and 3 died at 9, 11, and 49 months after the surgery. Distant metastasis was not observed during the observation period. The overall 5-year survival rate was 75.2% (Kaplan-Meier method).

CONCLUSION

These tumors were safely removed without severe complications and postoperative mortality. Combined anterior craniofacial resection is an effective and safe option for treatment of locally advanced ethmoid carcinomas after various preoperative treatments.

Risk factors for cervical lymph node metastasis in superficial head and neck squamous cell carcinoma

INTRODUCTION

The necessity of transoral surgery for head and neck carcinoma is increasing, but its indications for the treatment of superficial head and neck carcinomas have not yet been established. This study was intended to help establish the standard indications for transoral surgery and additional therapy in patients with superficial head and neck carcinoma.

METHODS

Sixty-two patients with 83 superficial head and neck carcinoma underwent transoral tumor resection at the Cancer Institute Hospital between June 2006 and September 2011. We measured the tumor size and thickness, examined the gross appearance, permeation of vessels, and droplet infiltration, and analyzed the correlations between each parameter.

RESULTS

Sessile type of tumor on gross appearance showed a significantly higher incidence of thickness≥1000 µm than the other types. Tumor thickness≥1000 µm was associated with higher incidences of permeation of vessels, droplet infiltration, and cervical lymph node metastasis.

CONCLUSIONS

In superficial head and neck carcinoma, if the endoscopic gross appearance is the sessile type, tumor thickness is likely to be ≥1000 µm and risk of cervical lymph node metastasis is increased.

Extended orbital exenteration for sinonasal malignancy with orbital apex extension: surgical technique and clinical analysis

OBJECT

The majority of sinonasal malignancies present with advanced disease, and cure rates are generally poor. Surgical extirpation remains the mainstay of treatment. In cases of sinonasal malignancy with orbital apex extension, gross-total tumor resection requires orbital exenteration and bony skull base resection around the orbital apex to provide sufficient margins. In this retrospective study, the authors describe their surgical strategy in and technique for orbital exenteration with orbital apex resection in patients at Tokyo Medical and Dental University who had sinonasal malignancy with orbital apex extension. They also analyzed the clinical features of and the results in these patients.

METHODS

Between February 2001 and August 2012 at the authors' institution, sinonasal malignancy with orbital apex extension was treated using craniofacial tumor resection with orbital exenteration including skull base bone around the orbital apex. The authors describe this technique and analyze the surgical indications, extent of resection, primary tumor location, outcome, pathological findings, and neoadjuvant and adjuvant therapies of the patients who underwent the technique.

RESULTS

The patients consisted of 12 men and 3 women with a mean age of 47.7 years (range 14-79 years). The longest postoperative follow-up was 9.5 years, and the shortest was 0.67 year (mean 3.0 years). Tumor originated at the ethmoid sinus in 6 patients (40%), maxillary sinus in 5 (33%), nasal cavity in 2 (13%), and orbital cavity and maxillary bone in 1 patient each (7%). Histological analysis of tumor specimens revealed squamous cell carcinoma in 9 patients (60%), rhabdomyosarcoma in 2 (13%), and small cell carcinoma, mucoepidermoid carcinoma, adenoid cystic carcinoma, and Ewing sarcoma in 1 patient each (7%). Two patients experienced recurrences at 1 and 5 months after treatment; these patients died at 5 and 10 months after surgery, respectively. Estimated 5-year recurrence-free survival (RFS) was 86.7%, and estimated 5-year overall survival (OS) was 86.2%; there was no perioperative mortality. None of the patients had new neurological deficits as a result of the surgery, but 5 patients suffered infectious complications from the graft transplanted into the cavity after resection. There were no other perioperative complications.

CONCLUSIONS

These authors are the first to describe a technique for extended orbital exenteration with orbital apex skull base resection. The technique provided sufficient margins for gross-total resection of the sinonasal malignancy with orbital apex extension. The estimated 5-year OS and RFS rates were high, and the perioperative complication rate was acceptably low, demonstrating the safety and efficacy of this technique.

Clinical characteristics of Japanese oropharyngeal squamous cell carcinoma positive for human papillomavirus infection

CONCLUSION

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) is considered to be a distinct entity in Japan. The combination of both HPV-DNA sequencing analysis and immunohistochemistry (IHC) for p16(INK4A) is useful to discriminate the OPSCC patients with a better prognosis from other cases, especially in the advanced stage. Surgical treatment is recommended for HPV-negative advanced cancer.

OBJECTIVE

The number of HPV-related OPSCCs has been increasing worldwide. However, the incidence and prognostic significance of this cancer in Japan have not yet been fully elucidated.

METHODS

Seventy-seven Japanese patients with OPSCC were enrolled in this study. The prevalence of HPV-DNA was assessed by PCR and sequencing. The expression of p16(INK4A) and p53 was examined by IHC. The clinicopathological parameters and disease-specific survival were analyzed for HPV-positive and -negative patients.

RESULTS

HPV-DNA was detected in 32 patients. Thirty-four patients were p16(INK4A)-positive by IHC. The patients who were positive for HPV infection were significantly younger. Furthermore, in the stage III or IV cases, the 3-year disease-specific survival of the HPV infection-positive group was significantly better than that of the HPV-negative group. Surgical treatment was demonstrated to lead to a good prognosis for the patients with HPV-negative advanced cancer.

[What is the role of otolaryngologists in deglutition practice?--A survey for medical practitioners in different fields]

The advent of a super aging society is causing a rapid increase in the number of patients with dysphagia, and, in response, the use of percutaneous endoscopic gastrostomy (PEG) has become markedly widespread over the past decade. As the result of its rapid spread, PEG is controversial both ethically and economically, and, in the revision of medical treatment fees for 2014, the preoperative deglutition usability test of all cases is fixed for the full amount request requirements of gastrostomy. Thus, the demands on dysphagia practice are rising. Therefore, we conducted a survey of the dysphagia practice of otolaryngologists, doctors, and speech therapists in charge of dysphagia practice in hospitals, home medical care clinics, and dental offices in Itabashi-ku, Tokyo, and we considered the role of otolaryngologists in dysphagia practice. According to the survey, the roles that are expected of otolaryngologists in dysphagia practice are the evaluation of swallowing function using videoendoscopic examination of swallowing in over 50% of home medical care clinics and dental offices. On the other hand, surgical treatment is expected of otolaryngologists in over half in the hospital group. A total of 64% of the home care clinic group and 47% of the dental group did not coordinate with otolaryngologists in dysphagia practice because there are no otolaryngologists to consult. The home care clinic group indicated a demand of the swallowing function test in short-term admission or home practice. In the survey of departments of otolaryngology in hospitals or otolaryngology clinics, 40% of these institutions evaluate deglutition, while the other institutions did not perform evaluations because of the lack of human resources or deficient facilities. The otolaryngologist specializes in the laryngopharynx where aspiration occurs, and not only diagnoses local organic disease, but also directs the patient to a doctor in an appropriate department on the basis of understanding the patient's background diseases. We conclude that organized participation and leadership in this region are urgent tasks of otolaryngologist.

Nuclear resonant scattering measurements on (57)Fe by multichannel scaling with a 64-pixel silicon avalanche photodiode linear-array detector

We developed a silicon avalanche photodiode (Si-APD) linear-array detector for use in nuclear resonant scattering experiments using synchrotron X-rays. The Si-APD linear array consists of 64 pixels (pixel size: 100 × 200 μm(2)) with a pixel pitch of 150 μm and depletion depth of 10 μm. An ultrafast frontend circuit allows the X-ray detector to obtain a high output rate of >10(7) cps per pixel. High-performance integrated circuits achieve multichannel scaling over 1024 continuous time bins with a 1 ns resolution for each pixel without dead time. The multichannel scaling method enabled us to record a time spectrum of the 14.4 keV nuclear radiation at each pixel with a time resolution of 1.4 ns (FWHM). This method was successfully applied to nuclear forward scattering and nuclear small-angle scattering on (57)Fe.

Surgery for juvenile nasopharyngeal angiofibroma with lateral extension to the infratemporal fossa

OBJECTIVE

The study aimed to assess the usefulness of skull base surgery for large juvenile nasopharyngeal angiofibroma (JNA) with lateral extension to the infratemporal fossa.

MATERIALS AND METHODS

Eleven cases were enrolled for this study, and the mean age was 17.7 years old (range: 8-32). Six out of 11 cases underwent surgery as an initial treatment, and the other five underwent secondary surgery after initial surgery or radiotherapy in other institutions. The range of extension of tumor, feeding arteries, surgical approach, and treatment outcome were estimated.

RESULTS

All tumors originated from the sphenopalatine foramen. Based on the imaging study, there was extension to the cavernous sinus observed in eight cases, as well as to the middle cranial fossa (8), orbit (4), and anterior cranial fossa (1). These tumors were diagnosed as Andrews' Stage IVa (3) and IVb (8). However, infiltration into the cavernous sinus was observed in one case only during surgery. Ten tumors were separated carefully from the cavernous sinus or dura and were accurately diagnosed as Stage IIIb. In all cases, the main arterial feeders of the JNAs were branches of the external carotid artery, which were embolized prior to surgery. However, 10 cases were also fed by branches of the internal carotid artery (branches of the ophthalmic artery), in which these arteries could not be embolized. Coronal skin incision (1) and a facial dismasking flap (9) were used, and in one case, wide lateral skin incision with temporary incision of the facial nerve was applied. The orbito-zygomatic approach and its modification was applied to all the cases. Fronto-lateral craniotomy was applied in four cases and lateral craniotomy in seven cases. Total resection was achieved in 10 cases and subtotal resection in one case. No mortality was noted in this series. Temporal trismus was observed in all cases which subsided gradually. Cheek numbness and facial palsy were observed in three and two cases, respectively.

CONCLUSION

Coupled with craniotomy, tumor removal was successfully carried out in 11 patients with JNAs, which showed large lateral extension. Our surgical strategy is a safe and effective approach for the removal of JNAs with infratemporal fossa extension.

Japanese Board Certification System for head and neck surgeons

The Japan Society for Head and Neck Surgery (JSHNS) started a board certification system for head and neck surgeons in 2010. To become certified, the following qualification and experiences are required: (1) board certification as otorhinolaryngologist, (2) 2 years of clinical experience in a board-certified training facility, (3) clinical care of 100 patients with head and neck cancer under the supervision of board-certified faculty and (4) surgical experience in 50 major head and neck surgical procedures, including 20 neck dissections, under the supervision of board-certified faculty. The following scientific activities are also required during the preceding 5 years: (1) two clinical papers on head and neck cancers presented at major scientific meetings, (2) one clinical paper on head and neck cancer published in a major journal, (3) attendance at two annual meetings of JSHNS and (4) enrolment in three educational programs approved by JSHNS. The qualifying examination consists of multiple choice tests and oral examinations. A total of 151 head and neck surgeons were certified in 2010 followed by 43 in 2011 and 34 in 2012, while the membership of JSHNS dramatically increased from 1201 in 2007 to 1748 in 2013. Although the board certification system for head and neck surgeons was started only recently, it has encouraged many residents and fellows as well as established head and neck surgeons. We believe that this system will contribute to further advancement in the clinical practice for head and neck cancers in Japan.

Clinicopathological significance of androgen receptor, HER2, Ki-67 and EGFR expressions in salivary duct carcinoma

BACKGROUND

Salivary duct carcinoma (SDC) is a highly aggressive disease which often metastasizes to distant sites, and there is no established standard therapy for this systemic disease. Given that SDC is biologically similar to breast and prostate cancer, anti-androgenic receptor (AR) and anti-human epidermal growth factor receptor 2 (HER2) therapies have the potential to exert effects, not only on patients with breast and prostate cancer but also on those with SDC.

METHODS

The expression levels of HER2, epidermal growth factor receptor (EGFR), Ki-67, and AR were assessed in 32 patients with SDC, and their correlations with overall survival (OS) and disease-free survival (DFS) were analyzed retrospectively. SDC was classified into five subtypes using a method similar to that used for breast cancer.

RESULTS

Anti-AR, HER2, and EGFR were positive in 23 (71.9 %), 14 (43.8 %), and 26 (81.3 %) cases, respectively. One or more of these 3 factors were positive in 30 (93.8 %) cases. The Ki-67 labeling index was greater than 15 % in all cases. While molecular status did not correlate with OS, EGFR and AR positivity were significantly associated with DFS in univariate analysis. Multivariate analysis revealed that EGFR was the only independent predictor of DFS.

CONCLUSIONS

The statuses of some molecules are useful to predict DFS in patients with SDC. Ki-67 overexpression suggests that cytotoxic agents are effective for SDC. Since the majority of SDCs express AR, HER2, and/or EGFR, assessing and targeting these molecules are promising strategies to improve the prognosis of unresectable, metastatic or recurrent SDC, and a classification system according to the molecular expression status may be useful to select appropriate therapy.

Cervical lymph node metastasis from early-stage squamous cell carcinoma of the oral tongue

CONCLUSIONS

The findings of this study demonstrated that the wait-and-watch strategy for neck metastasis from squamous cell carcinoma (SCC) of oral tongue is a reliable option and that salvage by surgical treatment is effective. However, younger patients should be closely monitored for recurrence. Adjuvant therapy may be recommended for patients with pathologically advanced disease.

OBJECTIVES

Metastatic involvement of cervical lymph nodes is the most important prognostic indicator in patients with oral tongue SCC. With the objective of determining the most appropriate treatment strategy for regional recurrence, we conducted a retrospective review of clinicopathologic factors.

METHODS

The clinicopathologic features of 103 patients with oral tongue SCC, in whom the local lesions were treated successfully by low-dose interstitial brachytherapy (LD-IBT), but who subsequently developed cervical lymph node metastases and were treated by salvage surgery, were reviewed.

RESULTS

In the patients who underwent surgical treatment at our hospital, 5-year disease-free survival and regional control rates were 69.3% and 85.3%, respectively. The clinicopathologic factors significantly associated with unfavorable disease-free survival were the presence of extracapsular spread (hazard ratio (HR) = 3.005, p = 0.045), multiple and large lymph nodes (HR = 2.850, p = 0.010 and HR = 3.112, p = 0.007, respectively), younger age (HR = 2.429, p = 0.048), and shorter interval from the LD-IBT to detection of neck metastasis (HR = 1.749, p = 0.013).

A new concept for classifying skull base defects for reconstructive surgery

To classify the defects of the skull base, we present a new concept that is intuitive, simple to use, and consistent with subsequent reconstructive procedures. The centers of defects are determined in the anterior (I) or middle (II) skull base. The defects are classified as localized in the defect's center (Ia, IIa) or extended horizontally (Ib, IIb) or vertically (Ic, IIc) from the defect's center. Accompanying defects of the orbital contents and skin are indicated by "O" and "S," respectively. An algorithm for selecting subsequent reconstructive procedures was based on the classification. Using the new system, we retrospectively reclassified 90 skull base defects and examined how the defect classifications were related to the reconstructive flaps used and postoperative complications. All defects were reclassified with the new system without difficulty or omission. The mean correlation rate was high (88%) between the flaps indicated by the new classification and the flaps that had actually been used. The rate of postoperative complications tended to be higher with Ia, Ic, and IIb defects and combined defects. Our new classification concept can be used to classify defects and to help select flaps used for subsequent reconstructive procedures.

[Thiel's method of embalming and its usefulness in surgical assessments]

When we assess anatomical problems and the safety and effectiveness for performing a difficult surgical procedure or planning novel surgical approaches, preoperative human dissections are very helpful. However, embalming with the conventional formaldehyde method makes the soft tissue of the cadaver harder than that of a living body. Therefore, the cadaver embalmed with conventional formaldehyde is not appropriate for dissections when assess surgical approaches. Thiel's method is a novel embalming technique, first reported by W. Theil in 1992. This method can preserve color and softness of the cadaver without risk of infections. We have used cadavers embalmed with Thiel's method for preoperative assessments and have confirmed the usefulness of this method especially for the prevention of complications or in assessing surgical approaches. The cadaver embalmed with this method has several advantages over other embalming methods and it might be also useful for the developments of new surgical devices or evaluation of a surgeon's skill.

Increased plasma LIGHT levels in patients with atopic dermatitis

LIGHT [the name of which is derived from 'homologous to lymphotoxins, exhibits inducible expression, competes with herpes simplex virus glycoprotein D for herpes simplex virus entry mediator (HVEM), and expressed by T lymphocytes'], is a member of the tumour necrosis factor superfamily that is involved in various inflammatory diseases. We aimed to estimate the relevance of plasma LIGHT levels as a biomarker for atopic dermatitis (AD). In order to understand the putative role of LIGHT in AD pathogenesis, we also investigate the effects of LIGHT on a monocytic cell line, human acute monocytic leukaemia cell line (THP-1). We examined plasma LIGHT levels, total serum IgE, serum value of CCL17 and peripheral blood eosinophil counts in patients with AD and healthy subjects. The effects of LIGHT on activation and apoptosis in THP-1 cells were also investigated. The plasma concentrations of LIGHT in AD patients were significantly higher than those in healthy individuals and the concentrations decreased as the symptoms were improved by treatment. The LIGHT plasma concentrations correlated with IgE levels and the Severity Scoring of AD (SCORAD) index. In addition, LIGHT stimulation increased expression of CD86 and induced production of interleukin-1β in THP-1 cells. Apoptosis was inhibited, the Bcl-2 level increased and the caspase-3 level decreased in THP-1 cells stimulated with LIGHT, compared to unstimulated control cells. These results suggest that plasma LIGHT levels may be one of the promising biomarkers for AD.

Review of skull base reconstruction using locoregional flaps and free flaps in children and adolescents

Tumors of the skull base are rare in children, and reconstruction in such patients has rarely been reported. We reviewed 16 cases of skull base reconstruction in patients under 18 years. The study group consisted of 10 boys and 6 girls, whose ages ranged from 2 to 17 years. Of the 16 cases, eight tumors were benign and eight were malignant. Defects were anterior in six cases, lateral in eight cases, and anterolateral in two cases. Reconstruction was performed with locoregional flaps in 11 cases and with free flaps in 5 cases. No significant difference was found between locoregional flaps and free flaps in total operative time, intraoperative blood loss, or postoperative hospital stay. However, in some cases, total operative time, reconstruction time, and blood loss increased to a degree unacceptable for pediatrics. Minor complications occurred in three patients and a major complication occurred in one case. Of four patients, three patients with postoperative complications had undergone chemoradiotherapy. Because of the physical weakness of pediatric patients, complicated reconstructive procedure should be avoided. We believe locoregional flaps will become the first choice for reconstruction. However, if patients have large, complex defects and have received radiotherapy, appropriate free flaps should be used to avoid postoperative complications.

Prevalence of esophageal cancer during the pretreatment of hypopharyngeal cancer patients: routinely performed esophagogastroduodenoscopy and FDG-PET/CT findings

BACKGROUND

The prevalence of esophageal cancer accompanied by hypopharyngeal cancer (HPC) is high and increasing rapidly in Asia. The purpose of this prospective study was to evaluate the prevalence of esophageal cancer during the pretreatment of HPC patients who were routinely examined using esophagogastroduodenoscopy (EGD) and 18F-fluorodeoxyglucose/computed tomography (FDG-PET/CT) and to discuss the utility of these examinations.

MATERIAL AND METHODS

Between September 2005 and September 2010, 33 patients with newly diagnosed HPC (all with squamous cell carcinoma) underwent EGD (after a conventional endoscopy, iodine staining was performed) and FDG-PET/CT examinations. We evaluated the prevalence of esophageal cancer among HPC patients according to the EGD findings and determined the sensitivity of FDG-PET/CT for the detection of esophageal primary tumors for each clinical T classification.

RESULTS

In 17 of the 33 patients (51.5%), 29 biopsy-proven esophageal squamous cell carcinomas were diagnosed using EGD. In eight of the 17 (47.1%) patients, two or more esophageal cancer lesions were diagnosed. Twenty-four of the 29 (82.8%) lesions were superficial esophageal cancers, and the remaining five (17.2%) lesions were advanced esophageal cancers. In six of the 29 (20.7%) esophageal cancer lesions that were detected using FDG-PET/CT, only one of the 29 (3.4%) lesions was evaluated as being equivocal; the remaining 22 (75.9%) lesions were not detected. The distribution of the clinical T classifications detected using FDG-PET/CT was as follows: T1a, 0/21 (0%); T1b, 1/3 (33%); and T3, 5/5 (100%).

CONCLUSIONS

The prevalence of esophageal cancer during the pretreatment of HPC patients was 51.5%; this prevalence was higher than that in previous reports. We believe that the increasing proportion of superficial lesions (82.8%) detected using iodine staining and EGD may have led to the relatively high prevalence. FDG-PET/CT detected only 20.7% of the esophageal cancers, although FDG-PET/CT is capable of detecting unexpected primary malignant tumors other than esophageal cancer.

Reliability of and indications for pericranial flaps in anterior skull base reconstruction

Owing to changes in the treatment of skull-base tumors, such as perioperative radiotherapy and advances in approaching the skull base, the use of pericranial flaps should be reconsidered. Therefore, we reviewed the reliability of and indications for pericranial flaps in 26 cases in terms of patient background, the effects of preoperative and postoperative treatment, and the pattern of blood circulation. Flaps were harvested as 25 anteriorly based and 4 laterally based. As a result, postoperative complications were observed in 4 patients. No other risk factors, except for heavy smoking, were observed relative to patient background. Sixteen patients had perioperative radiotherapy, and complication rate was significantly higher in patients with preoperative radiotherapy than patients without preoperative radiotherapy (P=0.014). However, no complications, such as cerebral spinal fluid leakage and intracranial infection, were observed in patients receiving postoperative radiotherapy. Laterally based pericranial flaps had a high complication rate (25%), but it was not significantly higher than anteriorly based flaps (P=0.467). Five anteriorly based flaps were harvested with less feeding vessels as usual because of applying dismasking flap approach, but it did not lead to increasing in complication rate. We conclude that a pericranial flap can be used for skull base reconstruction even if postoperative radiotherapy is planned but might be avoided for patients who have received preoperative radiotherapy. In addition, particular care and flap design should be taken to preserve sufficient vascularity when pericranial flaps are raised as laterally based and less feeding vessels as usual.

Surgical management of large juvenile nasopharyngeal angiofibroma invading the infratemporal fossa with intracranial extradural parasellar involvement in an 8-year-old boy

We present a rare case of a large juvenile nasopharyngeal angiofibroma (JNA) in an 8-year-old boy. Preoperative imaging revealed that the tumor had widely extended to the sphenoid sinus, infratemporal fossa, and cavernous sinus. Following embolization of the feeding vessels, the tumor was successfully removed by a combination of an orbitozygomatic approach and Le Fort I osteotomy under frontolateral craniotomy. An endoscope assisted in the surgery. At 15 months follow-up, the patient was free of the disease with no facial palsy, scars, or malocclusion. JNA is a benign tumor that typically affects adolescent males and is rarely observed during prepuberty. Complete removal of JNA by surgery, the initial therapy, is generally required. However, as in the present case, a large JNA with wide extension requires extended surgery, and such a surgery is more invasive for prepubertal patients. Using an appropriate combination of surgical approaches, a large JNA developed during prepuberty can be safely removed with reduced morbidity.

Ultrastructual morphology of juvenile psammomatoid ossifying fibroma

We investigated the ultrastructural morphology of the hard tissue in a fibro-osseous lesion. Bone samples were obtained from a juvenile psammomatoid ossifying fibroma and were observed under a scanning electron microscope. The lesion had a spongy lamellar structure containing bony tissue. On histological examination, resorbing preexisting lamellar bone associated with a large number of cathepsin K-positive osteoclasts was confirmed. Scanning electron microscopy revealed the bony material to have a cribriform structure and to indicate resorption related to osteoclasts throughout the tumor. These characteristic findings revealed the presence of active bony reconstruction and destruction in this lesion. The spongy calcified structure observed by scanning electron microscopy expressed the characteristic ground glass appearance in computed tomography of this patient. This remarkable activation of osteoclasts may deeply relate to characteristic calcified structure in this lesion. Observation of hard tissue structure under a scanning electron microscope may shed light on the pathology of fibro-osseous lesions in the head and neck.

Anteriorly based pericranial flap: an anatomic study of feeding arteries

The purpose of this study was to obtain anatomic data on the branching levels of the deep branches of the supraorbital artery (SoA) and of the supratrochlear artery (StA) in pericranial flaps. Ten preserved cadavers were used for this study. Each vessel was identified on 12 sides. The deep branch of the SoA had a larger caliber than that of the StA in seven of nine sides. The branching level of the deep branch of the SoA was cephalad to that of the StA on six of nine sides. The deep branch of the SoA diverged shortly after emerging from the supraorbital foramen or notch. However, there were a few cases in which the branch originated at a distance of a few millimeters before or after the foramen or notch. From a practical standpoint, dissection of this pericranial flap below the level of the supraorbital ridge is not advised, and preservation of both feeding arteries is encouraged in order to establish abundant vascularity for this flap.