Surgical Outcome of Extracapsular Dissection of Benign Parotid Gland Tumor: A Comparative Study to Superficial Parotidectomy

Background/Objectives: Extracapsular dissection has the advantage of reducing complications by minimizing tissue loss of the parotid without intentionally exposing the facial nerve in patients with benign parotid tumor. However, there has been controversy over the surgical results. Thus, the surgical outcomes of extracapsular dissection for benign parotid tumor was compared to those of superficial parotidectomy.Materials & Methods: A retrospective chart review was conducted with 132 patients who received surgery for benign parotid tumor in our center from January 2014 to December 2018 retrospectively.Results: A total of 132 people were enrolled, with 62 people receiving extracapsular dissection, 38 people receiving partial superficial parotidectomy and 32 people receiving superficial parotidectomy. No significant difference was found between the three groups regarding complications such as facial nerve palsy, Frey's syndrome, or first bite syndrome. Operation time and hospital stay was significantly short in extracapsular dissection group.Conclusion: For well-selected cases, extracapsular dissection can be considered as an option for surgery of benign parotid tumor.

DIAGNOSTIC ACCURACY OF COLOR ANDPULSED DOPPLER IN THE EVALUATION OF PAROTID GLAND TUMORS

Background: The parotid glands are the largest salivary glands in humans and are frequently involved in various primary & systemic disease processes. The most common benign parotid gland tumor is pleomorphic adenoma. Around 20% of parotid tumors are malignant with most common parotid tumors being mucoepidermoid carcinoma and adenoid cystic carcinoma. Objective: To determine the diagnostic accuracy of pulsed and color Doppler for the evaluation of parotid gland cancer. Methods: It was a cross sectional study by design carried out in Department of Radiology and Department of Maxillofacial Surgery, Mayo Hospital – Lahore in a duration of three year. All the patients were examined with mind-ray 7.5 MHz linear transducer. There are three methods used collectively; Grey Scale, color Doppler and Pulsed Doppler in sonographic examination. Color Doppler and pulsed Doppler demonstrate number of blood vessels within the tumor, their Peak Systolic Velocity and Resistive Index respectively. Histo-pathological results were correlated post operatively with the data obtained from Doppler ultrasound. Data was analyzed using SPSS 23.0 Results: In this study, 192 patients were included .The mean age was 39.42 ± 11.93 years. 58.85% (112) were male patients and 41.15 %( 80) patients were females. The solid masses with regular margins were evaluated and the diagnostic accuracy of pulsed Doppler was found to be 87.5% taking histopathology as gold standard. Conclusion: This study shows pulsed Doppler to be more accurate tool for diagnosis of parotid gland tumor as compared to color Doppler taking histopathology as gold standard.

Transoral Excision of a Large Accessory Parotid Gland Tumor

Accessory parotid gland (APG) tumors account for 1% to 7% of all parotid gland neoplasms but are more likely to be malignant than main parotid gland tumors. Management of APG neoplasms entails surgical excision. Four primary approaches to resection have been described in the literature with varying facial nerve outcomes. We report a case of a 4-cm APG pleomorphic adenoma utilizing a transoral approach for excision without postoperative facial nerve injury. A transoral approach is known to mitigate patients’ cosmetic concerns; however, prior reports utilized endoscopic assistance on patients with smaller tumors. We conclude that large APG tumors can be excised through a transoral approach without undue risk to the distal facial nerves, though this transoral approach ultimately may not be appropriate for malignant neoplasms or difficult dissections.

Improving Parotid Gland Tumor Segmentation and Classification Using Geometric Active Contour Model and Deep Neural Network Framework

Manual assessment of parotid gland status from magnetic resonance imaging is a subjective, time consuming and error prone process. Automatic image analysis methods offer the possibility to get consistent, objective and rapid diagnoses of parotid gland tumor. In this kind of cancer, a large variety in their characteristics, that brings various difficulties for traditional image analysis methods. In this paper, we propose an automatic method to perform both segmentation and classification of Parotid gland region in order to give quantitative assessment and uniform indicators of PGs status that will help pathologists in their diagnostic. The experimental result illustrates the high accuracy of the results of the proposed method compared to the ground truth. Furthermore, a comparative study with existing techniques is presented in order to demonstrate the efficiency and the superiority of the proposed method.

Evaluation of benign tumors of large salivary glands according to the new classification of the European Salivary Gland Society

Introduction: Tumors of large salivary glands constitute about 2-3% of all head and neck tumors. Their incidence is statistically greater in males than in females, with the first symptoms usually appearing between the 4th and 7th decade of life. Material and methods: The aim of the study was to assess the usefulness of the new classification proposed by ESGS in comparison with the divisions of procedures previously valid in the literature, making a retrospective analysis of patients operated due to benign tumors of large salivary glands in the Department of Otolaryngology, Head and Neck Oncology of the Medical University of Lodz in 2012-2020. The retrospective examination was based on the material consisting of: surgical protocols, histopathological results, imaging results and clinical observations. Results: The material includes 283 patients (141 women and 142 men): 249 patients with parotid gland tumor and 34 patients with submandibular gland tumor. The most common histopathological diagnosis was pleomorphic adenoma, which was found in 105 patients (42.17%) and adenolymphoma diagnosed in 94 patients (37.75%). The most common type of surgery was superficial parotidectomy including total superficial parotidectomy in 86 patients (34.54%) and partial superficial parotidectomy in 49 cases (19.68%). Then, according to the frequency of surgery, extracapsular tumor dissection (ECD) was performed (91 patients - 36.55%). According to the ESGS classification, in most cases parotidectomy I, II (37.34% of all parotidectomies) and parotidectomy II (28.49%) were performed. In case of ECD, all tumors were located at level II. Conclusions: In summary, the new classification is aimed at unifying, but also simplifying the current nomenclature, reducing the existing nomenclature errors. By determining the exact location and extent of the tumor within the parotid gland, it facilitates postoperative monitoring of patients by ENT doctors and those of other specialties. Key words: ESGS classification, parotid gland, parotidectomy, extracapsular tumor dissection

Comprehensive analysis of the transcriptome‐wide m6A methylome in invasive malignant pleomorphic adenoma

Background Invasive malignant pleomorphic adenoma (IMPA) is a highly invasive parotid gland tumor and lacks effective therapy. N6-Methyladenosine (m6A) is the most prevalent post-transcriptional modification of mRNAs in eukaryotes and plays an important role in the pathogenesis of multiple tumors. However, the significance of m6A-modified mRNAs in IMPA has not been elucidated to date. Hence, in this study, we attempted to profile the effect of IMPA in terms of m6A methylation in mRNA. Methods Methylated RNA immunoprecipitation with next-generation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) were utilized to acquire the first transcriptome-wide profiling of the m6A methylome map in IMPA followed by bioinformatics analysis. Results In this study, we obtained m6A methylation maps of IMPA samples and normal adjacent tissues through MeRIP-seq. In total, 25,490 m6A peaks associated with 13,735 genes were detected in the IMPA group, whereas 33,930 m6A peaks associated with 18,063 genes were detected in the control group. Peaks were primarily enriched within coding regions and near stop codons with AAACC and GGAC motifs. Moreover, functional enrichment analysis demonstrated that m6A-containing genes were significantly enriched in cancer and metabolism relevant pathways. Furthermore, we identified a relationship between the m6A methylome and the RNA transcriptome, indicating a mechanism by which m6A modulates gene expression. Conclusions Our study is the first to provide comprehensive and transcriptome-wide profiles to determine the potential roles played by m6A methylation in IMPA. These results may open new avenues for in-depth research elucidating the m6A topology of IMPA and the molecular mechanisms governing the formation and progression of IMPA.

The impact of accurate documentation of parotid tumor operative reports on secondary surgical procedure

Objective: To develop a comprehensive operative report schema based on the accuracy of primary operative reports (OpR) assessed on a department’s experience with parotid gland tumor re-operations. Design: Retrospective cross-sectional study. Setting: A tertiary referral center, the Department of Otolaryngology and Laryngological Surgery, Poznan University of Medical Sciences, Poland from 2008 to 2017. Subjects: Out of 1154 surgeries, 71 patients underwent reoperation. Their OpR were categorized into accurate and non-accurate, and re-operation field and re-operation course were categorized as anticipated or unanticipated, according to defined criteria. Intervention: None Main outcome measures: The impact of accuracy of the first OpR on re-operation course. Results: In this series, OpR were 39% (14/36) accurate, 61% (22/36) non-accurate. Re-operation fields were 16% (11/71) anticipated, 37% (26/71) unanticipated. Re-operation courses were 37% (26/71) anticipated, 63% (45/71) unanticipated. An anticipated re-operation course followed 20% (5/26) of accurate and 20% (5/26) of non-accurate primary OpR. An unanticipated re-operation course followed 20% (9/45) of accurate and 40% (18/45) of non-accurate OpR. There is no significant relationship between the re-operation course and accuracy of the first OpR (Chi2(1)=0.69; p=0.40466). The most common variable that affected non-accuracy of the OpR was facial nerve function after surgery (6/12). Conclusions: The operative report should be based on clear criteria, robust classification and comprehensive protocol. This will improve follow-up and facilitate the planning of re-operation.