Pleomorphic adenoma of the parotid: formal parotidectomy or limited surgery?

Utility of fine-needle aspiration biopsy (FNAB) in parotid pleomorphic adenoma diagnosis and management

PURPOSE

Pleomorphic adenoma (PA), the most common benign tumour of the parotid gland, requires accurate preoperative diagnosis owing to its capacity for malignant transformation. The aim of this study was to evaluate our experience with ultrasound-guided fine-needle aspiration biopsy (FNAB) in the diagnostic algorithm for patients with PA and to assess clinical outcomes for those with different surgical approaches.

MATERIAL AND METHODS

We carried out a retrospective analysis of patients treated for parotid gland mass between 2010 and 2016. These had had preoperative FNAB and had undergone subsequent surgery.

RESULTS

165 patients had FNAB with the result of PA and the definitive histology confirmed PA in 159 cases (96.4%). On the other hand, in 179 patients, the definitive histology showed PA and the preoperative FNAB result corresponded in 159 cases (88.9%). The measured sensitivity, specificity and accuracy of ultrasound-guided FNAB in the diagnosis of PA were, respectively, 88.83%, 96.23% and 92.31%. Most of the patients underwent superficial or partial superficial parotidectomy, followed by extracapsular dissection which was associated with statistically lower risk of facial nerve injury (P=0.04).

CONCLUSION

Ultrasound-guided FNAB is simple, accurate and valuable in the diagnosis of PA and provides results that can lead to the choice of less invasive operative treatment.

An ultrasound-based histogram analysis model for prediction of tumour stroma ratio in pleomorphic adenoma of the salivary gland

OBJECTIVES

Preoperative identification of different stromal subtypes of pleomorphic adenoma (PA) of the salivary gland is crucial for making treatment decisions. We aimed to develop and validate a model based on histogram analysis (HA) of ultrasound (US) images for predicting tumour stroma ratio (TSR) in salivary gland PA.

METHODS

A total of 219 PA patients were divided into low-TSR (stroma-low) and high-TSR (stroma-high) groups and enrolled in a training cohort (n = 151) and a validation cohort (n = 68). The least absolute shrinkage and selection operator regression algorithm was used to screen the most optimal clinical, US, and HA features. The selected features were entered into multivariable logistic regression analyses for further selection of independent predictors. Different models, including the nomogram model, the clinic-US (Clin + US) model, and the HA model, were built based on independent predictors using logistic regression. The performance levels of the models were evaluated and validated on the training and validation cohorts.

RESULTS

Lesion size, shape, cystic areas, vascularity, HA_mean, and HA_skewness were identified as independent predictors for constructing the nomogram model. The nomogram model incorporating the clinical, US, and HA features achieved areas under the curve of 0.839 and 0.852 in the training and validation cohorts, respectively, demonstrating good predictive performance and calibration. Decision curve analysis and clinical impact curves further confirmed its clinical usefulness.

CONCLUSIONS

The nomogram model we developed offers a practical tool for preoperative TSR prediction in PA, potentially enhancing clinical decision-making.

Algorithms of follow-up in patients with head and neck cancer in relation to primary location and advancement. Consensus of Polish ENT Society Board and Head Neck Experts

Summary

The algorithm of follow-up in patients with head and neck cancer (HNC) has been prepared by a board of Polish Head Neck and Oncology Experts. The aim of this research is to focus on the specificity of HNC monitoring, to review the current trends in follow-up, and to adapt the evidence-based medicine international standards to the capabilities of the local healthcare service.

Materials and methods

The first methodological step was to categorize HNCs according to the estimated risk of failure after the adequate first-line treatment and according to the possibility of effective salvage treatment, resulting in improved overall survival. The final method used in this work was to prepare an authors' original monitoring algorithm for HNC groups with a high, moderate, and low risk of recurrence in combination with a high or low probability of using an effective salvage.

Results

Four categories were established: Ia. low risk of recurrence + effective organ preservation feasible; Ib. low risk of recurrence + effective salvage feasible; II. moderate risk of recurrence + effective salvage feasible; III. high risk of recurrence + effective salvage feasible; and IV. high risk of recurrence + no effective salvage feasible. Follow-up visit consisting of 1. ENT examination + neck ultrasound, 2. imaging HN tests, 3. chest imaging, 4. blood tests, and 5. rehabilitation (speech and swallowing) was scheduled with a very different frequency, at the proposed monthly intervals, tailored to the needs of the group. The number of visits for individual groups varies from 1 to 8 in the first 2 years and from 1 to 17 in the entire 5-year monitoring period. Group IV has not been included in regular follow-up, visits on own initiative of the patient if symptomatic, or supportive care needs, having in mind that third-line therapy and immune checkpoint inhibitors are available.

Conclusion

Universal monitoring algorithm for HNC four groups with a high, moderate, and low risk of recurrence after the adequate treatment in combination with a high or low probability of using an effective salvage is an innovative approach to redeploying system resources and ensuring maximum benefit for patients with HNC.

Incidence and Possible Predictive Factors of Facial Nerve Paralysis after Superficial Parotidectomy for Benign Tumours: Our Experience

Salivary gland tumors represent 3-10% of all head and neck neoplasms. Most of the tumours are benign with parotid gland being most commonly affected. Surgical intervention in the form of parotidectomy forms the mainstay of treatment. Among the various postoperative complications that may occur after parotidectomy, facial nerve weakness is the most dreaded one for both the surgeon as well as the patient. In the literature, the incidence of transient facial weakness after parotid surgery ranges from 10 to 68%, and long-term dysfunction ranges from 0 to 19%. Apart from injury mechanisms such as nerve division, stretch, thermal injuries, ischemia, several other risk factors such as tumour size, disease duration etc. have also been identified for post parotidectomy facial nerve dysfunction which vary considerably from study to study. Thus, facial nerve injury despite being a common and dreaded complication is also a preventable one. We in our institute conducted a retrospective study from January 2018 to December 2021 to evaluate the incidence of facial nerve weakness and possible predictive factors among 60 patients who underwent superficial parotidectomy for benign tumours and found that when it comes to benign tumours surgical technique rather than tumour factors are more important in preventing nerve injury. Undertaking this study was important in order to emphasize the importance of extensive preoperative planning and better surgical practices among budding head and neck surgeons in our country.

CT based intratumor and peritumoral radiomics for differentiating complete from incomplete capsular characteristics of parotid pleomorphic adenoma: a two-center study

OBJECTIVE

Capsular characteristics of pleomorphic adenoma (PA) has various forms. Patients without complete capsule has a higher risk of recurrence than patients with complete capsule. We aimed to develop and validate CT-based intratumoral and peritumoral radiomics models to make a differential diagnosis between parotid PA with and without complete capsule.

METHODS

Data of 260 patients (166 patients with PA from institution 1 (training set) and 94 patients (test set) from institution 2) were retrospectively analyzed. Three Volume of interest (VOIs) were defined in the CT images of each patient: tumor volume of interest (VOI_tumor), VOI_peritumor, and VOI_{intra-plus peritumor}. Radiomics features were extracted from each VOI and used to train nine different machine learning algorithms. Model performance was evaluated using receiver operating characteristic (ROC) curves and the area under the curve (AUC).

RESULTS

The results showed that the radiomics models based on features from VOI_{intra-plus peritumor} achieved higher AUCs compared to models based on features from VOI_tumor. The best performing model was Linear discriminant analysis, which achieved an AUC of 0.86 in the tenfold cross-validation and 0.869 in the test set. The model was based on 15 features, including shape-based features and texture features.

CONCLUSIONS

We demonstrated the feasibility of combining artificial intelligence with CT-based peritumoral radiomics features can be used to accurately predict capsular characteristics of parotid PA. This may assist in clinical decision-making by preoperative identification of capsular characteristics of parotid PA.

Tratamiento quirúrgico de la patología tumoral de la glándula parótida. Estudio descriptivo de 263 parotidectomías

Introducción y objetivo: Los tumores salivales representan el 3-10% de los tumores de cabeza y cuello, siendo el 75-80% de origen parotídeo y en su mayoría benignos. La parotidectomía es una técnica quirúrgica que consiste en la exéresis de la glándula parótida. Existen diversos tipos; parotidectomía superficial (PS), parotidectomía superficial parcial (PSP) y parotidectomía total (PT). En esta última, al no respetarse el nervio facial (NF), las complicaciones son más frecuentes. Nuestro objetivo es analizar el resultado (tasa de recidiva y complicaciones) de la parotidectomía como técnica quirúrgica empleada en el manejo de la patología parotídea, así como evaluar qué prueba complementaria es la más eficaz en el diagnostico prequirúrgico de la patología parotídea tumoral. Material y método: Se realiza un estudio retrospectivo incluyendo 263 pacientes tratados mediante PS o PT entre enero de 2004 y diciembre de 2020 en el Hospital Universitario de Fuenlabrada. Se registraron datos demográficos, tiempo de evolución de la lesión, pruebas complementarias, protocolo quirúrgico y complicaciones postoperatorias. Se analiza principalmente la correlación positiva entre las pruebas realizadas prequirúrgicas (PAAF, ecografía, TC y RMN), con el diagnóstico definitivo anatomopatológico obtenido tras examinar la pieza quirúrgica. También se describe la tasa de paresia y parálisis facial y otras complicaciones habidas. Resultados: Se incluyeron 263 pacientes tratados mediante parotidectomía. El tiempo de evolución medio de las lesiones parotídeas fue de 15 meses (DE 19.88). La sensibilidad de la PAAF en nuestro estudio fue de 68.7%. Se realizó ecografía en un 44.10% de los pacientes, TC en un 77.94% y RMN en un 15.20%, mostrando una sensibilidad de 18.05%, 31.21% y 45%, respectivamente. La cirugía más frecuente fue la PS (43.3%, 114/263), seguida por la PSP (41.1%, 108/263) y, por último, la menos habitual fue la PT (15.58%, 41/263). Los tumores benignos fueron más frecuentes (84.79%, 223/263), siendo el adenoma pleomorfo el más frecuente, 45.73% (102/223). Dentro del grupo de tumores malignos (15.20%, 40/263), el más habitual fue el carcinoma mucoepidermoide (17.5%, 7/40) y las metástasis (17.5%, 7/40). La paresia facial, según la escala de House-Brackmann, fue leve (grado I y II) y transitoria en la mayoría de los casos, apareciendo en un 31.55%. Tras un periodo medio de seguimiento de 6 años no se han encontrado recidivas post parotidectomía por ningún tipo tumoral en nuestro estudio. Conclusión: En nuestra muestra, los tumores benignos representaron la gran mayoría de la patología parotídea. Dentro de este grupo, el adenoma pleomorfo fue el más frecuente. La PAAF fue la prueba complementaria con mejor correlación con el diagnostico anatomopatológico definitivo, seguida por la RMN. La paresia facial leve (grados I y II) y transitoria fue la complicación postquirúrgica mas habitual.

Diagnostic role of DOG-1, GFAP and B-catenin in Basal cell Adenoma and Cellular Pleomorphic Adenoma of the Salivary Gland

BACKGROUND

Pleomorphic Adenoma (PA) and Basal cell adenoma (BCA) are benign salivary gland tumors that may pose a diagnostic challenge if typical features are not present. Due to the increased relapse and malignant transformation rate of the former, a correct diagnosis carries relevant prognostic information. Even though immunohistochemistry (IHC) plays a limited role in the diagnosis of these tumors, the use of IHC panels could increase diagnostic accuracy. In the present work, we aimed to demonstrate that the use of an IHC panel consisting of Glial Fibrillary Acid Protein (GFAP), B-Catenin and Discovered On GIST 1 (DOG-1) can aid in the differential diagnosis between PA and BCA.

METHODS

We analyzed 18 cases of benign salivary gland tumors (Pleomorphic adenomas and Basal cell adenomas) with overlapping histologic features. First, a head and neck pathologist diagnosed the cases relying on morphology alone. Afterwards, cases were re-evaluated considering the IHC panel results. Inter-observer IHC scoring concordance was evaluated with pre-defined marker cut-off points using Cohen's Kappa scores.

RESULTS

Based on morphology alone, 9 cases were classified as PA while the remaining tumors were considered to be BCA. Five out of nine BCA cases showed GFAP staining and absent nuclear B-catenin and DOG-1 positivity. Conversely, 2 PA cases showed absent GFAP and positive nuclear B-catenin with concurrent DOG-1 expression. Therefore, after IHC evaluation, up to 40% of morphologic diagnoses were reconsidered. Overall, the inter-observer concordance for IHC evaluation was good (resulting Kappa Scores between 0.78 and 1).

CONCLUSION

Our work supports the use of a concise IHC panel to improve the diagnostic accuracy of benign salivary gland tumors with overlapping histologic features.

Pleomorphic Adenoma of the Parotid Gland and the Parapharyngeal Space: Two Diametrically Opposing Surgical Philosophies for the Same Histopathologic Entity?

BACKGROUND

The aim of this study was to investigate the histopathologic findings in parotid and parapharyngeal pleomorphic adenomas and draw conclusions concerning the surgical strategy.

METHODS

Retrospective study of medical charts of patients with resected pleomorphic adenomas (PA) between 2005 and 2020 at two tertiary medical referral centers. Histologic specimens were reexamined by an experienced head and neck pathologist. Patients with insufficient/incomplete data were excluded from our study sample.

RESULTS

A total of 844 patients formed our study sample (291 men, 553 women, average age 48.9 years); 786 cases had a PA in the parotid gland (PG) (93.1%), and the remaining 58 cases had a PA in the parapharyngeal space (PS) (6.9%). Recurrences were detected in 8/844 cases (7/786 in the PG, 1/58 in the PS, 0.94% in total) with a mean follow-up time of 86.7 months (10-189 months) with no statistically significant differences between the study groups (p = 0.527). Our analysis showed that parapharyngeal pleomorphic adenomas are characterized by a lower incidence of an intact anatomical capsule (71.4% vs. 82.6%, p = 0.035) and a remarkably more frequent occurrence of satellite nodules (20.7% vs. 7.5%, p < 0.001).

CONCLUSIONS

The more challenging histopathologic profile of parapharyngeal pleomorphic adenomas points towards the fact that parapharyngeal surgery should remain in the hands of experienced surgeons at high-volume centers.

Increase in Chymase-Positive Mast Cells in Recurrent Pleomorphic Adenoma and Carcinoma Ex Pleomorphic Adenoma of the Parotid Gland

Incomplete excision of pleomorphic adenoma (PA) may result in recurrent pleomorphic adenoma (RPA). Furthermore, long-term neglected PA may become carcinoma ex pleomorphic adenoma (CXPA). In the present study, the relationships between mast cell-derived chymase and these tumors were examined. The tumor tissues of PA consisted of either or both glandular and fibrotic structures. Histological features of RPA were almost similar to those of PA, except that they showed multinodular structures. CXPA is composed of a mixture of PA and carcinoma. The main stromal cells in PA were myofibroblasts, whereas fibroblasts constituted the main cellular portion in the stromal tissue of RPA. Cancer-associated fibroblasts (CAFs) were present abundantly in CXPA. With increased VEGF expression, neovascularization tended to increase in RPA or CXPA. Compared with PA, chymase-positive mast cells, as well as chymase gene expression, were increased in the tumor tissues from patients with RPA or CXPA. SCF, TGFβ1, and PCNA-positive staining was widely observed in these tumor tissues. The above results suggest that mast cell-derived chymase through its direct or cooperative effects with other mediators may participate in the pathophysiology of RPA and CXPA.

Surgical interventions for management of benign parotid tumors: A systematic review and network meta-analysis

The impact of the extent of parotid surgery on postoperative complications has long been considered a topic of controversy. The aim of the current network meta-analysis (NMA) is to answer the following questions: (1) Does the extent of surgical resection of benign parotid tumors increase the risk of postoperative complications? (2) What is the best surgical intervention for treatment of benign parotid tumors that can provide an acceptable balance between tumor recurrence rate and other postoperative complications? A comprehensive search on PubMed, Embase, Scopus, and Cochrane library was conducted to identify the eligible studies. The outcome was the incidence of tumor recurrence, facial nerve weakness (temporary [TFW] or permanent [PFP]), Frey's syndrome (FS), sialocele, and salivary fistula. The Bayesian network meta-analysis (NMA) accompanied by a random effect model and 95% credible intervals (CrI) were calculated using the GeMTC R package. Forty-four studies with a total of 7841 participants were included in the current NMA comparing five surgical interventions, namely enucleation, extracapsular dissection (ECD), partial superficial parotidectomy (PSP), superficial parotidectomy (SP), and total parotidectomy (TP). Enucleation showed the highest recurrence rate compared to ECD, SPS, SP, and TP. No statistical differences were observed concerning the recurrence rate when ECD, PSP, SP, and TP were compared together. There was an increased incidence of TFW and FS with the increase in the extent of parotid resection, while no significant difference was found when comparing enucleation with ECD and PSP. SP showed the highest incidence of PFP, and salivary fistula compared to ECD, PSP, and TP. The tumor recurrence rates in enucleation, ECD, PSP, SP, and TP were 14.3%, 3.6%, 3.7%, 2.8%, and 1.4%, respectively. The current NMA demonstrated that the risk of TFW and FS increases with the increase in the extent of parotid resection and that ECD and PSP can be considered the treatment of choice for benign parotid tumors, as both provide an acceptable balance between the incidence of tumor recurrence and facial nerve dysfunction.

Quantitative dynamic contrast-enhanced MRI and readout segmentation of long variable echo-trains diffusion-weighted imaging in differentiating parotid gland tumors

PURPOSE

To evaluate the ability of quantitative dynamic contrast-enhanced (DCE)-MRI and readout segmentation of long variable echo-trains diffusion-weighted imaging (RESOLVE-DWI) in differentiating parotid tumors (PTs) with different histological types.

METHODS

In this retrospective study, 123 patients with 145 histologically proven PTs who underwent both RESOLVE-DWI and DCE-MRI were enrolled including 51 pleomorphic adenomas (PAs), 52 Warthin's tumors (WTs), 27 other benign neoplasms (OBNs), and 15 malignant tumors (MTs). Quantitative parameters of DCE-MRI (K^trans, K_ep, and V_e) and the apparent diffusion coefficient (ADC) of lesions were calculated and analyzed. Kruskal-Wallis tests with Dunn-Bonferroni correction, logistic regression analyses, and receiver operating characteristic curve were used for statistical analyses.

RESULTS

PAs exhibited a lowest K^trans among these four PTs. WTs demonstrated the highest K_ep and lowest V_e values. WTs and MTs showed lower ADC_min values than PAs and OBNs. The combination of K_ep and V_e provided 98.1% sensitivity, 85% specificity, and 98.7% accuracy for differentiating WTs from the other three PTs. The ADC_min cutoff value of ≤ 0.826 yielded 80.0% sensitivity, 92.3% specificity, and 90.3% accuracy for the differentiation of MTs from PAs and OBNs. K^trans with a cutoff value of ≤ 0.185 achieved a sensitivity, specificity, and accuracy of 84.3, 70.4, and 79.5%, respectively, for discriminating PAs from OBNs.

CONCLUSION

The combination of quantitative DCE-MRI and RESOLVE-DWI is beneficial for characterizing four histological types of PTs.

Giant deep lobe parotid tumor removal via total parotidectomy without mandibulotomy. A simple and safe technique

The transmandibular route is often combined with the transparotid-transcervical approach when extensive surgical field exposure is required, as in the case of deep parotid lobe tumors measuring over 4 cm in size. This procedure implies great morbidity and prolongs surgery time. Furthermore, in cases where additional lip division is performed, the aesthetic outcomes may be poorer. A description is made of the technique used for the removal of giant pleomorphic adenomas of the parapharyngeal space, without mandibulotomy.

Key words:Parapharyngeal space tumor, pleomorphic adenoma, transcervical-transparotid approach, transmandibular approach.

Prevention of Frey's Syndrome with the Use of Porcine Dermal Collagen Graft: Retrospective Analysis of 76 "Formal" Parotidectomies for Benign Pathologies

BACKGROUND

Frey's syndrome is a well-known complication of parotid surgery; its prevention may be achieved by the use of an interpositional barrier between the overlying flaps and the exposed parenchymal bed of parotid gland. The aim of this study was to retrospectively evaluate clinical outcomes with and without the interpositional placement of a porcine dermal collagen graft (PDCG) for prevention of syndrome occurrence.

METHODS

We conducted a 20-year retrospective study including the patients who had undergone "formal" (superficial, total, or subtotal) parotidectomies for benign pathologies. The inclusion criteria also involved patients that were (i) regularly monitored about clinical symptoms related to syndrome, and (ii) examined with Minor starch-iodine test. The severity of the diagnosed syndrome was retrospectively evaluated according to the grading score system of Luna-Ortiz. To assess group differences in terms of the extent of dissection in operating sites, we estimated the tumor and histological specimen volumes using the available dimensions.

RESULTS

We included 73 patients who had undergone 76 formal parotid surgeries. The surgical sites were divided into 2 groups: (1) Group A consisted of 44 sites that were reconstructed with a SMAS flap, and (2) Group B, comprised 32 sites where a PDCG was additionally applied as an artificial preventive barrier. At a mean follow-up of 26.3 months, a significantly lower incidence of clinically diagnosed Frey's syndrome was found after the use of dermal collagen interpositional barrier (P = .031). Specifically, subjective symptoms were reported at an incidence of 31.8% in Group A and 6.7% in Group B. Minor's test was positive at an incidence of 59.09% in Group A and 21.87% in Group B (P = .004, 95% CI). Severe Frey's syndrome was observed in 31.82% of the patients of Group A and in 3.12% of the patients of Group B (P = .002, 95% CI). Since there were no statistical significant differences between the volumes of the removed tumors and the excised histological specimens, the extent of dissection was not proved to influence the occurrence of Frey's syndrome in the compared groups.

CONCLUSION

Porcine dermal collagen is a safe, practical, and useful means for parotid reconstruction, since it seems to contribute in prevention of Frey's syndrome when increased amount of glandular tissue has to be removed. Additional randomized controlled studies with bigger samples are required to better assess the PDCG use in parotid surgery.

Guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL), part I: Primary treatment of pleomorphic adenoma

INTRODUCTION

The authors present the guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL) for the diagnosis and treatment of pleomorphic adenoma (PA) of the salivary glands.

METHOD

A review of the literature was performed by a multidisciplinary task force. Guidelines were drafted based on the articles retrieved and the workgroup members' individual experience. Guidelines were graded A, B, C or expert opinion by decreasing level of evidence.

RESULTS

In clinically suspected salivary gland PA, MRI should be performed, including head and neck lymph node levels. Fine needle aspiration cytology is particularly recommended for tumours difficult to characterise by MRI. Frozen section biopsy should be performed to confirm diagnosis and adapt the surgical procedure in case of intraoperative findings of malignancy. Complete resection of the parotid PA should be performed en bloc, including margins, when feasible according to tumour location, while respecting the facial nerve. Enucleation (resection only in contact with the tumour) is not recommended. For the accessory salivary and submandibular glands, complete en bloc resection should be performed.

Diagnostic value of preoperative fine needle aspiration cytology in parotid gland tumors

BACKGROUND

Salivary gland masses constitute a broad spectrum of lesions ranging from non-neoplastic to benign and malignant lesions. Parotid is the largest salivary gland and constitutes 75% to 80% of all salivary gland areas. 80% of parotid lesions are benign and 20% are malignant.

METHODS

Two-hundred and eight-six patients who underwent aspiration cytology in the pathology laboratory between January 1995 and January 2019, evaluated with a sufficient sample and diagnosed, and subsequently underwent surgical treatment were included in the study.

RESULTS

47.9% (137) of the patients were female and 52.1% (149) were male. The mean age was 58 years (range: 38-84 years). 13 (4.54%) of the cases were evaluated as non-diagnostic, 12 (4.1%) as atypia of undetermined significance, 196 (68.5%) as benign neoplasm, 43 (15%) as suspicious for malignancy, and 22 (7.86%) were evaluated as malignant. In the histopathological examination of the samples prepared from surgical specimens of 13 non-diagnostic cases, seven (53.8%) cases were reported as Warthin tumors, four (30.7%) as pleomorphic adenomas, and two (15.5%) were reported as lymph nodes with intraparotid localization.

CONCLUSION

The diagnosis of Fine needle aspiration cytology (FNAC) in the parotid gland is difficult due to the rarity of malignant salivary gland neoplasms, the diversity of carcinoma types, and the similarity of cytologic findings of benign tumors and low-grade carcinomas. The diagnostic accuracy of preoperative FNAC is high for benign tumors and low for malignant tumors.

Pleomorphic Adenoma of External Auditory Canal: Case Report of First Endoscopic Resection and Literature Review

Ceruminous pleomorphic adenoma is a very rare, mostly benign tumor originating from the ceruminal glands in the external auditory canal. Histologically, it is a mixed tumor with epithelial and stromal parts of different proportions, and is recognized today by the World Health Organization (WHO) as a ceruminous adenoma. Similar to the pleomorphic adenoma of salivary glands, recurrence or malignant degeneration with cellular atypia and metastasis can occur on rare occasions. Here, we describe an 87-year old female patient with a growing spherical mass in the right external auditory canal. After exclusive endoscopic tumor resection, a ceruminous pleomorphic adenoma was histologically diagnosed. Due to the absence of nuclear pleomorphism, no increased mitotic rate, no perineural invasion and no fusion transcripts of the MYB or MYBL1 gene loci, an adenoid cystic carcinoma could be excluded. The postoperative course was without any evidence of complications. A literature review identified 44 articles with 49 patients that were considered. Hearing loss and ear sensations were the most commonly reported symptoms. Most cases underwent an excision via an endaural or retroauricular approach. Recurrences were described in four patients, three of which had a malignant transformation.

Extracapsular Dissection in Pleomorphic Adenomas of the Parotid Gland: Results After 13 Years of Follow-up

OBJECTIVES/HYPOTHESIS

To assess long-term results after the treatment of parotid pleomorphic adenomas (PPAs) using different surgical techniques and focusing on recurrence rates and the risk of adverse effects.

STUDY DESIGN

Retrospective analysis.

METHODS

Retrospective analysis of 182 patients treated exclusively for PPAs at a tertiary referral center between 2000 and 2004. Thorough follow-up examinations over a mean period of 13 years were possible in 53.8% (n = 98/182). Tumors were categorized according to the European Salivary Gland Society (ESGS) system to improve the comparison of outcomes. After different surgical resection strategies, recurrence rates, postoperative facial nerve paresis (FNP), and incidence of Frey's syndrome were assessed. The follow-up period included clinical examinations and imaging of every patient in the treating department.

RESULTS

Of 182 patients, extracapsular dissection (ED) was performed in 29.7%, and other surgical modalities (OSMs), including facial nerve dissection, in 70.3%. After the long-term follow-up, 98% of all the patients (n = 96/98) were recurrence free. When recurrence rates were compared, no significant differences were noted (P < .331). ED resulted in significantly lower FNP rates compared to OSMs (P < .001). FNP rates significantly increased with size and location of the tumors according to ESGS categories (temporary and permanent FNP, P = .04). Surgical invasiveness corresponded to a significant increase in the incidence of Frey's syndrome (P < .001).

CONCLUSIONS

ED was associated with the lowest complication rates, but not with a higher risk of recurrence, when compared with OSM in the long-term course. As ED can be performed in the majority of PPAs, it can be regarded as the treatment of choice whenever possible.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E445-E451, 2021.

Surgical approach to parotid pleomorphic adenoma: a 15-year retrospective cohort study

Our aim was to investigate the clinical outcomes (recurrences, duration of follow-up, and effectiveness) after extracapsular dissection and superficial parotidectomy for pleomorphic adenoma of the parotid gland. We retrospectively studied 261 patients whose adenomas were treated at the Maxillofacial Unit of Magna Graecia University of Catanzaro between January 2003 and December 2015 and had been followed up for at least three years after either extracapsular dissection or superficial parotidectomy. The difference in recurrences and complications between the two techniques were measured by univariate analysis (Fisher's exact test). The level of significance was set at p ≤ 0.05. Of the 261 patients 125 were male (48%) and 136 female (52%), mean (range) age 47 (14-78) years. A total of 210 of the 261 patients had an extracapsular dissection (80%, 101 male and 109 female), and 51 had a superficial parotidectomy (24 male and 27 female). Postoperative complications were recorded in 48 of the 261 patients; complication rate was 10% in the extracapsular dissection group, and a third after superficial parotidectomy. There were more complications in the parotidectomy group (p=0.042). For pleomorphic adenomas located in the superficial portion of the parotid gland, extracapsular dissection is a viable alternative to traditional superficial parotidectomy in the hands of experienced parotid surgeons with regard to clinical outcomes, and it may be superior with regard to cost.

Repeatedly recurring pleomorphic adenoma: a therapeutic challenge

Pleomorphic adenoma (PA) is the most common tumour of the salivary glands, and can recur even after proper surgery. The extent and timing of surgery for recurrent tumours remains controversial, and multiple recurrences pose a special challenge. We evaluated all recurrent PAs (RPAs) treated at the Helsinki University Hospital through 2004-2013 focusing on patients with multiple recurrences. Follow-up data were obtained until January 2018. Of the 47 patients, 70% were women and the median age was 33.5 years. Most of the RPAs were located in the parotid gland (87%), and six (13%) in the submandibular gland. One-third (17/47) of tumours had been primarily excised. This patient population experienced 75 recurrent events in total with two or more recurrences in 14 patients (30%). The time interval between recurrences shortened after each recurrent event and the tumour was more likely to be multifocal. At the end of the follow-up period, 15% had recurrent disease and malignant transformation had occurred in 6%. Treatment for PA and RPA is challenging and requires centralised management. Patients with RPA are often young and recurrences may cause lifelong morbidity, especially when the tumour recurs repeatedly. The utilisation and timing of postoperative radiotherapy needs to be discussed as well as the potential risk for malignant transformation in this patient population.

Analysis of the Clinical Relevance of Histological Classification of Benign Epithelial Salivary Gland Tumours

INTRODUCTION

A vast increase in knowledge of numerous aspects of malignant salivary gland tumours has emerged during the last decade and, for several reasons, this has not been the case in benign epithelial salivary gland tumours. We have performed a literature review to investigate whether an accurate histological diagnosis of the 11 different types of benign epithelial salivary gland tumours is correlated to any differences in their clinical behaviour.

METHODS

A search was performed for histological classifications, recurrence rates and risks for malignant transformation, treatment modalities, and prognosis of these tumours. The search was performed primarily through PubMed, Google Scholar, and all versions of WHO classifications since 1972, as well as numerous textbooks on salivary gland tumours/head and neck/pathology/oncology. A large number of archival salivary tumours were also reviewed histologically.

RESULTS

Pleomorphic adenomas carry a considerable risk (5-15%) for malignant transformation but, albeit to a much lesser degree, so do basal cell adenomas and Warthin tumours, while the other eight types virtually never develop into malignancy. Pleomorphic adenoma has a rather high risk for recurrence while recurrence occurs only occasionally in sialadenoma papilliferum, oncocytoma, canalicular adenoma, myoepithelioma and the membranous type of basal cell adenoma. Papillomas, lymphadenoma, sebaceous adenoma, cystadenoma, basal cell adenoma (solid, trabecular and tubular subtypes) very rarely, if ever, recur.

CONCLUSIONS

A correct histopathological diagnosis of these tumours is necessary due to (1) preventing confusion with malignant salivary gland tumours; (2) only one (pleomorphic adenoma) has a considerable risk for malignant transformation, but all four histological types of basal cell adenoma can occasionally develop into malignancy, as does Warthin tumour; (3) sialadenoma papilliferum, oncocytoma, canalicular adenoma, myoepithelioma and Warthin tumour only occasionally recur; while (4) intraductal and inverted papilloma, lymphadenoma, sebaceous adenoma, cystadenoma, basal cell adenoma (apart from the membranous type) virtually never recur. No biomarker was found to be relevant for predicting recurrence or potential malignant development. Guidelines for appropriate treatment strategies are given.

Parotid pleomorphic adenomas: Factors influencing surgical techniques, morbidity, and long-term outcome relative to the new ESGS classification in a retrospective study

PURPOSE

To assess long-term results after treatment of parotid pleomorphic adenomas (PPAs) with different surgical techniques, standardized according to the European Salivary Gland Society (ESGS) classification system.

METHODS

We analyzed ESGS categories, occurrence of facial nerve paresis (FNP), Frey's syndrome, histopathology, and recurrences. Surgical modalities were compared, differentiating techniques with and without facial nerve dissection. A strict protocol ensured a postoperative follow-up-period of more than 7 years.

RESULTS

205 patients were included. A complete follow-up was possible in 138 patients, 77 of whom underwent extracapsular dissection (ED) and 61 of whom had other surgical modalities (OSMs). ESGS categories correlated with the extent of surgery, significantly with the risk for FNP and Frey's syndrome, but not with recurrences. Recurrences did not differ significantly between ED and OSMs, whereas the risks for FNP (p < 0.001 each) and Frey's syndrome (p = 0.000) were significantly higher after OSMs in comparison with ED. Young women with a stroma-rich (myxoid) tumor subtype appear to have the greatest risk for recurrences.

CONCLUSION

ED is the treatment of choice for PPAs, if possible, resulting in similar recurrence rates but significantly fewer comorbidities in comparison with more extensive surgery. After the treatment of PPAs, a long-term follow-up is needed, including imaging.

Recurrent benign pleomorphic adenoma of the parotid gland: Facial nerve identification and risk factors for facial nerve paralysis at re-operation

OBJECTIVE

Surgery for recurrent pleomorphic adenoma of the parotid gland is challenging since there is a considerable risk of facial nerve injury and a high re-recurrence rate. We investigated surgery for recurrent pleomorphic adenoma, focusing on management of the facial nerve.

METHODS

We reviewed 29 patients who underwent surgery for recurrent benign pleomorphic adenoma of the parotid gland at our department between 1999 and 2018. We examined clinicopathologic features and risk factors for facial nerve injury during reoperation.

RESULTS

Factors associated with difficulty in identifying the main trunk of the facial nerve during surgery were bilobar tumors, multiple tumors, and use of an S-shaped skin incision at the previous operation. When the facial nerve was identified intraoperatively, it could be preserved in 2/3 of patients, while the nerve was only preserved in 1/3 of patients when it was not identified. Factors related to permanent postoperative paralysis included recurrence in the deep lobe or both lobes and multiple tumors.

CONCLUSION

The probability of successfully preserving the facial nerve is relatively high if the nerve can be identified during surgery for recurrent pleomorphic adenoma, although intentional resection is necessary in some patients. Factors associated with difficulty in identifying the facial nerve are similar to those related to permanent postoperative paralysis, including bilobar tumors and multiple tumors. In patients with recurrent pleomorphic adenoma, preservation of the facial nerve is difficult, when they may have undergone previous extensive resection or have multiple tumors requiring subtotal or more extensive resection.

Retrograde approach for parotid benign tumours: A review

INTRODUCTION

Parotidectomy for benign tumours is usually performed after facial nerve trunk discovery through an anterograde approach (AA) of the nerve. More recently, a retrograde approach (RA) toward the facial nerve, which begins on the facial nerve branches and ends on the nerve trunk, has been described. A literature review of the RA was conducted to evaluate the RA and to compare it with AA.

METHODS

A literature review was conducted for the years 1980 through 2016. Nine studies out of 216 were included, including 558 parotidectomies and 370 RA. We studied the operative time (OT), the postoperative complications including facial paralysis (FP), tumour recurrences, and possibilities for reoperation.

RESULTS

Operative time was shorter in RA than in AA. Transitory FP significantly less frequent in RA than in AA in only one studies and not significantly in four studies. Incidence of Frey syndrome was similar in RA and AA. Tumour relapses were reported in 1.8% of cases with RA, comparable to AA.

CONCLUSION

Retrograde parotidectomy is recommendable. OT was significantly shorter for the RA. The FP rate was lower for RA than for AA, but the difference was not significant. The recurrence rate appeared to be similar between RA and AA. Possibilities of reoperation were better after RA.

Contemporary Management of Benign and Malignant Parotid Tumors

To report the standard of care, interesting new findings and controversies about the treatment of parotid tumors. Relevant and actual studies were searched in PubMed and reviewed for diagnostics, treatment and outcome of both benign and malignant tumors. Prospective trials are lacking due to rarity of the disease and high variety of tumor subtypes. The establishment of reliable non-invasive diagnostics tools for the differentiation between benign and malignant tumors is desirable. Prospective studies clarifying the association between different surgical techniques for benign parotid tumors and morbidity are needed. The role of adjuvant or definitive radiotherapy in securing loco-regional control and improving survival in malignant disease is established. Prospective clinical trials addressing the role of chemotherapy/molecular targeted therapy for parotid cancer are needed. An international consensus on the classification of parotid surgery techniques would facilitate the comparison of different trials. Such efforts should lead into a clinical guideline.

The extent of surgery for benign parotid pathology and its influence on complications: A prospective cohort analysis

BACKGROUND

The surgical management of benign parotid tumors is aimed at complete extirpation of the mass with preservation of facial nerve function. There is a relative paucity of literature pertaining to complications after benign parotid surgery and related risk factors. We aim to critically review the outcomes following treatment of benign parotid pathology when surgery entailed either complete superficial parotidectomy (CSP), partial superficial parotidectomy (PSP) or extracapsular dissection (ECD).

MATERIAL AND METHODS

This is a review of prospectively collected data of all parotidectomies performed between June 2006 to June 2016 for histologically-proven benign pathology of the parotid. Median follow-up time was 31.6weeks.

RESULTS

A total of 101 parotidectomies were carried out on 97 patients (40 CSP, 56 PSP and 5 ECD). Pleomorphic adenoma (48.4%) and Warthin's tumors (32.7%) were the most common pathologies. Temporary facial weakness occurred after 7 operations (6.9%). Facial weakness was permanent in 4 cases (3.9%). The rates of sialocele and salivary fistula were 4.9% and 0.9%, respectively. Only one patient (0.9%) developed Frey Syndrome postoperatively. No significant associations between extent of parotid surgery and postoperative facial nerve dysfunction (p=0.674) or wound complications (p=0.433) were observed. Univariate analyses for potential contributing factors such as advanced age, smoking status, tumor location or histology did not demonstrate any increased risk with developing postoperative complications.

CONCLUSION

Partial superficial parotidectomy was associated with low rates of morbidity to the facial nerve and surgical wound. The results were comparable to complete superficial parotidectomy. We recommend offering patient partial superficial parotidectomy where appropriate and this is in line with the current trend of minimising surgical dissection, thereby potentially decreasing the risk of short-term and long-term complications.

Parotid Quadrantectomy Is a Safe Management for Localized Pleomorphic Adenoma

Aim

Pleomorphic adenoma is the most common benign tumor of the parotid gland and is classically treated with superficial or total parotidectomy. Less radical surgeries have been proposed to minimize the risk of facial nerve injury. The oncological safety of these procedures remains controversial. We conducted this study to evaluate the safety of superficial hemi-lobectomy (quadrantectomy).

Patients and methods

Retrospective analysis was conducted on the paraffin sections of archived superficial parotidectomy specimens from 11 male and 6 female patients (median age 33 years). The microscopic extent of extra-capsular extension was determined on pathological revision. In addition, prospective evaluation of 12 quadrantectomy procedures (M/F = 7/5, median age = 36 years) compared to 24 radical surgeries (M = F, median age = 40 years) regarding temporary and persistent facial nerve dysfunction on routine clinical assessment and recurrence rate.

Results

On retrospective pathological revision, pleomorphic adenomata had a median microscopic spread of 3 mm beyond capsule in paraffin sections (SD = 3.6). On prospective analysis with a median follow-up of 33 months (range = 18–54 months), quadrantectomy had similar relative risk of temporary facial nerve dysfunction evaluated at the immediate postoperative period as well as persistent nerve dysfunction assessed at 3 months (P = 0.701 and P = 0.902, respectively). Of the whole study population, one case of recurrence after total parotidectomy was observed at mid-term follow-up (P = 1.000).

Conclusion

Parotid quadrantectomy is a safe management for smaller pleomorphic adenomata localized close to one of the two divisions of the facial nerve.

Mixed Tumor in Deep Lobe and Versatility of Acellular Dermal Matrix

Frey's syndrome and infra-auricular depressed deformities are the ones of the most common complications that can occur after total parotidectomy. We report 1 case of pleomorphic adenoma occurred in the deep lobe that obtained good results from using acellular dermal matrix (ADM) after total parotidectomy. A 24-year-old man visited the hospital with oval shape mass in right mandibular angle which of 4 cm in size was found in the deep lobe of right parotid gland from Magnetic resonance imaging scanning and a pleomorphic adenoma was suspected. A total parotidectomy was performed while preserving the facial nerve. The material known as ADM were placed in the depressed part from where the mass was removed, and the site was sutured. The surgery site was healed well without any complications such as Frey's syndrome or infra-auricular depressed deformities. The pathological result was confirmed as pleomorphic adenoma. In addition to these advantages, it does not have little potential of deformation by the gravity after the surgery, and there is no restraint on circulation, which makes fabrication free and each deformation into various shapes can be described as another advantage of the reconstruction using the ADM.

Why Do Parotid Pleomorphic Adenomas Recur? A Systematic Review of Pathological and Surgical Variables

Background

The recurrence of pleomorphic adenoma (PA) has been extensively debated, mostly in relation to the extent of parotidectomy.

Methods

A systematic review was undertaken to clarify the surgical and pathological variables related to PA recurrence. Inclusion criteria were as follows: English literature, and prospective or retrospective studies. Exclusion criteria were as follows: single case reports, reviews, and lack of PA recurrence data.

Results

Pathology-related variables associated with recurrence include the histological subtype, the thickness and incompleteness of the tumor capsule, pseudopodia, and satellite nodules. Surgery-related variables associated with recurrence are the presence of intact margins and tumor puncture or spillage. Other factors are the size of the tumor and the age of patient. Myxoid subtypes of PA tend to have incomplete and thinner capsules and to recur more frequently. Surgical variables related to recurrence include positive margins and tumor spillage.

Conclusion

Myxoid and/or large PA, especially in young patients, should be approached more cautiously to avoid recurrences.

Benign Parotid Tumors

This article reviews the epidemiology, embryology, risk factors, clinical presentation, diagnostic work-up, and basic management principles for the more common benign parotid neoplasms. The various histopathologies are also discussed and summarized.

Salivary gland pleomorphic adenoma in the Netherlands: A nationwide observational study of primary tumor incidence, malignant transformation, recurrence, and risk factors for recurrence

INTRODUCTION

Whereas salivary gland pleomorphic adenoma (SGPA) is the most common type of salivary gland tumor, little is known about its epidemiology because national cancer registries do not register this disease.

OBJECTIVES

To establish SGPA incidence trends, rates of secondary malignant transformation and recurrence and associated factors in the Netherlands.

MATERIALS AND METHODS

Data on incidence, epidemiology, secondary malignant transformation and recurrence were retrieved from the Dutch pathology registry (PALGA) for the years 1992, 1997, 2002, 2007, and 2012. Multivariate analysis was performed to discover the risk factors for recurrence.

RESULTS

3506 cases of SGPA were recorded implying an overall European standardized rate of 4.2-4.9 per 100,000 person-years. Our figures showed a female preponderance (1:1.43) with an annual 1% rise in female incidence (95% confidence interval [CI]: 0.2-1.8) and a bimodal age distribution in women (p<0.0001). The overall 20-year recurrence rate was 6.7%, and median time to first recurrence was 7years. Positive and uncertain resection margins and younger age at diagnosis were risk factors for recurrence, with odds ratios (ORs) of 4.62 (95%CI 2.84-7.51), 4.08 (95%CI 2.24-7.43), and 0.42 (95%CI 0.29-0.63) respectively. Tumor locations in the minor salivary glands had lower odds of recurrence than tumors in the parotid (OR 0.24; 95% CI: 0.07-0.77; p<0.016). Malignant transformation occurred in 0.15% of SGPAs (3.2% of recurrences).

CONCLUSION

This first nationwide study clearly showed sex differences in SGPA epidemiology, possibly suggesting some underlying hormonal mechanism. Long-term recurrence risks were low, and secondary malignant transformation risks were very low.

Parotidectomy under sedation and locoregional anesthesia with monitoring of brain activity

BACKGROUND

Parotidectomy is usually performed while the patient is under general anesthesia, however, sedation with locoregional anesthesia could be an alternative.

METHODS

Fifteen adult patients with parotid tumors of the superficial lobe were included in this study. Anesthetic procedure consisted of sedation associated with cervical plexus and auriculotemporal nerve block. Sedation was managed based on the bispectral index.

RESULTS

Superficial parotidectomies were performed in 13 patients, and combined partial resections were performed in 2 patients. The mean operative time was 118.2 ± 16.4 minutes. Conversion to general anesthesia was necessary in only 1 patient. Ten surgeries were performed on an outpatient basis. Definitive facial paralysis occurred in 1 patient. All patients reported total satisfaction with the procedure.

CONCLUSION

In selected cases, parotidectomy under sedation plus locoregional anesthesia is feasible and safe. The careful selection of patients and the close collaboration with an anesthesiologist is the key to a successful procedure. © 2016 Wiley Periodicals, Inc. Head Neck 39: 744-747, 2017.

Recurrent pleomorphic adenoma of the parotid gland: Institutional experience and review of the literature

BACKGROUND

Recurrent pleomorphic adenoma (PA) of the parotid gland is a challenging surgical issue with controversy regarding management and long term outcome.

METHODS

All patients who were operated for recurrent PA of the parotid gland between the years 1991 and 2013 were reviewed. Patient demographics, clinicopathologic variables, and operative details were collected retrospectively.

RESULTS

A total of 22 patients were operated for recurrent PA of the parotid gland. Mean interval between recurrences was 7 and 6 years for first recurrence and second recurrence, accordingly. Second recurrence was significantly influenced by younger age at initial treatment (P = 0.009). Only two patients (9%) with a recurrence developed facial nerve paralysis following surgery. Adjuvant radiotherapy was given to nine patients with no evidence of disease progression or recurrence. There were no cases of malignant transformation.

CONCLUSIONS

Recurrent PA of the parotid gland tends to occur in long intervals in a multifocal pattern. Adjuvant radiotherapy could be suggested as an alternative for surgery. J. Surg. Oncol. 2016;114:714-718. © 2016 Wiley Periodicals, Inc.

[Surgical Management for Benign Parotid Tumors: Review of a 16-year Experience with 633 Patients]

OBJECTIVE

The objective of this study was to analyze the diagnosis and postoperative complications of benign parotid tumors for a series of 633 patients who underwent the same diagnostic methods and operation procedure in a single institute.

MATERIALS & METHODS

A series of 633 patients who underwent parotidectomy for benign parotid tumors over a 16-year period was reviewed.

RESULTS

There were 345 female and 288 male patients. The site of the tumors was divided among three groups, superficial, deep, and lower pole tumors. The numbers of each type of above tumors were 342, 122, and 169 cases, respectively. The most common pathology of the parotid tumor was a pleomorphic adenoma (372 cases) followed by a Warthin tumor (166 cases). Pleomorphic adenomas and Warthin tumors accounted for 85% of all benign tumors. The accuracy rate of fine needle aspiration cytology (FNAC) for all benign tumors was 71%, 84% for pleomorphic adenomas and 72% for Warthin tumors. Transient facial nerve dysfunction was observed in 130 patients (21%) in 612 cases of primary benign parotid tumors, and only one patient developed a permanent weakness. The incidence of transient facial nerve dysfunction was 18% in superficial tumors, 39% in deep tumors, and 15% in lower pole tumors. Significant risk factors for development of a transient facial palsy were the site of the tumors, the size of the tumors, operation time, and bleeding volume. Among these risk factors, for the site of the tumors, the deep lobe was the most important factor associated with transient facial nerve dysfunction. Transient facial nerve dysfunction recovered within 6 months in 90% of all cases.

CONCLUSIONS

The accuracy rate of FNAC for benign parotid tumors was 72%. The incidence of transient facial nerve dysfunction in deep tumors was significantly higher compared to that in superficial and lower pole tumors. According to the rate of facial palsy, operation time, and bleeding volume, benign parotid tumor should be divided among three groups, namely superficial, deep, and lower pole tumors.

Charcoal Suspension Tattoo: A New Technique for Intraoperative Detection of Small Tumors of the Parotid Gland

OBJECTIVE

The current surgical trend in the treatment of pleomorphic adenomas of the parotid gland is to limit the extent of resection. This raises the need to correctly identify the mass within the normal parenchyma so as to avoid dissecting the entire superficial lobe of the gland. We describe ultrasound-guided tattooing as a technique to facilitate identification and excision of parotid pleomorphic adenomas.

METHODS

We reviewed 23 consecutive patients with pleomorphic adenoma of the parotid gland. All patients underwent ultrasound-guided tattooing of the lesions with a charcoal suspension. Baseline tumor and patients' characteristics, major and minor complications, and subjective tolerance to the procedure were recorded. We assessed the number of intralesionally marked masses and the percentage of intraoperatively detected marked lesions.

RESULTS

The injection was well tolerated. No major complications were recorded. In 2 cases (9%), a transient increase in lesion size was observed. No other minor complications were encountered. Charcoal was found inside the tumor in 19 cases (83%). In 4 cases (17%), it was found in the tissues above the lesion. Twenty-three lesions were intraoperatively detected (100%) and dissected.

CONCLUSION

Charcoal suspension tattooing is safe and well tolerated for the detection of small pleomorphic adenomas during parotid surgery.

Pleomorphic adenoma of the parotid gland 1985-2010: A Danish nationwide study of incidence, recurrence rate, and malignant transformation

BACKGROUND

Pleomorphic adenoma is the most frequent salivary gland tumor and is known for its tendency to recur and for its ability to transform to carcinoma ex pleomorphic adenoma (Ca-ex-PA). Along with pleomorphic adenoma demographics, we present the first nationwide study with long-term follow-up on these topics.

METHODS

The Danish Pathology Data Bank was searched for parotid pleomorphic adenoma and Ca-ex-PA in the period 1985 to 2010 and all pathology descriptions were reviewed. Ca-ex-PA specimens were reviewed by a pathologist.

RESULTS

A total of 5.497 patients were identified and 2.86% had at least one recurrence. An incidence of 4.29/100,000/year was found. The rate of malignant transformation in recurrent pleomorphic adenoma was 3.3%.

CONCLUSION

We report an up-to-date assessment of the epidemiology of pleomorphic adenoma. We found an increasing incidence and low recurrence rate compared with previous studies. The risk of Ca-ex-PA for patients with recurrent pleomorphic adenoma was low compared to the literature. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1364-E1369, 2016.

Functional Histology of Salivary Gland Pleomorphic Adenoma: An Appraisal

The complex microstructure of salivary gland pleomorphic adenoma is examined in relation to function. Events related to secretion of macromolecules and absorption, responses to the altered microenvironment and controversies concerning epithelial-mesenchymal transition versus modified myoepithelial differentiation are explored. Their effects on tumor cell phenotypes and arrangements are emphasized. Heterotopic differentiation and attempts at organogenesis are also considered. The approach allows interpreting microstructure independently of histogenetic perceptions, envisaging the tumor cells as a continuum, endorsing luminal structures as the principal components, and defining pleomorphic adenoma as a benign epithelial tumour characterized by variable epithelial-mesenchymal transition, secretion/differentiation and metaplasia.

Meta-analysis of surgical approaches to the treatment of parotid pleomorphic adenomas and recurrence rates

INTRODUCTION

Different types of surgical management of pleomorphic adenoma of the parotid gland are associated with different recurrence rates.

MATERIAL AND METHODS

A systematic review of literature until 2014 with meta-analysis was conducted. Inclusion criteria were original studies of patients with surgical management for pleomorphic adenoma of the parotid gland and recurrence rates, with a median follow-up period of 5 years. The Newcastle-Ottawa Quality Assessment Scale (NOQAS) was used to assess the quality.

RESULTS

Sixteen studies were included. Four studies show a low recurrence rate (0.01, 95% confidence interval [CI] = 0.00-0.02) after total parotidectomy. Twelve studies show a low recurrence rate (0.02, 95% CI = 0.01-0.03) after superficial parotidectomy. Six studies show a low recurrence rate (0.02, 95% CI = 0.01-0.04) after limited parotidectomy. Six studies demonstrate a low recurrence rate (0.01, 95% CI = 0.00-0.04) after extracapsular dissection. Five studies report a low-to-medium recurrence rate (0.08, 95% CI = 0.03-0.14) after extracapsular enucleation.

CONCLUSION

Information about recurrence rates, times of recurrence in relation to type of surgical treatment, and significance of capsule rupture is very poor. With regard to recurrence rates and surgical approaches, the types of operations that show the lowest recurrence rate are total parotidectomy and extracapsular dissection. Controversies over surgical treatment of PA of parotid gland remain, and the safest surgical method for the removal of this tumors has not been identified.