Pleomorphic adenomas: post-operative radiotherapy is unnecessary following primary incomplete excision: a retrospective review

Clinicopathologic Characteristics and Prognostic Factors of Primary and Recurrent Pleomorphic Adenoma: A Single Institution Retrospective Study of 705 Cases

Although pleomorphic adenoma (PA) is benign, it may recur and prompt further treatment with radiotherapy (RT). This study investigated the prognostic features of primary and recurrent PAs. A total of 705 PAs (613 primary and 92 recurrent) were analyzed. The following parameters: age, site and size, status of resection, histologic features, and clinical management were documented and correlated with recurrence-free survival. For primary PAs: The mean patient age was 50 years (female/male: 2/1), the median size was 2.1 cm (range: 0.5 to 9.0 cm), and the most common location was the parotid (92%). Tumors showed the following: complete encapsulation (25%), involvement of the surrounding salivary gland/fat (74%), hypercellularity (26%), ≥10 pseudopods (15%), squamous metaplasia (43%), mitoses (49%), intravascular tumor deposit (n=1), close proximity to nerves (n=2), positive margin (15%), and suboptimal resection (2%). The recurrence rate was 3.4% and malignant transformation was <1%. On univariate analysis, age below 30, mitosis ≥3/10 HPFs, squamous metaplasia, hypercellularity, and suboptimal resection correlated with recurrence-free survival. On multivariate analysis, only age below 30, mitosis ≥3/10 HPF and suboptimal resection predicted recurrence. For recurrent PAs: The resected primary PAs were fragmented in 58%. Forty-eight percent of patients had subsequent recurrences, mostly within 10 years, and 1 patient developed a subsequent malignant transformation. Forty-two percent of patients received RT. On univariate analysis, only RT was associated with better outcome (P=0.033). Young age, high mitoses, and specimen integrity predicted recurrence in primary PA. Recurrent PAs are difficult to eradicate, and 48% of these recurred for the second time, mostly within 10 years.

An institutional review of recurrent pleomorphic adenoma of the parotid gland

OBJECTIVE

Surgical resection is standard treatment for pleomorphic adenoma (PA) of the parotid gland. A small number (2-5%) of these tumors recur. Recurrence usually necessitates reoperation, which is technically challenging and puts the facial nerve (FN) at risk. The aim of this study is to characterize the recurrent parotid PA population and compare outcomes after surgery for singly recurrent and multiply recurrent tumors.

METHODS

This study was a retrospective chart review of patients at a single tertiary care academic medical center who underwent operations for recurrent PA of the parotid gland between 2007 and 2020. Demographic data, details of surgical interventions, pre- and postoperative FN function, and recurrence rates were studied. These factors were compared between patients with singly and multiply recurrent tumors.

RESULTS

Thirty-eight patients met criteria: 4 patients presented for primary PA and subsequently recurred, 26 with a first recurrence, 7 with a second recurrence, and 1 with a fourth recurrence. Multiply recurrent PAs were more likely to require at least partial nerve sacrifice at the time of reoperation (P = 0.0092). Significantly worse long-term FN outcomes were seen following surgery for multiply recurrent PA (P = 0.008). There was no significant difference between the rate of re-recurrence following first revision surgery vs second-fourth revision surgery. Time to reoperation was significantly shorter between the first and second revision surgery than between the primary surgery and first revision (P = 0.0017).

CONCLUSION

Surgery for recurrent PA incurs high risk to the FN, and this risk appears to increase in the setting of multiple recurrences.

Comprehensive characterization of pleomorphic adenoma at intraoral unusual sites

OBJECTIVE

The present study aimed to comprehensively characterize the epidemiologic characteristics, clinicopathologic characteristics, clinical treatments, and prognoses of pleomorphic adenoma (PA) identified at unusual intraoral sites.

STUDY DESIGN

Patients diagnosed with PA in oral and maxillofacial regions at our institution in the past 16 years (2005-2020) were screened from the inpatient disease registry. All data concerning patients with PA found at unusual intraoral sites (defined as intraoral locations except sublingual gland and palate) were retrieved. Previously published cases with adequate clinicopathologic data were collected from PubMed and Embase. Eligible cases were further reviewed and included for statistical analyses.

RESULTS

Among 1039 cases of PA diagnosed at our institution, 52 lesions were found at unusual intraoral sites. A literature review identified another 63 eligible cases from 32 articles. The upper lip was the most common sites for these lesions (n = 57), followed by buccal mucosa (n = 34), tongue (n = 8), lower lip (n = 8), and retromolar area (n = 2). Recurrence and malignant transformation after surgical resection were extremely rare for these lesions.

CONCLUSIONS

PA might rarely develop at uncommon intraoral sites with atypical presentations, thus complicating its early diagnosis. Surgical resection is the major therapeutic strategy for this rare entity and has a favorable prognosis.

Radiation Therapy After Surgical Resection Improves Outcomes for Patients With Recurrent Pleomorphic Adenoma

Purpose

Pleomorphic adenoma is a benign salivary tumor that may recur multifocally. In case series, the benefit of radiation therapy (RT) for recurrent pleomorphic adenoma remains unclear. We hypothesized that the combination of surgery and adjuvant RT reduces risk of subsequent recurrence compared with surgery alone for recurrent pleomorphic adenoma.

Methods and Materials

Patients who received diagnoses of recurrent pleomorphic adenoma between 1980 and 2016 were identified using an institutional pathology database. Medical records were retrospectively reviewed to determine clinical, operative, pathologic, and imaging characteristics. Kaplan-Meier methods were used to estimate local control after surgery, stratified by completeness of resection and receipt of adjuvant RT. The association of variables with risk of subsequent local recurrence was analyzed using Cox proportional hazards model, and variance estimates were calculated to account for multiple recurrences in the same patient. Toxicities were prospectively recorded in a departmental database.

Results

A total of 49 patients presented with at least 1 recurrence, of which 28 were managed with surgery alone, and 21 were treated with surgery and RT. The median follow-up time after the initial recurrence was 48 months (range, 6-531 months). There were 35 subsequent recurrences; 34 after surgery alone and only 1 after surgery with RT. On multivariate analysis, adjuvant RT was associated with decreased risk of recurrence (hazard ratio, 0.09; 95% confidence interval, 0.02-0.41, P = .002), whereas increasing number of prior recurrences was associated with increased risk (hazard ratio, 1.23; 95% confidence interval, 1.13-1.35, P < .001). Common toxicities of RT included dermatitis, xerostomia, and mucositis.

Conclusions

For patients with recurrent pleomorphic adenoma, the addition of adjuvant RT after surgery is associated with a significant decrease in risk of subsequent tumor recurrence.

Guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL), part II: Management of recurrent pleomorphic adenoma of the parotid gland

INTRODUCTION

The authors present the guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL) for the management of recurrent pleomorphic adenoma (RPA) of the parotid gland.

METHOD

A review of the literature was performed by a multidisciplinary task force. Guidelines were drafted, based on the articles retrieved and the work group members' individual experience. There were then read and re-edited by an independent reading group. The proposed recommendations were graded A, B or C on decreasing levels of evidence.

RESULTS

Complete resection under neuromonitoring is recommended in case of RPA. The risks of progression and malignant transformation, which are higher the younger the patient, have to be taken into consideration. The risk of functional sequelae must be explained to the patient. MRI is recommended ahead of any surgery for parotid RPA, to determine extension and detect subclinical lesions. Radiotherapy should be considered in case of multi-recurrent pleomorphic adenoma after macroscopically complete revision surgery at high risk of new recurrence (microscopic residual disease), in case of RPA after incomplete resection, and in non-operable RPA.

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.

Current thinking about the management of recurrent pleomorphic adenoma of the parotid: a structured review

Pleomorphic adenoma is the most common tumour of the parotid gland, and can recur after excision. Recurrent pleomorphic adenoma can be a challenge to treat, and has variable outcomes. The aim of this review was to summarise current thinking in its management, which may be helpful to clinical teams and could improve patients' health-related quality of life. We searched several online databases using the key terms pleomorphic adenoma, recurrent pleomorphic adenoma, parotid gland tumours, parotid surgery, radiotherapy and parotid pleomorphic adenoma, and parotid surgery outcomes. Information collected included sample size, recurrence rate, condition of the facial nerve, type of operation, adjuvant treatments associated with recurrence, and clinical outcome. We screened 2301 papers, of which 49 were eligible. There was no consensus among authors about management. There are few if any randomised studies, and so conclusions in most papers were based on coherent arguments. Pleomorphic adenomas of the parotid tend to recur after long intervals, with a propensity towards multifocal disease, and the risk of recurrence (which depends on the initial surgical technique) is higher when the initial operation was done at a young age, after enucleation, and if the initial margins were invaded. Published conclusions suggest that the accepted management varies from observation in selected cases to total parotidectomy with or without postoperative radiotherapy.

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.