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.

Characteristics and Outcomes of Parotid Gland Tumors in Adolescents

Objective Parotid tumors are rare neoplasms in adults but are exceedingly infrequent in adolescents. We aimed to determine the clinical characteristics and outcomes of parotid tumors in adolescents under 20 years old. Methods Between 1999 and 2020, 979 cases of benign parotid tumors and 236 cases of malignant parotid tumors were treated surgically in our department. Of these, 12 benign cases (1.2%) and 9 malignant cases (3.8%) were in adolescents. There were no benign or malignant cases for those aged under 10 years. Results Regarding the histological type, all benign tumors were pleomorphic adenomas. About half of malignant tumors were mucoepidermoid carcinomas, and excluding one high-grade case, the grade of malignancy was all low/intermediate. The accuracy of fine-needle aspiration cytology among adolescents showed no significant difference with that of adults. In contrast to adults, adolescent benign tumor cases showed a markedly high rate of pleomorphic adenomas and no postoperative facial nerve palsy. Malignant tumors in adolescents had a different trend than adults; low/intermediate-grade malignancies were common and thus few symptoms/signs of malignancy could be observed. As well, the accuracy of fine-needle aspiration cytology was poor. All cases had a good prognosis and are disease-free survival. Conclusion Parotid tumors in adolescents are rare but have several characteristics that are distinct from adults. As long-term observation is required posttreatment in adolescent patients, recurrence in benign pleomorphic adenomas and poor long-term prognosis in malignant tumors, especially for those with low/intermediate-grade malignancy, are more likely to be observed.

Pleomorphic Adenoma of Neck: Case Report

Pleomorphic adenomas are benign tumour of the salivary glands that mostly affect the parotid gland. The tumor's "pleomorphic" form can be explained by its epithelial and connective tissue origins. Females between the ages of 30 and 50 are more likely to get the tumour. The tumour usually presents as asymptomatic swelling that progresses slowly. The majority of treatment is surgical removal of the tumour mass, with special attention paid to preserving the facial nerve. This is a case report of a 42-year-old female patient who had a pleomorphic adenoma of the submandibular gland. On the right side of the face, the patient had a slowly growing asymptomatic swelling. Pleomorphic adenoma is the commonest salivary gland tumor characterized by diverse histomorphological features. Early diagnosis and treatment plan entails thorough history taking, clinical examination, coupled with radiographic and histopathological findings.

Rupture of the Pleomorphic Adenoma of the Parotid Gland. What to Know before, during and after Surgery

Background: We assessed the cases of intraoperative spillage of primary pleomorphic adenomas (PPAs) of the parotid gland in the literature, comparing them with our own cases. We aim to explain how the surgeon should manage a spillage during surgery (i.e., how to avoid spreading the contents that are coming out of the tumor). We also aim to investigate whether or not spillage is linked to a higher rate of PPA recurrence. Methods: We collected surgical and pathological reports, taking data on capsular ruptures and the spillage of tumors. Results: Intraoperative tumor spillage and tumor rupture occurred in 34/202 cases. There were three recurrences after a mean of 3.7 years (mean follow-up duration: 10.3 years). One recurrence happened to a patient who had an intraoperative tumor spillage, and two more recurrences happened to patients who did not have spillage. Conclusion: We believe that the real number of the events of spillage is underestimated and underreported by surgeons. Capsular rupture must always be avoided, and secure resection margins must always be pursued, independent of the type of parotidectomy being performed. Features that increase the risk of recurrence are an intraoperative rupture and the presence of satellite nodules (as recorded in the pathologist’s report). In these cases, patients need a longer follow-up period.

Differentiation of Malignant Salivary Gland Tumors from Pleomorphic Adenomas and Warthin’s Tumors: Combined Diagnostic Value of Tumor Blood Flow and Apparent Diffusion Coefficient by Histogram Analysis

We aimed to evaluate the usefulness of tumor blood flow (TBF) obtained by pseudocontinuous arterial spin labeling (pCASL) and apparent diffusion coefficient (ADC) for differentiating salivary gland malignant tumors (MTs) from pleomorphic adenomas (PAs) and Warthin’s tumors (WTs). We used pCASL imaging and ADC map to evaluate 65 patients, including 16 with MT, 30 with PA, and 19 with WT. We evaluated all tumors by histogram analyses and compared various characteristics by one-way analysis of variance followed by Tukey post-hoc tests. Diagnostic performance was evaluated by receiver operating characteristic (ROC) curve analysis. There were significant differences in the mean, 50th, 75th, and 90th percentiles of TBF among the tumor types, in the mean TBFs (ml/100g/min) between MTs (57.47 ± 35.14) and PAs (29.88 ± 22.53, p = 0.039) and between MTs and WTs (119.31 ± 50.11, p < 0.001), as well as in the mean ADCs (×10− 3 mm2/sec) between MTs (1.08 ± 0.28) and PAs (1.60 ± 0.34, p < 0.001), but not in the mean ADCs between MTs and WTs (0.87 ± 0.23, p = 0.117). In the ROC curve analysis, the highest areas under the curves (AUCs) were achieved by the 10th and 25th percentiles of ADC (AUC = 0.885) for differentiating MTs from PAs and the 50th percentile of TBF (AUC = 0.855) for differentiating MTs from WTs. The AUCs of TBF, ADC, and combination of TBF and ADC were 0.850, 0.885, and 0.950 for MT and PA differentiation and 0.855, 0.814, and 0.905 for MT and WT differentiation, respectively. The combination of TBF and ADC evaluated by histogram analysis helped differentiate salivary gland MTs from PAs and WTs.

Pilot study on the value of Raman spectroscopy in the entity assignment of salivary gland tumors

Background The entity assignment of salivary gland tumors (SGT) based on histomorphology can be challenging. Raman spectroscopy has been applied to analyze differences in the molecular composition of tissues. The aim of this study was to evaluate the suitability of RS for entity assignment in SGT. Methods Raman data were collected in deparaffinized sections of pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC). Multivariate data and chemometric analysis were completed using the Unscrambler software. Results The Raman spectra detected in ACC samples were mostly assigned to nucleic acids, lipids, and amides. In a principal component-based linear discriminant analysis (LDA) 18 of 20 tumor samples were classified correctly. Conclusion In this proof of concept study, we show that a reliable SGT diagnosis based on LDA algorithm appears possible, despite variations in the entity-specific mean spectra. However, a standardized workflow for tissue sample preparation, measurement setup, and chemometric algorithms is essential to get reliable results.

Surgical Approaches to Parapharyngeal Space Tumors: An Example and Review of the Literature

Parapharyngeal space tumors (PPS) are rare. They represent less than 1% of all head and neck tumors. They are of various histologies. Pleomorphic adenomas originating from the parotid (prestylian parapharyngeal space) are the most frequent. We report the case of a 50-year-old patient treated for a pleomorphic adenoma (PA) of PPS. His initial complaints were apnea and dysphagia. The correct diagnosis was preoperatively suspected by magnetic resonance imaging (MRI). The surgery was carried out using two approaches: transoral and cervical transparotid approaches. Definitive histology was consistent with encapsulated pleomorphic adenoma. In the present work, we reviewed clinical, radiological, and histological features of parapharyngeal space tumors. We tried to summarize the common surgical approaches. The chosen approach is, in fact, scheduled taking into account several parameters including tumor volume and purpose of the surgery.

Giant pleomorphic adenoma of the parotid gland: a case report

Pleomorphic adenomas account for the majority of parotid masses, typically arising in the tail of the gland and enlarging slowly. Most are 2 to 6 cm in size when resected. We report the resection of a benign mixed tumour of the left parotid gland with a history of bleeding. The resected tumour measured 21 cm in diameter, weighed 1.81 kg, and on pathologic examination was a benign mixed tumour without malignant degeneration. The implications of this unusual case for the management of mixed tumours are discussed with a review of the literature.

Use of Propensity Score Matching to Compare Short Outcomes from Transoral and External Surgical Approaches in Patients with Deep-Lobe Parotid Pleomorphic Adenomas

To compare the outcomes of patients who had deep-lobe parotid gland pleomorphic adenomas (PAs) that extended into the parapharyngeal space after surgical treatment, using a transoral approach or an external approach. One hundred and twelve eligible patients, with deep-lobe parotid gland PAs, were enrolled in this retrospective study. The surgical outcomes were compared for patients who received a transoral approach and an external approach, using 1:1 propensity score matching (PSM). The outcome measures were recurrence rate, facial nerve deficit, Frey’s syndrome, and hospitalization time. The median follow-up time was 4.8 years. After PSM, the transoral approach and external approach groups had no statistically significant difference in recurrence (10.3% vs. 3.4%; p = 0.201). The transoral approach group had no facial nerve deficit, but 5 of 29 patients (17.2%) in the external approach group had transient facial nerve paralysis (p = 0.052). The external approach group had a longer hospitalization time than the transoral approach group (5 vs. 4 days, p = 0.0017). The use of a transoral surgical approach to treat patients with deep-lobe parotid gland PAs led to low recurrence, shorter hospitalization times, and good functional and cosmetic outcomes.