Continuing Education Activity

Pleomorphic adenoma represents the most prevalent benign salivary gland neoplasm, accounting for 45% to 75% of all salivary gland tumors and 80% to 90% of benign salivary masses. This course discusses this neoplasm and its dual epithelial and myoepithelial components, which produce marked histologic diversity, with most tumors arising in the superficial lobe of the parotid gland and fewer involving the submandibular or minor salivary glands. Although benign, pleomorphic adenoma carries a risk of local recurrence after incomplete excision and a small but meaningful risk of malignant transformation, underscoring the need for accurate diagnosis and evidence-based management as outlined in this course.

This activity explores pleomorphic adenoma, including the integration of diagnostic reasoning, clinical features, and imaging and biopsy findings effectively in clinical decision-making. Participants will gain an in-depth understanding of tumor presentation across anatomical sites, red flag features requiring urgent evaluation, and current surgical strategies that optimize oncologic control while minimizing morbidity. This activity for healthcare professionals is designed to enhance the learner's competence in identifying pleomorphic adenomas, performing the recommended evaluation, and implementing an appropriate interprofessional approach to manage this condition, thereby improving outcomes for individuals with suspected or confirmed pleomorphic adenoma.

Objectives:

• Evaluate the histopathological features that distinguish pleomorphic adenoma from other salivary gland neoplasms.
• Implement evidence-based surgical techniques, including superficial parotidectomy with facial nerve preservation, to minimize pleomorphic adenoma recurrence rates.
• Assess diagnostic findings of pleomorphic adenomas to determine tumor extent, capsular integrity, and optimal surgical approach.
• Collaborate with interprofessional team members in the management of pleomorphic adenomas to optimize coordinated patient care and postoperative rehabilitation.

Introduction

Pleomorphic adenoma is the most common benign salivary gland neoplasm, constituting approximately 45% to 75% of all salivary gland tumors and 80% to 90% of benign salivary gland masses.[1] This benign mixed tumor derives its name from the histological diversity it exhibits due to its dual epithelial and myoepithelial cellular components. The tumor most commonly involves the superficial lobe of the parotid gland, accounting for 84% of cases; the remainder occur in the submandibular gland (8%) and minor salivary glands (6.5%).[2]

A pleomorphic adenoma, while technically a benign neoplasm, has a propensity for local recurrence if inadequately resected. Furthermore, they rarely undergo malignant transformation, with the most commonly reported risk of 1% per year of developing carcinoma ex pleomorphic adenoma.[3] Understanding the pathophysiology, diagnostic approaches, and evidence-based management strategies remains essential for optimizing patient outcomes while minimizing morbidity associated with surgical intervention.

Etiology

The precise etiology of pleomorphic adenoma remains incompletely understood. Prior exposure to ionizing radiation in the head and neck region is the most well-established environmental risk factor, with latency periods of 15 to 30 years between exposure and tumor development. Occupational exposure to radioactive materials or therapeutic radiation also increases risk. The role of oncogenic simian virus 40 (SV40) in tumor initiation or progression has been suggested, with viral DNA sequences detected in some tumor specimens, though this remains controversial.[4]

Genetic factors play an important role, particularly chromosomal translocations involving the PLAG1 (pleomorphic adenoma gene 1) oncogene, most commonly t(3;8)(p21;q12). Rearrangements affecting the HMGA2 gene and genetic polymorphisms affecting DNA repair mechanisms have also been implicated. Rare cases demonstrate familial clustering, suggesting possible hereditary predisposition. Hormonal influences may contribute to the female predominance, with estrogen-related factors, pregnancy-associated tumor growth acceleration, and hormonal replacement therapy serving as potential risk modifiers.[5][6]

Environmental and lifestyle factors include chronic mechanical trauma or irritation to salivary glands, tobacco use (weak association), and chronic viral sialadenitis as predisposing factors. Autoimmune conditions affecting the salivary glands, eg, Sjögren's syndrome and previous benign salivary gland disease, may also increase the risk.[2]

Epidemiology

Pleomorphic adenoma accounts for up to 75% of all parotid tumors and is the most common salivary gland tumor overall. The incidence ranges from 2 to 3.5 cases per 100,000 population annually, with higher rates observed in North American and European populations than in Asian populations.

The peak incidence occurs in the fourth to sixth decades of life with a median age of 43 years. The rate of malignant transformation increases with advancing age. A female predominance is observed, with a female-to-male ratio of 2:1 to 3:1, becoming more pronounced in minor salivary glands, where females account for up to 75% of cases.[2][7]

Anatomical distribution demonstrates parotid gland involvement in 84% of cases, primarily affecting the superficial lobe. Submandibular gland involvement accounts for 8%, and minor salivary gland involvement accounts for 6.5%, with the palate representing the most frequently affected site. Sublingual gland involvement remains uncommon, occurring in less than 1% of cases. Bilateral disease develops infrequently, affecting fewer than 5% of patients.[2][7]

Pathophysiology

Pleomorphic adenoma typically presents as a slowly enlarging, painless mass with an indolent growth rate averaging 1 to 2 cm over several years. This slow growth pattern allows patients to accommodate the mass, often delaying medical evaluation until the tumor reaches a significant size. The benign nature of the tumor accounts for the absence of pain, facial nerve dysfunction, or systemic symptoms in the vast majority of cases.

The tumor's growth creates a compressed fibrous pseudocapsule around the expanding mass, which gives the clinical impression of encapsulation on imaging studies. However, this pseudocapsule is incomplete and of variable thickness, with microscopic tumor extensions invariably present beyond the apparent tumor boundary. These extensions explain why simple enucleation results in unacceptably high recurrence rates of 15% to 45%, as residual tumor cells remain in the surgical bed.[8] The tumor's tendency to follow tissue planes and ductal structures during growth accounts for its lobulated appearance on imaging and the irregular interface with normal salivary gland tissue.

The relationship between tumor location and clinical symptoms varies significantly. Superficial lobe parotid tumors often present as visible facial masses, with cosmetic concerns being the primary complaint. Deep lobe tumors may cause intraoral fullness, difficulty with dental prosthetics, or changes in voice quality due to involvement of the parapharyngeal space.

The tumor's proximity to the facial nerve determines surgical complexity, with deep lobe tumors requiring more extensive dissection and carrying higher morbidity. Over time, untreated tumors demonstrate progressive growth with increasing risk of malignant transformation, particularly in lesions present for more than 10 to 15 years, explaining the clinical imperative for surgical removal despite the benign histology.[2][7]

Histopathology

Pleomorphic adenomas are surrounded by a fibrous pseudocapsule rather than a true capsule. The tumor infiltrates the surrounding tissue with finger-like projections (pseudopodia) that extend into the normal salivary gland parenchyma. The tumor develops a characteristic vascular pattern, characterized by peripheral vessel compression and central areas of relative hypovascularity, which contribute to its typical imaging appearances and contrast enhancement patterns on cross-sectional imaging.[9]

Microscopic evaluation reveals marked histologic diversity with a biphasic composition of epithelial and myoepithelial cells arranged in multiple architectural patterns (see Image. Pleomorphic Adenoma). Epithelial components form ductal structures, solid nests, and trabecular configurations, with ductal elements typically displaying a double-layered organization composed of an inner cuboidal epithelial lining and an outer myoepithelial layer. Microscopic tumor projections extending through the pseudocapsule consistently appear and represent the leading cause of local recurrence after inadequate excision.

Several histologic characteristics correlate with a higher recurrence risk, including a thin or incomplete pseudocapsule, a dominant myxoid matrix, marked cellular pleomorphism, and zones of increased mitotic activity exceeding 2 mitoses per 10 high-power fields.

History and Physical

Clinical Presentations

The clinical presentation of pleomorphic adenoma varies with anatomical location, tumor size, and symptom duration, requiring systematic evaluation for accurate diagnosis. Patients most commonly present with a painless, slowly enlarging mass that has been present for months to years. The growth pattern is characteristically indolent, with patients often reporting awareness of the mass for extended periods before seeking medical attention.

Furthermore, pain, formication, and facial nerve weakness are uncommon and should raise suspicion for malignant transformation or secondary complications. Red flag symptoms requiring urgent evaluation include rapid tumor enlargement suggesting malignant transformation, facial nerve weakness or paralysis, pain or tenderness, skin involvement or fixation to underlying structures, cervical lymphadenopathy, and trismus or difficulty opening the mouth.[2][7]

Parotid gland presentations typically involve a unilateral, well-defined, mobile mass in the preauricular or infraauricular region. Superficial lobe tumors present as visible and palpable masses, while deep lobe involvement may manifest as intraoral fullness or asymmetry of the soft palate and tonsillar fossa. Facial nerve dysfunction and rapid growth are exceedingly rare in benign pleomorphic adenomas and should prompt investigation for malignant transformation. Submandibular pleomorphic adenomas present as firm, mobile masses in the submandibular triangle, with patients potentially reporting difficulty with mastication or swallowing when tumors reach a significant size.[10]

Minor salivary gland tumors most commonly affect the hard palate, presenting as slowly enlarging, painless masses that may ulcerate with trauma. Symptoms vary by location and may include difficulty with speech, eating, or dental prosthetic retention for palatal tumors, unilateral nasal obstruction, rhinorrhea, and epistaxis for nasal cavity tumors, and cosmetic concerns or difficulty with oral competence for lip tumors.[2][7] Relevant history also includes any history of skin cancers, prolonged sun exposure, and any history of smoking.

Physical Examination

Physical examination should include systematic palpation to assess tumor size, consistency, mobility, and relationship to surrounding structures. Bimanual palpation is essential for submandibular and intraoral lesions. Facial nerve function must be comprehensively evaluated in all parotid masses, including assessment of forehead wrinkling, eyelid closure strength, smile symmetry, and lower lip depression.[2][7]

Evaluation

A comprehensive history and physical examination is often sufficient for evaluating parotid masses, as most are treated surgically. Imaging studies can facilitate biopsies for histologic confirmation and can aid in surgical planning and prognostic discussions, but are not required. If malignancy is clinically suspected, imaging studies are much more relevant.[11] Laboratory studies may occasionally be indicated, primarily to exclude other conditions, eg, Sjögren syndrome.

Ultrasound

Serves as an initial screening tool and biopsy guidance method, typically showing hypoechoic masses with lobulated margins, commonly present posterior acoustic enhancement, variable vascular flow on color Doppler assessment, real-time needle positioning capability for biopsy guidance, and excellent cost-effectiveness for screening and follow-up.[12]

Computerized Tomography

Computerized tomography (CT) provides excellent anatomical detail and tumor localization, typically showing well-circumscribed, lobulated soft-tissue density masses with homogeneous enhancement in smaller tumors and heterogeneous enhancement in larger tumors. Calcifications are present in 5% to 10% of cases, bone involvement is rare and limited to pressure-related changes, and optimal protocols utilize thin-section images with intravenous contrast.[13]

Magnetic Resonance Imaging 

Magnetic resonance imaging (MRI) demonstrates hypointense to isointense appearance relative to muscle on T1-weighted images, markedly hyperintense appearance, especially for myxoid components on T2-weighted images, homogeneous enhancement with possible central hypoenhancement on post-contrast T1 images, capsular rim with low signal intensity on T2-weighted images, and superior assessment of deep lobe extension compared to CT. Advanced techniques include diffusion-weighted imaging, where restricted diffusion may suggest malignancy; dynamic contrast-enhanced MRI with time-intensity curves aiding in characterization; and STIR sequences, which are excellent for detecting perineural tumor spread.[13]

Positron Emission Tomography/Computerized Tomography

Positron emission tomography/computerized tomography (PET/CT) is generally not recommended, as this modality has limited utility in benign tumors. PET/CT is reserved for suspected malignancy or when conventional imaging is inconclusive. Additionally, PET/CT may demonstrate low-grade uptake in pleomorphic adenomas but cannot reliably differentiate benign from malignant lesions.[14]

Biopsy

Fine needle aspiration (FNA) represents the initial tissue sampling method with excellent diagnostic accuracy and minimal morbidity, demonstrating 85% to 95% sensitivity for malignancy detection, 90% to 95% specificity for benign lesion identification, 80% to 90% diagnostic accuracy for pleomorphic adenoma, and less than 0.01% tumor seeding risk when performed by experienced practitioners. Core needle biopsy provides superior histological detail compared to FNA. Furthermore, FNA is increasingly utilized for definitive preoperative diagnosis, offering 95% to 97% diagnostic accuracy, superior histological subtyping, immunohistochemical evaluation with adequate tissue, and a complication rate of less than 1%.[15]

Treatment / Management

The management of pleomorphic adenoma has evolved significantly over the past decades, with contemporary approaches emphasizing complete surgical excision while minimizing functional morbidity and recurrence risk.

Surgical Management

Surgical excision is the treatment of choice for tumors that need treatment.

Parotid tumors

Parotid tumors confined to the superficial lobe measuring less than 3 cm are optimally treated with superficial parotidectomy and facial nerve preservation, achieving local control rates exceeding 95%, facial nerve preservation in over 95% of experienced hands, recurrence rates less than 2% with adequate margins, and operative mortality less than 0.1%. Technical considerations include a modified Blair incision or a face-lift approach for optimal cosmesis, identification and preservation of all facial nerve divisions, complete superficial lobe removal with tumor-free margins, frozen-section analysis of margins when indicated, and facial nerve monitoring to minimize injury risk.

For tumors involving the deep lobe or large superficial lobe masses greater than 4 cm, total parotidectomy may be necessary, requiring facial nerve dissection and preservation throughout all divisions, complete removal of both superficial and deep lobes, reconstruction consideration for facial contour defects, and a higher morbidity risk requiring experienced surgical teams. Deep lobe pleomorphic adenomas present unique surgical challenges, requiring a transcervical-transparotid approach, with possible mandibulotomy for adequate exposure. Attention must be given to the risk of injury to the internal carotid artery and internal jugular vein, as well as cranial nerve monitoring for nerves VII, IX, X, XI, and XII.[16][17][18][19]

Submandibular tumors

Submandibular tumors require complete submandibular gland excision as the standard treatment, utilizing a transcervical approach through a skin crease incision, identification and preservation of the marginal mandibular nerve, preservation of the lingual and hypoglossal nerves, complete gland removal with tumor-free margins, and attention to Wharton's duct identification and ligation.[20]

Minor salivary gland tumors

Minor salivary gland tumors require wide local excision with a 5 to 10 mm margin of normal tissue around the cancer. Full-thickness excision is advised in tumors involving mucosal surfaces. Bone involvement is rare; however, in these cases, periosteal examination is necessary, with primary closure or local flap reconstruction, and frozen-section margin analysis is also recommended. 

Modern surgical techniques emphasize oncological principles, including the no-touch technique to prevent tumor spillage, complete capsular excision with a margin of normal tissue, frozen section evaluation of suspicious areas, copious irrigation in the event of capsular rupture, and thorough inspection and sampling of the tumor bed.[21]

Radiation Therapy

Radiation therapy plays a minimal role in primary pleomorphic adenoma management due to excellent surgical cure rates with appropriate techniques, radiation resistance of benign salivary gland tumors, risk of radiation-induced malignant transformation, and functional impairment of remaining salivary tissue. Rare circumstances where adjuvant radiation may be considered include incompletely excised tumors with positive margins, recurrent disease with limited surgical options, medical contraindications to repeat surgery, and patient refusal of additional surgical intervention.

When used, modern radiation therapy relies on intensity-modulated radiation therapy (IMRT) delivered at doses of 50 to 60 Gy in 1.8 to 2 Gy fractions per day. The target volume encompasses the tumor bed with a 1 to 2 cm margin, while treatment planning prioritizes avoidance of critical structures involving the contralateral parotid, oral cavity, and spinal cord.[22][23]

Differential Diagnosis

Benign Salivary Gland Neoplasms

Benign salivary gland tumors that can have similar clincal presentations to pleomorphic adenoma include:

• Warthin tumor: Male predominance, smoking association, bilateral occurrence, cystic components on MRI. Turbid black fluid on FNA.
• Oncocytoma: Older adult patients, large eosinophilic mitochondria-rich cells, homogeneous enhancement
• Basal cell adenoma: Uniform basaloid cells, smaller size, p63 positive, lacks myoepithelial diversity
• Myoepithelioma: Exclusive myoepithelial proliferation without ductal elements, strong S-100/SMA positivity

Malignant Neoplasms

Malignant tumors that can have similar clincal features to pleomorphic adenoma include:

• Mucoepidermoid carcinoma: Pain, rapid growth, facial nerve involvement, CRTC1-MAML2 fusion
• Adenoid cystic carcinoma: Perineural invasion, "Swiss cheese" histology, high metastatic potential
• Carcinoma ex pleomorphic adenoma: Longstanding tumor with recent enlargement, older adult patients
• Polymorphous adenocarcinoma: Minor salivary glands, uniform cytology with diverse architecture
• Metastasis: Cutaneous squamous cell carcinoma, melanoma

Non-Neoplastic Conditions

Growths that should also be considered in the evaluation of a suspected pleomorphic adenoma include:

• Chronic sialadenitis: Recurrent swelling with eating, ductal dilatation on imaging
• Sjögren syndrome: Bilateral involvement, dry mouth and eyes, positive autoantibodies
• Kimura disease: Asian males, regional lymphadenopathy, elevated IgE, eosinophilia

Prognosis

Complete surgical excision with adequate margins achieves cure rates exceeding 95% for pleomorphic adenoma. Five-year disease-free survival approaches 98%, and 10-year survival remains excellent at 95% to 97%, with most failures due to local recurrence rather than malignant transformation.[24]

Tumor size significantly affects outcomes, with tumors larger than 4 cm demonstrating higher recurrence rates (5%-8% versus 1%-2% for smaller lesions). Patient age represents a critical prognostic factor, as older adult patients older than 60 years demonstrate a 2 to 3 fold higher risk of malignant transformation. The surgical technique employed dramatically influences prognosis, with enucleation associated with 15% to 45% recurrence rates compared to less than 2% with formal parotidectomy.[25]

The risk of malignant transformation to carcinoma ex pleomorphic adenoma is the most serious long-term concern, occurring in 1.5% of cases within 5 years, 9.5% after 15 years, and up to 25% after 20 years. Long-term surveillance remains essential due to the potential for late recurrence, which typically occurs within 5 to 10 years but can also occur decades after initial treatment. Most patients experience excellent functional outcomes with minimal impact on quality of life when treated by experienced surgeons using appropriate techniques.

Complications

Complications specific to pleomorphic adenoma management center primarily on facial nerve injury, tumor recurrence, and malignant transformation. Facial nerve dysfunction represents the most significant surgical risk, occurring temporarily in 15% to 25% of parotidectomy patients and permanently in 2% to 5% when performed by experienced surgeons.[26] Gustatory sweating (Frey syndrome) develops in 10% to 30% of patients following parotidectomy due to aberrant parasympathetic nerve regeneration, typically manifesting 6 to 18 months postoperatively as sweating and flushing during eating.[27]

Local recurrence remains the primary disease-related complication, with rates of 1% to 5% following adequate surgical excision but up to 45% after simple enucleation. Recurrent tumors often present as multifocal masses due to tumor spillage during inadequate initial surgery, complicating subsequent management and increasing facial nerve injury risk. Malignant transformation to carcinoma ex pleomorphic adenoma represents the most serious long-term complication, occurring in 1.5% of cases within 5 years and increasing to 25% after 20 years in untreated tumors.[27]

Additional pleomorphic adenoma-specific complications include great auricular nerve numbness in 80% to 90% of parotidectomy patients, salivary fistula formation in 1% to 3% of cases, and facial depression or asymmetry in 20% to 30% of patients following extensive parotid resection. General surgical complications, eg, bleeding, infection, wound healing problems, and anesthesia-related complications, occur at standard rates for head and neck procedures but are not specific to pleomorphic adenoma surgery.[27]

Deterrence and Patient Education

Patient education regarding pleomorphic adenoma focuses on understanding the benign nature of the tumor while emphasizing the importance of appropriate surgical management to prevent complications. Patients should be informed that pleomorphic adenomas are slow-growing benign tumors that require surgical removal due to the risk of malignant transformation, which increases from 1.5% at 5 years to 25% after 20 years if left untreated. Early recognition and evaluation of neck or facial masses are crucial, as patients should seek medical attention for any persistent, painless, slowly enlarging masses in the salivary gland region.

Preoperative education should include a detailed discussion of surgical risks, particularly those related to facial nerve function, the expected recovery timeline, and the importance of selecting experienced surgeons to minimize complications. Patients must understand that simple enucleation carries unacceptably high recurrence rates of 15% to 45%, making formal parotidectomy the standard of care despite slightly higher morbidity. Postoperative care involves monitoring wounds, restricting activity, and recognizing warning signs, eg, facial weakness, persistent drainage, or signs of infection. Long-term surveillance is essential due to the potential for late recurrence, which necessitates regular follow-up examinations and patient awareness of recurrence symptoms, including the development of new masses, rapid growth, or pain.

Enhancing Healthcare Team Outcomes

Optimal management of pleomorphic adenoma requires coordinated interprofessional care involving head and neck surgeons, pathologists, radiologists, anesthesiologists, and nursing staff working collaboratively to achieve excellent patient outcomes. The core team should include experienced otolaryngologists familiar with facial nerve anatomy and parotid surgery techniques, skilled pathologists capable of accurate histological diagnosis and margin assessment, and radiologists proficient in interpreting salivary gland imaging. Preoperative interprofessional planning through tumor board conferences ensures the selection of an appropriate surgical approach, risk stratification, and patient counseling regarding realistic expectations and potential complications.

Intraoperative team coordination emphasizes facial nerve monitoring, specimen handling protocols, and clear communication regarding critical anatomical structures and margins. The surgical team must maintain standardized safety checklists, timeout procedures, and equipment verification protocols to minimize the risk of complications. Postoperative care coordination involves systematic monitoring for facial nerve function, wound healing, and early complication recognition through experienced nursing assessment and established communication pathways between team members.

Long-term surveillance requires coordinated follow-up scheduling, standardized examination protocols, and clear communication channels to identify and address concerning findings. The interprofessional team should implement quality improvement initiatives, including outcome measurement, complication tracking, and continuous education regarding evidence-based practices. Multiple team members should reinforce patient education and counseling to ensure a thorough understanding of the importance of long-term follow-up, given the potential for recurrence and risk of malignant transformation. Effective care coordination, standardized protocols, and clear communication among all team members ultimately lead to superior patient outcomes, reduced complications, and improved quality of life for patients with pleomorphic adenoma.

Review Questions

• Access free multiple choice questions on this topic.
• Click here for a simplified version.
• Comment on this article.

References

1.

Rourk KS, Daher GS, Schwartz JR, Ali HM, Shurtz AK, Tasche KK, Price DL, Van Abel KM, Yin LX, Moore EJ. Tracking Pleomorphic Adenoma Incidence Trends Over 47 Years: A Population-Based Study. Otolaryngol Head Neck Surg. 2025 Sep;173(3):651-659. [PubMed: 40323181]

2.

Zhan KY, Khaja SF, Flack AB, Day TA. Benign Parotid Tumors. Otolaryngol Clin North Am. 2016 Apr;49(2):327-42. [PubMed: 27040584]

3.

Valstar MH, Mast H, Ten Hove I, Moonen LR, Balm AJ, Smeele LE, Koljenović S, Dinjens WN, van Velthuysen MF. Malignant transformation of salivary gland pleomorphic adenoma: proof of principle. J Pathol Clin Res. 2021 Sep;7(5):432-437. [PMC free article: PMC8363925] [PubMed: 34390320]

4.

Martinelli M, Martini F, Rinaldi E, Caramanico L, Magri E, Grandi E, Carinci F, Pastore A, Tognon M. Simian virus 40 sequences and expression of the viral large T antigen oncoprotein in human pleomorphic adenomas of parotid glands. Am J Pathol. 2002 Oct;161(4):1127-33. [PMC free article: PMC1867276] [PubMed: 12368186]

5.

Toper MH, Sarioglu S. Molecular Pathology of Salivary Gland Neoplasms: Diagnostic, Prognostic, and Predictive Perspective. Adv Anat Pathol. 2021 Mar 01;28(2):81-93. [PubMed: 33405400]

6.

Agaimy A, Ihrler S, Baněčková M, Costés Martineau V, Mantsopoulos K, Hartmann A, Iro H, Stoehr R, Skálová A. HMGA2-WIF1 Rearrangements Characterize a Distinctive Subset of Salivary Pleomorphic Adenomas With Prominent Trabecular (Canalicular Adenoma-like) Morphology. Am J Surg Pathol. 2022 Feb 01;46(2):190-199. [PubMed: 34324456]

7.

Spiro RH. Salivary neoplasms: overview of a 35-year experience with 2,807 patients. Head Neck Surg. 1986 Jan-Feb;8(3):177-84. [PubMed: 3744850]

8.

Mantsopoulos K, Iro AK, Sievert M, Müller SK, Agaimy A, Schapher M, Koch M, Iro H. Is extracapsular dissection for pleomorphic adenoma rather a euphemism for enucleation that jeopardises the intactness of the capsule? Br J Oral Maxillofac Surg. 2021 Dec;59(10):1204-1208. [PubMed: 34274171]

9.

Triantafyllou A, Thompson LD, Devaney KO, Bell D, Hunt JL, Rinaldo A, Vander Poorten V, Ferlito A. Functional Histology of Salivary Gland Pleomorphic Adenoma: An Appraisal. Head Neck Pathol. 2015 Sep;9(3):387-404. [PMC free article: PMC4542802] [PubMed: 25380577]

10.

Rai S, Sodhi SP, Sandhu SV. Pleomorphic adenoma of submandibular gland: An uncommon occurrence. Natl J Maxillofac Surg. 2011 Jan;2(1):66-8. [PMC free article: PMC3304236] [PubMed: 22442613]

11.

Choi N, Kang YJ, Cho J, Oh D, Jeong J, Jeong HS. Topography and probability diagram of cervical and intra-parotid lymph node metastasis in parotid gland cancer. Clin Exp Metastasis. 2024 Feb;41(1):33-43. [PubMed: 38079016]

12.

Harb JL, Zaro C, Nassif SJ, Dhingra JK. Point-of-care ultrasound scan as the primary modality for evaluating parotid tumors. Laryngoscope Investig Otolaryngol. 2022 Oct;7(5):1402-1406. [PMC free article: PMC9575084] [PubMed: 36258876]

13.

Kato H, Kawaguchi M, Ando T, Mizuta K, Aoki M, Matsuo M. Pleomorphic adenoma of salivary glands: common and uncommon CT and MR imaging features. Jpn J Radiol. 2018 Aug;36(8):463-471. [PubMed: 29845358]

14.

Koyama M, Terauchi T, Koizumi M, Tanaka H, Sato Y. Metastasizing pleomorphic adenoma in the multiple organs: A case report on FDG-PET/CT imaging. Medicine (Baltimore). 2018 Jun;97(23):e11077. [PMC free article: PMC5999481] [PubMed: 29879077]

15.

Shalley S, Chand N, Aggarwal A, Garg LN, Yadav V, Yadav A. Diagnostic Accuracy of Fine Needle Aspiration Cytology in Lesions of Oral Cavity and Salivary Glands: A Clinico-Pathological Study. Open Dent J. 2018;12:782-790. [PMC free article: PMC6182874] [PubMed: 30369988]

16.

Zbären P, Vander Poorten V, Witt RL, Woolgar JA, Shaha AR, Triantafyllou A, Takes RP, Rinaldo A, Ferlito A. Pleomorphic adenoma of the parotid: formal parotidectomy or limited surgery? Am J Surg. 2013 Jan;205(1):109-18. [PubMed: 23062782]

17.

Mendenhall WM, Mendenhall CM, Werning JW, Malyapa RS, Mendenhall NP. Salivary gland pleomorphic adenoma. Am J Clin Oncol. 2008 Feb;31(1):95-9. [PubMed: 18376235]

18.

Leverstein H, van der Wal JE, Tiwari RM, van der Waal I, Snow GB. Surgical management of 246 previously untreated pleomorphic adenomas of the parotid gland. Br J Surg. 1997 Mar;84(3):399-403. [PubMed: 9117322]

19.

O'Brien CJ. Current management of benign parotid tumors--the role of limited superficial parotidectomy. Head Neck. 2003 Nov;25(11):946-52. [PubMed: 14603455]

20.

Kaszuba SM, Zafereo ME, Rosenthal DI, El-Naggar AK, Weber RS. Effect of initial treatment on disease outcome for patients with submandibular gland carcinoma. Arch Otolaryngol Head Neck Surg. 2007 Jun;133(6):546-50. [PubMed: 17576904]

21.

Usman S, Ahmed S, Iqbal S, Aslam A. Pleomorphic Adenoma of Minor Salivary Gland. J Coll Physicians Surg Pak. 2022 Apr;32(4):S70-S72. [PubMed: 35633018]

22.

Jardel P, Fakhry N, Makeieff M, Ferrie JC, Milin S, Righini C, Lacout A, Costes V, Malard O, Marcy PY, Guevara N, Odin G, Bensadoun RJ, Thariat J. [Radiation therapy for pleomorphic adenoma of the parotid]. Cancer Radiother. 2014 Jan;18(1):68-76. [PubMed: 24387927]

23.

Nicholas SE, Fu W, Liang AL, DeLuna R, Vujaskovic L, Bishop J, Page BR, Quon H, Gourin C, Fakhry C, Eisele D, Kiess AP. Radiation Therapy After Surgical Resection Improves Outcomes for Patients With Recurrent Pleomorphic Adenoma. Adv Radiat Oncol. 2021 May-Jun;6(3):100674. [PMC free article: PMC8233456] [PubMed: 34195493]

24.

Kalwaniya DS, Meena R, Kumar D, Tolat A, Arya SV. A Review of the Current Literature on Pleomorphic Adenoma. Cureus. 2023 Jul;15(7):e42311. [PMC free article: PMC10442517] [PubMed: 37614271]

25.

Hocwald E, Korkmaz H, Yoo GH, Adsay V, Shibuya TY, Abrams J, Jacobs JR. Prognostic factors in major salivary gland cancer. Laryngoscope. 2001 Aug;111(8):1434-9. [PubMed: 11568581]

26.

Mra Z, Komisar A, Blaugrund SM. Functional facial nerve weakness after surgery for benign parotid tumors: a multivariate statistical analysis. Head Neck. 1993 Mar-Apr;15(2):147-52. [PubMed: 8382671]

27.

Infante-Cossio P, Gonzalez-Cardero E, Garcia-Perla-Garcia A, Montes-Latorre E, Gutierrez-Perez JL, Prats-Golczer VE. Complications after superficial parotidectomy for pleomorphic adenoma. Med Oral Patol Oral Cir Bucal. 2018 Jul 01;23(4):e485-e492. [PMC free article: PMC6051677] [PubMed: 29924764]

Disclosure: Gopal Menon declares no relevant financial relationships with ineligible companies.

Disclosure: Ryan Winters declares no relevant financial relationships with ineligible companies.