Case Report
Giant Parotid Pleomorphic Adenoma with Atypical Histological Presentation and Long-Term Recurrence-Free Follow-Up after Surgery: A Case Report and Review of the Literature
Mohammed AlKindi ,1Sundar Ramalingam ,1Lujain Abdulmajeed Hakeem ,1 and Manal A. AlSheddi 2
1Department of Oral and Maxillofacial Surgery, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
2Department of Basic Sciences, College of Dentistry, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia Correspondence should be addressed to Sundar Ramalingam; sundar.ksu@gmail.com
Received 5 July 2020; Revised 14 August 2020; Accepted 21 August 2020; Published 1 September 2020 Academic Editor: Pravinkumar G. Patil
Copyright © 2020 Mohammed AlKindi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Salivary gland tumors (SGT) comprise 3% of all head and neck tumors, are mostly benign, and arise frequently in the parotid gland.
Pleomorphic adenoma (PA) is the commonest SGT, representing 60-70% of all benign parotid tumors. Clinically, parotid PA presents as irregular, lobulated, asymptomatic, slow-growing preauricular mass, involving both superficial and deep lobes, and could grow to gigantic proportions. Histologically, PA has epithelial and mesenchymal elements in chondromyxoid matrix and is managed surgically. Based on a review of 43 cases reported in English literature since 1995, giant parotid PA is reported as large as 35 cm (diameter) and 7.3 kg (resected weight). Although rare, 10 cases of malignant transformation were reported in the review. Surgical management included extracapsular dissection (ECD), superficial parotidectomy, and total parotidectomy for benign tumors, and adjuvant radiation or chemotherapy for malignant tumors. We further present the case of a 36-year-old healthy male with slow-growing and asymptomatic giant parotid PA, of 4-year duration. The patient presented with firm, lobulated preauricular swelling, provisionally diagnosed as PA based on radiographic and cytologicalfindings. The tumor was resected through ECD, and the patient had uneventful postoperative recovery and a 7-year recurrence-free follow-up period.
Histological examination revealed epimyoepithelial proliferation punctuated by chondromyxoid areas, with extensive squamous metaplasia and keratin cysts. To the best of knowledge from indexed literature, giant parotid PA is rarely reported in Saudi Arabia. In addition to its rarity, this case is reported for its benign nature despite atypical histological presentation, successful surgical management without complications, and long-term recurrence-free follow-up. Based on this report, clinicians must be aware of atypical histological presentations associated with PA and plan suitable surgical management and follow-up to avoid morbidity. Nevertheless, attempts must be made to diagnose and manage these lesions at an early stage and before they reach gigantic proportions.
1. Introduction
Neoplastic lesions of the salivary glands are uncommon and comprise less than 3% of all reported head and neck tumors [1, 2]. Nearly 80% of the reported salivary gland tumors (SGT) are benign and occur predominantly in major salivary glands, with the parotid gland being the commonest site (70– 80%) [2, 3]. Often presenting as slow-growing, painless masses, tumors involving major salivary glands are rarely
aggressive or malignant (<10%). On the contrary, tumors of minor salivary glands while occurring rarely have a prepon- derance to be malignant (80–90%) [2, 3]. Pleomorphic ade- noma (PA) is the commonest SGT, accounting for almost 60–80% of all benign SGT and 60–70% of all parotid gland tumors [1, 3]. Clinically, PA presents as an irregular, rubbery, lobulated, slow-growing mass without any associated pain or discomfort. The presenting complaint is typically related to unpleasant or unesthetic facial appearance, which when
https://doi.org/10.1155/2020/8828775
disregarded can lead to patients reporting with huge lesions [4]. Reports in the literature suggest resected dimensions of PA to be frequently in the range of 2 cm to 6 cm and rarely reaching even up to 25–35 cm [4, 5].
As the name suggests, PA is histologically categorized as a benign mixed (pleomorphic) tumor of ductal and myoe- pithelial cell origin. Owing to the pluripotential nature of myoepithelial cells, the tumor is composed of epithelial and fibrous, myxoid, and cartilaginous mesenchymal elements surrounded by a pseudocapsule, with occasional squamous metaplasia [3, 4, 6]. While the diagnosis of PA is based pri- marily on clinical and histologicalfindings, the mainstay of management is by surgical excision [1, 4]. Depending upon their size and depth of involvement, parotid PA is surgically managed either by superficial parotidectomy (SP), extracap- sular dissection (ECD), or total parotidectomy (TP). All of the above procedures carry the risk of postoperative facial nerve paralysis and Frey’s syndrome [1, 7]. Recurrence is usually associated with inadequate clearance and incomplete removal of pseudocapsule, and malignant transformation has been reported with large, long-standing PA [4, 7].
Although uncommon, giant pleomorphic adenomas of the parotid gland have been reported. An electronic search of the English-language articles through the Medline, Scopus, and Google Scholar databases revealed 43 reports of giant parotid PA since 1995 [4, 8–32], with sizes ranging up to 28-33 cm [15, 18, 27] and tumor mass ranging up to 6.85– 7.3 kg [10, 27]. Major reasons for patients reporting with large PA are lack of resources, inaccessibility to medical facil- ities, fear of surgical procedure, and poor awareness, com- pounded by an asymptomatic and slow-growing lesion [4].
The aim of this paper is to add to the existing scientific liter- ature, a case of giant parotid PA treated surgically by ECD, followed by uneventful postoperative recovery and a 7-year recurrence-free follow-up. This paper also attempts to high- light the benign nature of parotid PA, despite the atypical histological presentation, which could be associated with it.
2. Case Report
A 36-year-old healthy male patient reported to the oral and maxillofacial surgery outpatient clinic at the College of Dentistry and Dental University Hospital, King Saud University, in October 2012. The patient sought medical attention for a slow-growing, painless swelling in the right preauricular region. History revealed that the patient noticed the swelling almost 4 years ago, and since then, it had gradually increased in size with no obvious symp- toms or changes to the overlying skin. Upon interviewing, the patient reported no relevant medical or surgical history and mentioned fear of surgery and absence of discomfort as reasons for delaying medical consultation, in spite of an unesthetic facial appearance.
Clinical examination revealed afirm, nontender, nodular, and mobile swelling with apparently normal overlying skin.
The swelling extended superoinferiorly from the level of the external ear to the lower border of the mandible and antero- posteriorly from the angle of the mouth to the posterior bor- der of the mandible. There was no lymph node involvement
or facial nerve deficit (Figure 1). Preoperative computed tomography (CT), magnetic resonance imaging (MRI), and fine-needle aspiration cytology (FNAC) were ordered. CT with contrast revealed a well-defined mass lesion in the superficial lobe of the right parotid gland, without any under- lying bony erosion and normal-appearing pharynx, larynx, and parapharyngeal spaces. While confirming the CT find- ings, head and neck MRI further demonstrated a well-demar- cated, heterogeneous, mass lesion measuring10 × 7 × 8 cm in maximum dimension (Figure 2). FNAC showed numerous scattered groups and clusters of plasmacytoid myoepithelial cells, associated with a chondromyxoid matrix. A provisional diagnosis of PA with no malignant tendency was arrived at based on CT, MRI, and FNACfindings.
Surgical removal of the right parotid SGT under general anesthesia was planned and explained to the patient. Follow- ing informed consent, the lesion was excised completely through ECD, with preservation of all branches of the facial nerve. The right parotid gland was approached using a cervi- cally extended preauricular skin incision. A clearly discern- ible plane of dissection around the tumor was used for dissecting the tumor mass, without any iatrogenic damage to the facial nerve branches. Owing to the long-standing nature, multiple small feeder vessels had to be ligated circum- ferentially around the tumor to achieve hemostasis. The intraoperative period was unremarkable, and the patient did not require any blood transfusions (Figure 3). The resected mass was bilobed and ovoid in shape with a final dimension of7 × 13 × 7 cm and weighing 1.2 kg.
Histopathological examination of the excised specimen gave a gross appearance of a partially encapsulated mass con- taining myoepithelial and ductal proliferation. There was marked stromal hyalinization, squamous metaplasia, and keratinization. Some epithelial islands exhibited papillary configuration, along with large cysts and inflammation.
Chondromyxoid changes andfibrosis were evident through- out the tumor. Certain foci of tumor islands were seen approaching and breaking through it. Hematoxylin and eosin (H&E) stained sections revealed a partially encapsulated tumor with variable histopathological features and focal effacement of the fibrous capsule. The tumor typically showed epithelial/myoepithelial proliferation punctuated by chondromyxoid areas. Aggregates of plasmacytoid myoe- pithelial cells as well as ducal differentiation surrounded by clear myoepithelial cells were evident. Based on the above findings, a final diagnosis of benign PA was reached. While the tumor sections showed no evidence of malignant change, there was extensive squamous metaplasia and keratin cyst formation, which were atypical for PA (Figure 4). The patient was therefore advised close follow-up, once every month for thefirst year postoperatively and subsequently once in six months.
At 6 weeks postsurgery, the patient had unremarkable wound healing without any neurological deficit of the facial nerve (Figure 5). As of December 2019, the patient had a recurrence-free follow-up period of 7 years and presented with normal activity of muscles of facial expression, indicat- ing the absence of any long-term facial nerve weakness (Figure 6).
3. Discussion
The parotid gland is the largest salivary gland with an average weight ranging from 0.015 to 0.021 kg and measuring approx- imately 5:8 × 3:4 cm in the craniocaudal and ventrodorsal dimensions, respectively. Being the first salivary gland to
develop in utero, during the 6thgestational week, it is anatom- ically located bilaterally between the mastoid process of temporal bone and ramus of the mandible. The terminal branches of the facial nerve are an important anatomic land- mark which divide the parotid gland into its superficial and deep lobes [33]. Although SGT are uncommon, they are
(a) (b)
Figure 1: Preoperative clinical photograph of the right preauricular swelling. (a) Right lateral facial view shows the swelling extending superoinferiorly from a point anterior to the helix of the external ear until the lower border of the mandible; anteroposteriorly, the swelling is seen extending from the angle of the mouth to the posterior border of the mandible; the ear lobe is deflected outward and elevated, and the skin overlying the swelling appears free of any ulceration, puckering, or discharge. (b) Frontal facial view shows the swelling causing facial asymmetry and obliterating the view of most of the right external ear; there is no clinical evidence of facial nerve weakness or deficit.
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Figure 2: Preoperative radiographic examination of the right preauricular swelling. (a) Contrast-enhanced computed tomography axial section at the level of mandibular teeth shows a well-defined mass lesion in the superficial lobe of the right parotid gland, without any underlying bony erosion and normal-appearing pharynx, larynx, and parapharyngeal spaces. (b) Magnetic resonance imaging coronal section along the posterior border of the mandible shows a large, heterogeneous, well-demarcated solid mass lesion within the right parotid superficial lobe and measuring 10 × 7 × 8 cm at maximum dimensions.
predominantly benign and are reported frequently in the parotid gland [2]. The present report details a case of giant PA in the right parotid gland, along with its surgical manage- ment, histological presentation, and long-term recurrence-free follow-up.
Pleomorphic adenoma is the commonest mixed SGT arising in the parotid gland, and several cases have been reported in the literature. Although there are no specific physical criteria outlined in the literature to classify giant parotid PA, the earliest recorded case report dates back to 1863 [27]. In this report, Spence reported a mixed tumor involving lateral face and neck and a resected mass weighing greater than 1 kg [27]. Similarly, Short and Pullar (1956) reviewed and reported a case of giant parotid PA weighing about 2.3 kg [27]. In a report reviewing 31 cases of giant parotid PA over a period of 140 years by Schultz-Coulon, the resected tumor weights ranged from 1.0 to 26.50 kg, with a greater female predilection (64.5%) and only 3 cases of malignant transformation [15]. Based on a review of the 10
largest parotid PA published between 1863 and 1994, Buent- ing et al. reported resected tumors ranging in weight from 2.83 to 26.50 kg, in patients with age ranging from 25 to 85 years and 90% female predilection [10].
A literature search was conducted to review giant parotid PA cases reported in Medline, Scopus, and Google Scholar databases. The search strategy involved a combination of search keywords including“GIANT”, “PAROTID GLAND”, and “PLEOMORPHIC ADENOMA”, based on which 288 articles were identified from the three databases (Med- line—66; Scopus—63; Google Scholar—159). Reviewing their abstracts, articles published in English only were selected based on them reporting a case or series of cases of giant parotid PA, including clinical, radiographic, histologi- cal, and surgical outcomes. Twenty-six articles published in English language were identified [4, 8–32] since 1995, and they reported 43 cases of PA in total. While most of the arti- cles selected for review were single case reports, three articles were case series reporting about two cases [16], three cases
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Figure 3: Intraoperative photograph showing (a) the surgical plane for extracapsular dissection of the right parotid tumor and (b) the excised tumor specimen.
500 𝜇m
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200 𝜇m
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Figure 4: Histological examination of the excised tumor specimen showing (a) a partially encapsulated mass lesion containing myoepithelial and ductal proliferation, with stromal hyalinization, squamous metaplasia, and keratinization; epithelial islands exhibiting papillary configuration, large cysts surrounded by inflammation, focal areas of chondromyxoid changes and fibrosis, and tumor islands approaching and penetrating the capsule are evident (HE original magnification ×4); (b) extensive squamous metaplasia and keratin cyst formation are conspicuous at higher magnification (HE original magnification ×10).
[17], and 15 cases [32], respectively. The largest case series in the present review, comprising 15 PA patients, was reported by Pareek et al. [32].
Although majority of the reported cases were in patients aged 45 years or older (n = 30, 69.8%), the age at clinical pre- sentation and surgery ranged from 21 to 92 years. The asymptomatic, slow-growing nature of pleomorphic ade- noma was evidenced by the fact that the duration from the first observation of lesion to reporting for treatment varied from 5 to 35 years. Demographically, there were more females (n = 25, 58.1%) than males, and all reported cases were unilateral, with the right side (n = 23, 53.5%) affected more than the left. In terms of clinical dimension, the tumors ranged from 3 to 5 cm in diameter [16, 17], until35 × 28 cm [27], in two perpendicular planes. The clinical dimensions corroborated with the resected tumor weight, wherein the smallest tumor weighed 0.12 kg [16] and the largest weighed 7.3 kg [27]. Predominant clinical presentation of the tumors was that of a large, lobulated, and pedunculated mass with apparently normal overlying skin. Ulceration of the skin was reported in eight patients, out of whichfive were report- edly associated with malignant change [15, 23, 24, 30, 32], and the remaining three were due to injury [18, 29, 32]. Ana- tomically, the tumor more commonly involved the superfi- cial lobe of the parotid gland (n = 29, 70.7%) giving rise to the clinical presentation of a large preauricular mass. Never- theless, when the deep lobe of parotid and parapharyngeal spaces were involved by the tumor, patients presented with an intraoral swelling leading to soft palate displacement, dif- ficulty in swallowing and breathing, and obstructive sleep apnea [11, 13, 16, 17, 22, 25]. While diagnosis was primarily based on clinical and radiographic (USG, CT, and MRI)find- ings, preoperative diagnosis was established through FNAC
in most cases. The clinical, radiographic, surgical, and histo- logicalfindings in the reviewed case reports are detailed in Table 1.
Preoperative diagnosis of PA is routinely based on clini- cal findings, supplemented by radiological investigations such as CT, MRI, and USG [2]. The role of FNAC in arriving at a provisional diagnosis has been debated and considered nonrepresentative due to varying histological patterns at dif- ferent sites within the same tumor [34]. In terms of histo- pathological diagnosis, the characteristic feature of PA is its histological diversity and differing arrangements of epithelial and mesenchymal tissue elements. Das and Anim [34], based on a study comparing FNAC and histological sections in PA, reported consistent findings of epithelial cells in a myxoid stroma through cytological and histological examination.
Nevertheless, they reported better characterization of onco- cytic changes such as acini, giant cell and mucus globule for- mation, and squamous and chondroid metaplasia in histological sections [34]. Preoperative diagnosis of PA in the present case was based on a combination of clinical examination, radiographic investigations, and FNAC. Our radiographicfinding (CT and MRI) of well-demarcated, lob- ulated, and heterogeneous mass lesion involving the parotid gland and FNACfinding of plasmacytoid epithelial cells in a chondromyxoid matrix were in coherence with the major- ity of cases reported in the review (Table 1). Additionally, necrotic changes [10, 24, 30] and calcifications [4, 30], within the tumor, have also been reported in the literature, based on CT and in association with malignant change [24, 30]. The combination of CT and MRI enables optimum preoperative diagnosis of pleomorphic adenomas and precise planning of the surgical approach for tumor resection [11]. In addition to volumetric information, CT with contrast provides
(a) (b)
Figure 5: Postoperative clinical photograph taken 6 weeks postsurgery. (a) Lateral facial view shows healing surgical incision without any obvious postoperative sequelae. (b) Symmetric facial appearance observed in the frontal facial view, with no clinical weakness of muscles of facial expression.
knowledge about vascularity of the tumor and MRI shows the relationship of the tumor to surrounding vital structures in the head and neck regions [11].
The treatment of PA irrespective of their size, severity, or malignant potential is only by surgery. Based on our litera-
ture review, giant PA involving the superficial lobe of parotid was managed either by SP or ECD [4, 10, 24, 26–29, 31, 32].
On the contrary, TP was reportedly done for tumors exhibit- ing malignant characteristics [8, 12, 15, 17, 19, 20, 23, 30] and those involving both the deep and superficial lobes [9, 13, 14,
(a) (b)
(c) (d)
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Figure 6: Postoperative clinical photograph taken 7 years postsurgery with facial gestures eliciting unrestrained action of different muscles of facial expression. (a) Unremarkable healing of the surgical wound without any scarring and the patient is seen smiling. (b) Frontal facial view showing symmetric appearance and the patient is seen puffing the cheeks. (c, d) Bilateral symmetric eyelid closure and opening. (e) The patient is seen grinning broadly.
Table1:Reviewofgiantparotidpleomorphicadenomacasereportsandtheirdemographic,clinical,radiographic,surgical,andhistologicalfindings. Author(year)PatientdemographicsPreoperativeevaluationSurgicalinterventionPostoperativeperiod Age(in years)/genderDuration oflesionAffected sideClinical dimensionClinical presentationInvestigationsProcedureResected dimensionReasonfor surgeryHistologicalfindingsPostoperative courseFollow-up Alvarez-Cañas andRodilla (1996)[8]86/F15yearsLeft Largepainless preauricularmass whichenlarged suddenlyoverthe past1yearand associatedwith facialnervedeficit
Onlyclinical examinationTotalparotidectomy9:5×8×7cm Suddenincrease insizewith facialnerve deficit Mixedmalignant transformationof PAwithsalivary ductalcarcinoma andhigh-grade fibrosarcomaelements
Patient developedlocal recurrenceof tumoranddied 6monthsafter surgery Lomeo(1996) [9]74/F35yearsLeftLargepreauricular massOnlyclinical examinationTotalparotidectomy
Patientwas convincedfor surgeryby grandchildren
Pleomorphic adenoma Buentingetal. (1998)[10]85/F20yearsRight
Large,multinodular preauricularmass withevidenceof infection.Themass wastenselycystic andhadprominent veinsnearthebase CTshoweda parotidmass14cm acrosswith extensivenecrotic fociandnumerous feedingvessels, whichwerenot amenableto embolization
Extracapsular dissectionofthe tumormass 26cmdiameter (6.85kg) Inadvertent injurytothe baseofthemass resultingin bleedingand infection
Pleomorphicadenoma withextensive necrosisand cartilaginous metaplasia
1-year recurrence-free follow-up Rodriguez- Ciuranaetal. (2000)[11]48/F30yearsRight
Largemassinthe submandibularand laterocervical regions,extending intraorallyfrom soft-palatetofloor ofmouth
MRIshowedamass involvingthedeep lobeoftheparotid gland,extending into parapharyngeal, prestyloid,and submandibular spaces,displacing externaland internalcarotid arteriesand thinningtheramus ofmandible. Measuring6×5×4 cm.FNACwas indicativeofPA Deeplobe parotidectomy throughcervical transparotid approach
Pleomorphic adenoma
Transientfacial nerveweakness for4weeks Manuel(2002) [12]68/FLeft
Recurrentparotid masswhichwas incompletely excisedearlierand diagnosedasmixed malignanttumor Total parotidectomy,with removaloffacial nervebranchesdue totumorinfiltration andmodifiedneck dissection
Recurrentlesion inthepreviously excisedtumor site Carcinosarcomaarising fromPA,withresidual PA,epimyoepithelial carcinoma,and pleomorphicsarcoma. Multiplemetastatic cervicallymphnodes Patientwas operatedfor metastatic anteriorchest wallmass,7 months postsurgeryand hadan18- monthdisease- freefollow-up
Table1:Continued. Author(year)PatientdemographicsPreoperativeevaluationSurgicalinterventionPostoperativeperiod Age(in years)/genderDuration oflesionAffected sideClinical dimensionClinical presentationInvestigationsProcedureResected dimensionReasonfor surgeryHistologicalfindingsPostoperative courseFollow-up Panoussopoulos etal.(2002)[13]63/M30yearsLeft13×12cm
Large,lobulated massinthe submandibular, preauricular,and laterocervical regions,extending intraorallytothe lateralpharyngeal wallatthelevel oftongue MRIshowedawell- definedmass involvingboth superficialanddeep lobesoftheparotid gland,and extendingintothe parapharyngeal space,displacing tissuesdeepto thetonsil
Totalparotidectomy throughcervical transparotid approach
Pleomorphic adenoma deSilvaetal. (2004)[14]76/M>30yearsLeft20×30cm
Large,oval preauricular swelling,firmin consistency, withvenous engorgementon overlyingskin andmovable FNACwas indicativeofPA Totalparotidectomy withpreservationof facialnerve
20×14×12cm (3.5kg)Pleomorphic adenoma Facialnerve deficitobserved 1week postoperatively andrecovered 90%by 1month
1-year recurrence-free follow-upand complete recoveryof facialnerve function Hondaetal. (2005)[15]72/F20yearsLeft
Large,pedunculated preauricularmass extendinguptothe submandibular region,witha historyofrapid growthinpreceding 3monthsand2 areasofulceration withyellowish,foul- smellingdischarge inthelowerpartof themass.An associatedanterior chestwallmass measuring10×8 cmwasclinically identified CTshowedamass withmultiple encapsulated nodulesinvolving theentireparotid gland,having severalfeeder vesselsandsupplied predominantlyby thetransversefacial artery.Coincidental findingofabnormal skullbaselesion measuring4cmin diameter.Chest radiographrevealed multiplemetastatic nodules,measuring around1cm,in bothlungs
Totalparotidectomy +simultaneous resectionofanterior chestwallmass 33×18×17:5cm exophytictumor (6.051kg) Suddenincrease insizewith ulcerationand discharge Pleomorphicadenoma withfocalareasof malignant adenocarcinomacells withhyperchromatic nucleiandincreased mitoticfigures.Similar histologicalfindings observedintheresected anteriorchestwallmass
Patientdied6 months postsurgery, dueto metastaticlung disease
Table1:Continued. Author(year)PatientdemographicsPreoperativeevaluationSurgicalinterventionPostoperativeperiod Age(in years)/genderDuration oflesionAffected sideClinical dimensionClinical presentationInvestigationsProcedureResected dimensionReasonfor surgeryHistologicalfindingsPostoperative courseFollow-up Ruiz-Lazaetal. (2006)[16]54/M5yearsLeft3cm
Solidmassin preauricularand mandibularangle regions
MRIshoweda multilobulatedmass measuring8cmin diameterand extendingfrom deeplobeofthe parotidglandinto parapharyngeal space,displacingthe pharyngealairway mediallyandthe jugularandcarotid vesselsposteriorly. FNACwas indicative ofPA Totalparotidectomy throughcervical transparotid approachand facialnerve preservation
Pleomorphic adenoma Postoperative facialnerve deficitwhich recovered completelyin 6months
3-year recurrence-free follow-up Ruiz-Lazaetal. (2006)[16]21/MRight
Intraoralmass occupyingtheentire softpalatewithno otherassociated symptoms MRIshowedawell- definedmasslesion measuring6×5×4 cminthe parapharyngeal spaceandwith apparentcontinuity tothedeeplobeof theparotidgland. FNACwas indicativeofPA
Surgicalexcisionof tumormassonly, throughintraoral approachand “Double-Y”incision insoftpalate 11×10cm (0.12kg)Pleomorphic adenoma
3-year recurrence-free follow-up Sergietal. (2008)[17]36/M1yearLeft5cmSolidpreauricular mass
USGshowedtwo hypoechogenic, lobulatedmasses measuring2:5×1:9 ×1:6cminthedeep lobeoftheparotid glandand4:4×5:1 ×4:6cmposterior tomandibular ramus.MRI revealedexpansive massmeasuring about5cminthe deeplobeofthe parotidgland, extendingfrom mandibularangleto lateralpharyngeal wallmedially Usingcervical transparotid approach, superficialanddeep lobeparotidectomy performed separatelyto preservefacial nervebranches
Pleomorphic adenoma Transient neurological deficitof marginal mandibular branchof facialnerve
Table1:Continued. Author(year)PatientdemographicsPreoperativeevaluationSurgicalinterventionPostoperativeperiod Age(in years)/genderDuration oflesionAffected sideClinical dimensionClinical presentationInvestigationsProcedureResected dimensionReasonfor surgeryHistologicalfindingsPostoperative courseFollow-up Sergietal. (2008)[17]42/MRight3cmSolidpreauricular mass
MRIshowedamass inthedeeplobeof theparotidgland, extendinginto parapharyngeal spaceanddisplacing thepharyngeal musclesmedially. FNACwas indicativeofPA Usingcervical transparotid approach, superficialanddeep lobeparotidectomy performed separatelyto preservefacialnerve branches
Increasedinsize over2monthsPleomorphic adenoma Sergietal. (2008)[17]38/FLeft
Noextraoral swelling.Intraoral masslateraltothe softpalateand displacingitacross themidline
MRIshowed inhomogeneous, expansivemass arisingfromthe deeplobeofthe parotidglandand measuring5:5×5:5 cminthelateral pharyngealspace. Themasswasseen displacingthe pterygoidand pharyngealmuscles medially.FNACwas indicativeofPA Separatesuperficial anddeeplobe parotidectomy through transcervical, mandibularsplit approachto preservefacialnerve branches
Painwhile swallowingand sensationof foreignbodyin thethroatsince 5months Pleomorphicadenoma withanucleusof carcinomaex-PA
Postoperative radiotherapy Takahamaetal. (2008)[18]78/M>30yearsRight30cm
Large,multinodular preauricularmass extendingtothe submandibular regionandcrossing themidline.Focal areasofulceration inthelowerpartof themass
Onlyclinical examinationTotalparotidectomy28×20×16cm (4.0kg)Pleomorphic adenoma Bhutta(2009) [19]63/FLeftSlow-growingmass intheleftsuperficial parotid Onlyclinical examination Excisiondonein 1993,followedby multiplerecurrences managedsurgically throughexcision from1995-2006 Earlylesionwas suggestiveofPA. Recurrentlesions resembledPAwith highmitoticrate andnomalignancy 45Gyexternal beamradiation therapy(in25 fractions)given in2000to prevent recurrence In2006,CT showedaright kidneymass, diagnosedas metastasizing PAbyhistology (typicalfeatures ofPAwith positiveKi67 staining)
Table1:Continued. Author(year)PatientdemographicsPreoperativeevaluationSurgicalinterventionPostoperativeperiod Age(in years)/genderDuration oflesionAffected sideClinical dimensionClinical presentationInvestigationsProcedureResected dimensionReasonfor surgeryHistologicalfindingsPostoperative courseFollow-up Karpowiczetal. (2010)[20]45/MRight
Subcutaneous parotidmasswith ipsilateralcervical lymphadenopathy involvingmultiple nodes.Associated withseverepainand rapidincreasein size.Clinically stagedasstageIva malignantdisease Onlyclinical examination
Totalparotidectomy withcomprehensive neckdissection Nonencapsulated tumormeasuring about3.5cm Severepainand rapidincrease insize
Malignantepithelial cellsina chondromyxoidstroma indicativeofcarcinoma ex-PA.Malignantfoci includedhigh-grade squamouscell carcinomaand adenocarcinoma.One ofthecervicallymph nodesshowedevidence ofmetastaticcarcinoma. Immunohistochemistry identifiedamelanoma component Twomonths postsurgery,the patientreported severepelvic pain,diagnosed asmetastatic bonedisease throughMRI
Patientdied3 months postsurgerydue tometastatic disease Cetinetal. (2012)[21]55/F20yearsLeft15×15×20cm
Largepreauricular massextendingto cervicalregions, withoverlyingskin atrophicand vascular USGshoweda lobulatedmassin theparotidgland withboth homogeneousand heterogeneous echotextures
TotalparotidectomyPleomorphic adenoma Morariuetal. (2012)[22]42/MRight
Largemassarising fromthelateral pharyngealwall, displacingthesoft palateanduvula, andnarrowingthe pharyngealairway. Associated symptomsof painfulswallowing, heavysnoring,and sleepapneaforpast 1year MRIshoweda circumscribedmass lesion7×6×4cm extendingfromthe deeplobeofthe parotidglandinto theparapharyngeal spacewithfluid spacesand septation.CT angiogramwhile showingsplayed internaland externalcarotid arteries,ruledout anyabnormal vascularity. TransoralFNAC wasindicativeofPA
Deeplobe parotidectomy through transparotid approach Pharyngodynia andnocturnal hypoxia symptoms
Pleomorphic adenoma Patientreported relieffrom nocturnal hypoxia, snoring,and sleepapnea symptoms, postoperatively
6-month recurrence-free follow-up
Table1:Continued. Author(year)PatientdemographicsPreoperativeevaluationSurgicalinterventionPostoperativeperiod Age(in years)/genderDuration oflesionAffected sideClinical dimensionClinical presentationInvestigationsProcedureResected dimensionReasonfor surgeryHistologicalfindingsPostoperative courseFollow-up Yoshidaetal. (2013)[23]40/F17yearsLeft
Smallparotid swellingbefore17 years,diagnosedas PAbyFNAC. Surgerydelayedfor 10yearsdueto patient’sfearand thenlosttofollow- up.Swellinggrew rapidlyinpast6 months,causing gaitdisturbanceand skinulcerationwith foul-smelling, bloodydischarge fromthelower partoflesion CTshoweda nodularmass arisingfromthe parotidglandand attachedinits deeperaspecttothe carotidsheath. Evidenceof metastasisinchest radiographowingto bilateralhilar lymphadenopathy andcoin-shaped radiolucencyinthe rightlung.Incision biopsywas indicativeofPA, withclinical suspicionof malignancy
Totalparotidectomy andenbloc resectionofthe tumoralongwith thelowerportionof theauricle 25×28×18cm (4.80kg) Rapidgrowthof tumorinlast6 monthswith cervicaland thoracic scoliosisand gaitdisturbance Nearly80%ofthe resectedtumorsections showedevidenceofPA. Sectionsofthetumor neartheulceratedareas showedundifferentiated malignantcells indicativeof carcinomaex-PA
Postoperative adjuvant chemotherapy formetastasis
6-month follow-upwith nolocal recurrence Pamuketal. (2014)[24]82/F20yearsRight13×13×10cm
Large,multilobular preauricularmass withareasof ulcerationand necrosison overlyingskin
CTshowedagiant, exophyticmassin thesuperficiallobe oftheparotidgland withmultiple necroticspacesand enhanced vascularity. Incisionalbiopsy wasindicativeofa salivarygland neoplasmwithout rulingout malignant transformation Superficial parotidectomywith excisionofoverlying ulceratedskin
14×12×9cm
Pleomorphicadenoma withmultiplefociof neoplasticproliferation, alongwithcellular atypiaandnecrosis. Finaldiagnosis carcinomaex-PA Postoperative radiotherapy 60Gy
Patientdied8 months postsurgery dueto cerebrovascular accident Datarkarand Deshpande (2014)[25]40/FRight
Large,firmintraoral massarisingfrom thelateral pharyngealwall, displacingthesoft palateandcrossing midline.Associated symptomsof difficultyin swallowingand breathing,andsleep apneaforpast6 months CTshowed parapharyngeal spacemass extendingmedially acrossthemidline andlaterally betweenthe posteriorborderof ramusandstyloid process.MRI showedlobulated, homogeneousmass lesionextending
Deeplobe parotidectomy through transcervical, mandibularsplit osteotomyapproach
5:5×6:5×3:5cm
Difficultyin swallowingand breathing,and sleepapnea Pleomorphic adenoma Patientreported relieffromsleep apnea symptoms, postoperatively
Table1:Continued. Author(year)PatientdemographicsPreoperativeevaluationSurgicalinterventionPostoperativeperiod Age(in years)/genderDuration oflesionAffected sideClinical dimensionClinical presentationInvestigationsProcedureResected dimensionReasonfor surgeryHistologicalfindingsPostoperative courseFollow-up fromthedeeplobe oftheparotidgland withhypointense septaeand measuring5:4×6:5 ×3:5cm,and indentingonlateral pharyngealwall.No involvementofskull baseorintracranial extensionwas observed.Transoral FNACwas indicativeofPA Sajidetal. (2015)[26]47/M>7yearsRight26×20cm
Large,nodular preauricularmass extendingupto submandibular regioninferiorly andanteriorlyupto 2cmposteriorto thenasolabialfold MRIshoweda heterogeneous, lobulatedmassin thesuperficiallobe oftheparotidgland, extendingmedially uptosternomastoid andcarotidsheath. FNACwas indicativeofPA
Superficial parotidectomywith excisionof redundantskin
22×24×12cm (1.8kg)Pleomorphic adenoma Tarsitanoetal. (2015)[27]83/M>30yearsLeft35×28cm
Giant, multinodular, pedunculatedmass inthepreauricular region,extending uptothecervical region
MRIshowedagiant, heterogeneousmass arisingfromthe superficiallobeof theparotidgland, withwell- demarcated boundariesand preservationof surroundingtissue planes.CTrevealed primaryblood supplythoughfacial arteryand numeroussmall feedervessels. Incisionalbiopsy confirmedthe diagnosisofPA Extracapsular dissectionofthe tumormass
33×27×16cm (7.3kg) Themass becametoobig andahindrance forthepatientto ambulate
Pleomorphic adenoma 5-year recurrence-free follow-up
