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| {{SI}} | | {{Pleomorphic adenoma}} |
| {{CMG}} {{AE}} {{MV}}
| | '''For patient information, click [[Pleomorphic adenoma (patient information)|here]]''' |
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| {{SK}} Pleomorphic adenoma of the salivary glands; BMT; Benign mixed tumors of the salivary gland
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| ==Overview==
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| '''Pleomorphic adenoma''' (also known as "Benign mixed tumor of the salivary gland") is a benign neoplastic tumor of the [[salivary gland]]s. Pleomorphic adenoma is the most common type of salivary gland tumor and the most common tumor of the [[parotid gland]].<ref name="radiographics">Ewa J. Bialek, Wieslaw Jakubowski, Piotr Zajkowski, Kazimierz T. Szopinski, and Antoni Osmolski. [http://radiographics.rsnajnls.org/cgi/content/abstract/26/3/745 US of the Major Salivary Glands: Anatomy and Spatial Relationships, Pathologic Conditions, and Pitfalls.] RadioGraphics 2006 26: 745-763. </ref>
| | {{CMG}}; {{AE}} {{M.N}} |
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| ==Historical Perspective==
| | {{SK}} |
| *Pleomorphic adenoma was first discovered by Beahrs in in 1957.
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| ==Classification== | | ==[[Pleomorphic adenoma overview|Overview]]== |
| *Pleomorphic adenoma may be classified according to anatomical distribution into 4 groups:
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| :*Parotid gland pleomorphic adenoma
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| ::*Superficial lobe pleomorphic adenoma (most common)
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| :*Submandibular gland pleomorphic adenoma
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| :*Minor salivary gland pleomorphic adenoma
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| :*Sublingual gland pleomorphic adenoma
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| *Pleomorphic adenoma may also be classified
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| Three histological types have been described:
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| :*Mixed (hypocellular)(most common)
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| :*Cellular
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| :*Classic
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| *Other variants of pleomorphic adenoma, include: lacrimal gland pleomorphic adenoma, where they account for approximately 50% of lacrimal gland tumors.
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| ==Pathophysiology== | | ==[[Pleomorphic adenoma historical perspective|Historical Perspective]]== |
| *The pathogenesis of pleomorphic adenoma is characterized by an admixture of polygonal epithelial and spindle-shaped myoepithelial elements.
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| *The mutation on PLAG1 gene has been associated with the development of pleomorphic adenoma.
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| *On gross pathology, characteristic findings of pleomorphic adenoma, include:
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| :*May have cartilaginous appearance
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| :*Typically well-circumscribed
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| *On microscopic histopathological analysis, characteristic findings of pleomorphic adenoma, include:
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| :*Mixture of [[epithelial]] and [[myoepithelial]] elements
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| :*Background stroma that may be mucoid, mixed, cartilaginous or hyaline
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| :*Epithelial elements may be arranged in duct-like structures, sheets, clumps and/or interlacing strands and consist of polygonal, spindle or stellate-shaped cells (hence pleomorphism)
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| :*Tumor is usually enveloped by a fibrous capsule
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| ==Causes== | | ==[[Pleomorphic adenoma classification|Classification]]== |
| *Common causes of pleomorphic adenoma, include:
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| ==Differentiating Pleomorphic Adenoma from Other Diseases== | | ==[[Pleomorphic adenoma pathophysiology|Pathophysiology]]== |
| *Pleomorphic adenoma must be differentiated from other diseases that cause dry-mouth, single-nodular parotid mass, and dysphagia, such as:
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| :*Warthin tumour
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| :*Mucoepidermoid carcinoma
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| :*Myoepithelioma
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| :*Adenoid cystic carcinoma
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| ==Epidemiology and Demographics== | | ==[[Pleomorphic adenoma causes|Causes]]== |
| *Pleomorphic adenoma is common
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| *Pleomorphic adenoma accounts for 60% of all parotid gland tumors, and it represents 45-75% of all salivary gland neoplasms.
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| *The incidence of pleomorphic adenoma is approximately 2-3.5 per 100,000 individuals worldwide.
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| ===Age=== | | ==[[Pleomorphic adenoma differential diagnosis|Differentiating Pleomorphic Adenoma from other Diseases]]== |
| *Pleomorphic adenoma is more commonly observed among patients aged [age range] years old.
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| *Pleomorphic adenoma is more commonly observed among [elderly patients/young patients/children].
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| ===Gender===
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| *[Gender 1] are more commonly affected with pleomorphic adenoma than [gender 2].
| | ==[[Pleomorphic adenoma epidemiology and demographics|Epidemiology and Demographics]]== |
| * The [gender 1] to [Gender 2] ratio is approximately [number > 1] to 1.
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| ===Race===
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| *There is no racial predilection for pleomorphic adenoma.
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| ==Risk Factors== | | ==[[Xyz risk factors|Risk Factors]]== |
| *Common risk factors in the development of pleomorphic adenoma, include:
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| == Natural History, Complications and Prognosis==
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| *The majority of patients with pleomorphic adenoma remain asymptomatic for years.
| | ==[[Pleomorphic adenoma screening|Screening]]== |
| *Early clinical features include dry mouth, difficulty swallowing, and a palpable single nodular mass.
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| *If left untreated, patients with pleomorphic adenoma may progress to develop malignant transformation.
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| *Common complications of pleomorphic adenoma, include:
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| *If there is a malignant transformation, prognosis is generally poor, and the 5- year survival rate of patients with pleomorphic adenoma is approximately 30%.
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| == Diagnosis == | | ==[[Pleomorphic adenoma natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
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| === Symptoms === | | ==Diagnosis== |
| *Pleomorphic adenoma may be initially asymptomatic.
| | [[Pleomorphic adenoma diagnostic study of choice|Diagnostic study of choice]] | [[Pleomorphic adenoma history and symptoms|History and Symptoms]] | [[Pleomorphic adenoma physical examination|Physical Examination]] | [[Pleomorphic adenoma laboratory findings|Laboratory Findings]] | [[Pleomorphic adenoma electrocardiogram|Electrocardiogram]] | [[Pleomorphic adenoma x ray|X-Ray Findings]] | [[Pleomorphic adenoma echocardiography and ultrasound|Echocardiography and Ultrasound]] | [[Pleomorphic adenoma CT scan|CT-Scan Findings]] | [[Pleomorphic adenoma MRI|MRI Findings]] | [[Pleomorphic adenoma other imaging findings|Other Imaging Findings]] | [[Pleomorphic adenoma other diagnostic studies|Other Diagnostic Studies]] |
| *Symptoms of pleomorphic adenoma may include the following:
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| :*Dry mouth
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| :*Dysphagia
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| :*Painful chewing
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| === Physical Examination === | | ==Treatment== |
| *Patients with pleomorphic adenoma usually are well-appearing.
| | [[Pleomorphic adenoma medical therapy|Medical Therapy]] | [[Pleomorphic adenoma surgery|Surgery]] | [[Pleomorphic adenoma primary prevention|Primary Prevention]] | [[Pleomorphic adenoma secondary prevention|Secondary Prevention]] | [[Pleomorphic adenoma cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Pleomorphic adenoma future or investigational therapies|Future or Investigational Therapies]] |
| *Physical examination may be remarkable for:
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| :*Single, mobile, and painless nodular mass.
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| :*Eversion of the ear lobe
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| :*[finding 3]
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| :*[finding 4]
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| | ==Case Studies== |
| === Laboratory Findings === | | [[Pleomorphic adenoma case study one|Case #1]] |
| *There are no specific laboratory findings associated with pleomorphic adenoma.
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| ===Imaging Findings===
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| *MRI is the imaging modality of choice for pleomorphic adenoma.
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| *On CT, characteristic findings of pleomorphic adenoma, include:
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| :*Smooth, and well-marginated tumors
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| :*The attenuation values of the mass are usually homogeneous and higher than that of the surrounding gland
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| :*Tumor enhancement is variable and can result in a missed diagnosis if delayed images are not acquired
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| :*Pleomorphic adenomas are poorly enhancing in the early phase of contrast enhancement, though the amount of enhancement increases over time).
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| *On MRI, characteristic findings of pleomorphic adenoma, include:
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| :*Pleomorphic adenomas are usually well-circumscribed
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| :*Homogeneous masses with low intensity on T1-weighted images and high intensity on T2-weighted images.
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| :*They commonly have a rim of decreased signal intensity on T2-weighted images.
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| :*After gadolinium enhancement, the tumors are homogeneously enhancing unless they are large.
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| ====Gallery====
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| <gallery perRow="3">
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| Image:Pleomorphic adenoma MRI 101.jpg|MRI: A right parotid pleomorphic adenoma [http://www.radswiki.net Images courtesy of RadsWiki]
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| Image:Pleomorphic adenoma MRI 102.jpg|MRI: A right parotid pleomorphic adenoma [http://www.radswiki.net Images courtesy of RadsWiki]
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| Image:Pleomorphic adenoma MRI 103.jpg|MRI: A right parotid pleomorphic adenoma [http://www.radswiki.net Images courtesy of RadsWiki]
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| Image:Pleomorphic adenoma MRI 104.jpg|MRI: A right parotid pleomorphic adenoma [http://www.radswiki.net Images courtesy of RadsWiki]
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| Image:Pleomorphic adenoma MRI 105.jpg|MRI: A right parotid pleomorphic adenoma [http://www.radswiki.net Images courtesy of RadsWiki]
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| Image:Pleomorphic adenoma PET 106.jpg|PET: A right parotid pleomorphic adenoma [http://www.radswiki.net Images courtesy of RadsWiki]
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| </gallery>
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| === Other Diagnostic Studies ===
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| *Pleomorphic adenoma may also be diagnosed using [[fine needle aspiration]] (FNA) and core needle biopsy.
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| *Findings on [[fine needle aspiration]] (FNA) and core needle biopsy, include:
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| == Treatment ==
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| === Medical Therapy ===
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| *There is no treatment for pleomorphic adenoma; the mainstay of therapy is surgery.
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| *In some cases, patients with pleomorphic adenoma can receive medications to stimulate saliva production, such as:
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| :*Pilocarpine
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| :*Cevimeline
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| === Surgery ===
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| *Surgery is the mainstay of therapy for pleomorphic adenoma.
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| *Surgical excision in conjunction with pre-surgical biopsy is the most common approach to the treatment of pleomorphic adenoma.
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| *The recurrence rate after surgery will depend on the histological subtype. Mixed pleomorphic adenomas have a higher recurrence rate.
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| === Prevention ===
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| *There are no primary preventive measures available for pleomorphic adenoma.
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| *Once diagnosed and successfully treated, patients with pleomorphic adenoma are followed-up every 6 or 12 months.
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| ==References==
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| {{Reflist|2}}
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| [[Category:Disease]]
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| [[Category:Oral pathology]]
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| [[Category:Oncology]]
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