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- Tumors that arise from the salivary gland may arise from the salivary
epithelium (the parenchyma) or the supportive stroma (mesenchymal)
- Benign parenchymal tumors are known as Adenomas
- Malignant tumors are known as adenocarcinomas .
- Salivary gland tumors may arise form any cellular component including
the basal cells ductal, striated interclated ducts, acini and the
myoepithelial cells.
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- PLEOMORPHIC ADENOMA
- MONOMORPHIC ADENOMA
- PAPILLARY CYSTADENOMA
- ONCOCYTOMA
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- It is the most common benign salivary gland tumor composed predominantly
by the proliferation of the myoepithelial cells and a wide spectrum of
the epithelial and the mesenchymal tissue component surrounded by a
distinctive capsule.
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- CLINICAL FEATURES:
- PA accounts for 60% of all parotid gland tumors,50% of submandibular
tumors and 25% of sublingual tumors
- PA is encountered in patients of all ages.
- PA is a slow growing tumor.
- It is soft or slightly firm on palpation and on larger gland it is
freely movable.
- In parotid glands the tumor id spherical and arises in the superficial
lobe as an obvious mass.
- In minor gland there is soft to slightly firm swelling without any
ulceration.
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- DIAGNOSIS:
- MRI is the most reliable source of diagnosis and to determine the extent
of the disease particularly in the major salivary glands.
- Biopsy has always been a best tool for the definitive diagnosis.
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- HISTOPATHOLOGY:
- In PA there is presence of a pronounced fibrous capsule. This is the
most important histological feature when distinguishing between the
benign and the malignant tumors
- Some lesions of the long standing lesions are multinodular and each
nodule is surrounded by the fibrous capsule.
- The tumor cells shoe wide variation of the cells involved that is why
the name pleomorphic has been given.
- The most prominent pattern contains the ductal and the myoepithelial
cells
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cont……d
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- Sheets of the myoepithelial cells loose there typical spindle shape
becoming polygonal with eccentric nuclei with hyalinized cytoplasm.
- Although PA,s are well capsulated it uncommon for the tumor cells to
perforate the capsule and creating new tumor foci.
- There is less than 1% chances of malignant transformation for those
which have undergone recurrences. The tumors are termed as Carcinoma ex.
Pleomorphic adenoma.
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- TREATMENT:
- Lobulectomy is done in the larger salivary glands.
- Enucleation is not done because of the chances of recurrence
(deposition) of exracapsular foci of tumor cells)
- PA,s of the lip are enucleated as there chances of recurrence are
minimal as some normal tissue is also excised with the tumor.
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- Monomorphic adenomas lack wide cellular diversity as seen in pleomorphic
adenomas.
- They are composed of single cell type that is why term monomorphic has
been used
- There are to distinct entities in this group:
- The Basal cell Adenoma
- Canalicular adenoma
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- Interclated ducts or the reserve cells are the source of this tumor.
- CLINICAL FEATURES:
- Occur in the major salivary glands
- 96% in the parotid gland and Rest of 4% in the other salivary glands
- They are painless and are slow growing.
- Major patients are over the age of 60 years.
- Basal cell adenomas of the minor salivary gland are usually present on
the upper lips, in elderly patients.
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- HISTOPATHOLOGY:
- They have well defined capsule composed of connective tissue.
- The cells isomorphic and basaloid in appearance.
- The nuclei is round to oval with a scanty and ill defined cytoplasm.
- The tumor cells are arranged in solid nests with the peripheral cells
often showing palisaded arrangment.
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- TREATMENT:
- Enucleation or surgical excision can be done.
- Recurrence is rare.
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- CLINICAL FEATURES:
- The lesion originates from the intraoral accessory salivary glands.
- It occurs in the upper lip and there are instances when it occurs on the
palate or the buccal mucosa.
- The tumor is a well circumscribed
firm nodule which is not fixed and moves through the tissues.
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- HISTOPATHOLOGY:
- There long strands or cords of
epithelial cells, arranged in a double row
- There cystic spaces of varying sizes enclosed by these cords.
- The cystic spaces are filled with eosinophilic coagulum.
- The supporting stroma is loose and fibrillar with delicate vascularity.
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- TREATMENT:
- Enucleation or surgical excision can be done.
- Recurrence is rare.
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