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Salivary gland Tumors Benign Malignant DR NAVEEN KASLIWAL ASSISANT PROFESSOR
Salivary gland Tumors • 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.
Benign Salivary Gland Tumors • PLEOMORPHIC ADENOMA • MONOMORPHIC ADENOMA • PAPILLARY CYSTADENOMA • ONCOCYTOMA
Pleomorphic Adenoma • 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.
Pleomorphic Adenoma 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.
Pleomorphic Adenoma 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.
Pleomorphic Adenoma 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 cont……d
Pleomorphic Adenoma • 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.
Pleomorphic Adenoma 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.
Monomorphic adenoma • 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: 1. The Basal cell Adenoma 2. Canalicular adenoma
Basal cell adenoma • 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 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.
Basal Cell Adenoma 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 arrangement.
Basal Cell Adenoma TREATMENT: • Enucleation or surgical excision can be done. • Recurrence is rare.
Canalicular Adenoma 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.
Canalicular Adenoma 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.
Canalicular Adenoma TREATMENT: • Enucleation or surgical excision can be done. • Recurrence is rare.