Head & Neck. Flashcards
Salivary glands tumor classification.
① Benign: pleomorphic adenoma (mixed tumor)
Warthin tumor
Oncocytoma
other adenomas( basal cell adenomas, canalicular adenomas)
ductal papilloma
② malignant: mucoepidermoid carcinoma, adenocarcinoma, Acinic cell carcinoma , others: Adenoid cystic carcinoma, malignant mixed tumor
Definition of pleomorphic Adenoma ?.
There are benign tumors consisting of a mixture of ductal ( epithelial cells) and myoepithilial cells hence show both mesenchymal & epithelial differentiation
Mostly parotid gland
Seen as epithelial elements dispersed throughout matrix along with myxoid, hyaline ,chondroid & osseous tissue
All neoplastic elements including those that appear mesenchymal are either of myoepithelial or ductal cell origin.
Morphology of pleomorphic adenomas
Round, well demarcated masses
Capsule- encapsulated but in palate capsule not fully developed expansion protrude into surrounding normal tissue
Cut sunface-gray white with blue myxoid translucent areas of chondroid ( cartilage like )
Histology - epithelial elements dispersed in a mesenchyme like background of myxoid tissue with islands of cartilage & bone.
Epithelial cells form well developed ducts by cuboidal to columnar epithelium with underlying layer of deeply chromatic small, myoepitheliel cells.
Epithelial dysplasia & mitotic figures absent
warthin tumor
Exclusively parotid gland, mostly in smokers, beingn
Papillary cystadenoma lymphomatosum
Morphology:
Round to oval, encapsulated
Transection-pale grey surface punctuated by cystic or cleft like spaces filled with mucinous (orserous sections
Microscopy- spaces are lined by double layer of neoplastic epithelial cells resting on dense lymphoid stroma bearing germinal centres too
Double layer of lining cells- upper layer- granular( as abundant mitochondria - called oncocytic) Cytoplasm pallisading columnar cells
Lower layer- cuboidal to polygonal cells
Secretory cells dispersed in columnar cell layer
