Download - ch 14 part 2
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POLYMORPHOUS LOW GRADE ADENOCARCINOMA AGE CHANGES IN SG-minor SG, mostly palate-good prognosis-unpredictable potential to metastasize in 15% cases
in weight of parotid & submandibular glands relatedto atrophy of secretory tissue & replacement byfibrofatty tissue
Similar changes in labial minor SG
Oncocyte change in ductal epithelium
in flow rate of submandibular gland
Histopathologic:-variety of growth pattern within the same lesion
Solid
Tubular Papillary
Cribriform-cytologically uniform-bland with infrequent mitoses-lack of atypia-D/D adenoid cystic carcinoma (both show perinueralinvasion)
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PLEOMORPHIC ADENOMA (MIXED TUMOR)Commonest SG tumor
:: 60-65% parotid:: 45% minor SG
7% originate in minor SG esp palatalOld ages, femaleUsually solitaryRecurrences may be multifocal
Clinicalfeatures
-Slowly growing, painless, rubbery swellingwith intact overlying skin or mucosa-pts may be aware of lesion for several yrs
Histopathologicfeatures
-compose of cells of epithelial &myoepithelial origin-great variety with complex intermingling ofcomponents & mesenchyme-like areas-although benign, CT capsule is x alwayscomplete-clearly demarcated, but apparently
isolated nodules may be seen within oreven outside the capsule, giving theimpression of invasive growth-serial sections show that these representoutgrowth of the main mass-These islands explain the need for excisionwith a margin to avoid recurrence-variation in arrangement of epithelial &stromal components btwn different tumors& within different areas of same tumors-epithelial components may be arranged in
duct-like structures sheets
clumps
interlacing strands
Duct
surrounded
by
Dilate
d
Kerati
n
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WARTHIN TUMOR(PAPILLARY CYSTADENOMA LYMPHOMATOSUM)
Mostly parotidSlow-growingMultifocalBilateral (5-10%)Old ageMostly frm residual salivary duct epithelium entrappedwithin lymp nodes during dvlpmnt
Clinical
features
Gross appearance:
-multiple, irregular cystic spaces of variable sizecontaining mucoid material-lining of cyst has small projections (papillary structures)
Histopathologicfeatures
Multiple, irregular cystic spaces containing mucoidmaterial separated by papillary projections of tumortissue
Tumor consists of:
Epithelial component: double-layered epitheliumlining cystic spaces in papillary arrangement
Lymphoid component within stroma, may containgerminal centers
Epithelial cells have granular cytoplasm rich in abnormalmitochondria, resembling oncocytes
Cyst
ic Lympho
id tissue
Double
layer of
epitheliu
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BASAL CELL ADENOMA ONCOCYTOMA CANALICULAR ADENOMA DUCTALPAPILLOMAS
-1-2% of all SG tumor-79% parotid, 20% upper lip-Peak incidence in 7th decade
-rare-usually in parotid->60 yrs of age
->50 yrs of age-almost all cases in upper lip-no clinical significance-x represent invasive growth
-rare-several subtypes
-Consist of cytologically uniform basaloidcells arranged in variety of patterns-well-encapsulated
-thin capsule-consists of oncocyte
-consists of anastomosing strands ofbasaloid epithelial cells arranged incanalicular structures-partly or grossly cystic due todegeneration of loose vascularstroma-in some cases, multiple microscopicfoci of adenomatous change seensurrounding minor SG
-papillary structureprojecting into theductal system
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MUCOEPIDERMOID CARCINOMA
10% of all SG tumors
major SG: mostly parotid
minor SG: mostly palatal
highest incidence in 4th & 5th
decade
low grade MEC 1
low grade MEC 2
Low grade MECi. Well-differentiatedii. Mucous & epidermoid cells
predominateiii. No cellular pleomorphismiv. Often cystic, cyst lined by mucous-
secreting cellsv. Epidermoid cells present in strands
or clumps, show keratinizationvi. Rupture of mucin-containing cyst
lead to inflammationvii. Advance on a broad, pushing front
low grade MEC 3
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Clinical features:
similar to pleomorphic adenoma
grossly cystic tumors may befluctuant
more aggressive tumors maycause pain & ulceration
high grade MEC 1
High grade MECi. poorly-differentiatedii. epidermoid & intermediate cells
predominateiii. nuclear & cellular pleomorphism,
atypiaiv. cystic spaces x prominentv. difficult to differentiate frm SCCvi. ill defined & highly infiltrative
Histopathologic features:3 types of cells1. Squamous (epidermoid)2. Mucous3. Intermediate
relative proportions & arrangements ofcell types are used to distinguish btwn:
High grade MEC
Low grade MEC
Prognosis-low grade tumor rarely metastasize-however, behavior cannot be accuratelypredicted frm histopathology
-overall 5-yr survival rate: 70%-low grade tumors 5-yr survival rate: 95%
Local recurrence:
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OTHERS SGCARCINOMA
ACINIC CELL CARCINOMA CARCINOMA ARISING IN PLEOMORPHIC ADENOMA
1. ADENOCARCINOMA-relatively uncommon-1% or less of all bodymalignancies-5% of head n neckmalignancies-most common in majorSG esp parotid-however! Ratio ofmalignant to benign inminor SG is higher than inmajor
*not otherwise specified(NOS)
-Uncommon-accounts for 2-3% of parotid tumors-low grade malignancy-80-100% 5-yr survival rates for well-differentiated tumors-65% 5-yr survival rates for poorly-differentiated tumors
-known as carcinoma ex pleomorphic adenoma-3% of all SG tumors-almost all arises in parotid or submandibular longstanding tumors-histological dx requires evidence of pre-existingpleomorphic adenoma-malignant component may be an:
adenocarcinoma
undifferentiated carcinoma
other types of SG carcinoma-when the malignant part is confined within pre-existingtumor, prognosis is excellent-poor prognosis when there is infiltration-some mixed tumors arise as malignant de novo
-spectrum of histopathologicalappearances-most common: sheets or an acinargrouping of large, polyhedral cells withbasophilic, granular cytoplasm (similar to
serous acinar cells) hence the name!
2. EPITHELIALMYOEPITHELIALCARCINOMA
3. BASAL CELLADENOCARCINOMA
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ADENOID CYSTIC CARCINOMA-middle-aged & elderly-30% minor SG, 6% major (parotid)
Histological features:-wide spectrum of appearance
-most common: epithelium arranged as ovoid & irregularly shaped islands, or
anastomosing cords & strands in scanty CT stroma
-numerous microscopic cyst-like spaces within epithelial islands cribriformor Swiss cheese pattern-epithelium consists of small, uniform, basophilic cells-rare mitoses-less common:
epithelium arranged in tubular or solid pattern-prominent infiltration & invasion of adjacent tissues, spread around & alongnerves-in maxilla, tumor may infiltrate along marrow spaces with no evidence ofbone destruction-perineural invasion
Clinical features:-slow enlarging tumors (like pleomorphicadenoma) but pain & ulceration are morecommon-parotid tumors present with facial palsy-neurological manifestation: infiltrate & spreadalong nerves
Prognosis:-radiotherapy used in inoperable cases, but xcure permanently-runs a prolonged clinical course & metastases
Tumo
r cell
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are late, usually to lungs-long term prognosis is poor-survival rate for parotid tumors
5-yrs: 75%
10-yrs: 40%
20-yrs: