Post on 15-Apr-2017
CLASSIFICATION OF PAROTID GLAND
TUMOURSPLEOMORPHIC ADENOMA
ANATOMYPara- around
otis-ear
Largest salivary gland
Parts – superficial (80%) , deep (20%)
Duct – Stensen’s
HISTOLOGY
FACIAL NERVE
FACIOVENOUS PLANE OF PATEY
BLOOD SUPPLY: External carotid artery
VENOUS DRAINAGE : External jugular vein
LYMPHATIC DRAINAGE : Deep cervical nodes
One subtype, Membranous BCA- Appears hereditary.Often occurs in combination with skin appendage tumors- Dermal
Cylindromas & Trichoepitheliomas.Multiple bilateral tumors- Because these tumors often bear a
histopathologic resemblance to the skin tumors- Dermal analogue tumors.
Gross pathology:
Round to ovoid, well-circumscribed, with smooth surface capsule, firm in consistency- similar to lymph node.
Membranous Basal cell adenoma- Multinodular.Cut surface- homogenous, solid appearance that may be
interrupted by cysts of varying sizes, filled with brown/ red mucinous or blood, gray white to pink red or brown in color.
(a)Clinical examination: Small nodule behind the left ear. (b)basaloid cells in nests sheets and trabeculae (PAP stain; ×100). (c) peripheral palisading of cells (red arrows) and bare nuclei in
background (PAP, x400)); (d) basement membrane material around cell clusters (green arrows) (PAP,
x400
Trabecular type :
Narrow epithelial islands forming an interconnecting cord-like architecture- reticular pattern.
Tubular type.
Prominent multiple duct-like structures with intraluminal eosinophilic secretion occurs in conjugation with trabecular pattern to form a trabeculotubular patternLeast common
Inner cuboidal ductal cellsOuter layer of basaloid cells
2 cells
A number of salivary gland tumors can be characterized
microscopically by a papillomatous pattern.
The sialadenoma papilliferum, intraductal papilloma , and
inverted ductal papilloma are three rare salivary tumors
that also show unique papillomatous features.
viral - human papillomavirus
DUCTAL PAPILLOMAS (SIALADENOMA PAPILUFERUM; INTRADUCTAL PAPILLOMA; INVERTED DUCTAL PAPILLOMA)
Histopathologic Features
Sialadenoma papilliferum is somewhat similar to the squamous
papilloma , exhibiting multiple exophytic papillary projections that are
covered by parakeratotic stratified squamous epithelium.
This epithelium is contiguous with a proliferation of papillomatous
ductal epithelium found below the surface and extending downward into
the deeper connective tissues.
Sialadenoma papilliferum demonstrating the typical exophytic papillary surface and deeper ductal components.
Gross pathology:Varies from discrete encapsulated nodule to lesions that
are circumscribed but encapsulated.Sometimes multifocalPink-tan to tan, brown or yellowSometimes cystic spaces with gelatinous material seen
Mucous cells- vary in shape, abundant pale foamy cytoplasm that stains positive for mucin stains.
- relatively large, may assume round, cuboidal, ovoid, columnar or goblet shapes.
- stains positive for mucicarmine and PAS stain.Epidermoid cells- squamous features, polygonal shape.Intermediate cells- larger than basal cell, smaller than
squamous cell. Proginitor of epidermoid and squamous cells.
Clear cells- larger, polygonal and defined cytoplasmic borders.
Mucus cells - mucicarmine stain,
Clear cells - PAS
Tubular pattern:Tubular structure that are lined by stratified cuboidal
epithelium.Longitudinal section- ductal structures are viewed as ducts or
tubules.Lumina contains mucinous substance- PAS positiveCribriform pattern may exist with tubular pattern.
Adenoid cystic carcinoma.
Tubular variant showing morphologically clear abluminal cells.
Solid pattern:Solid groups of cuboidal cells with little
tendency towards ducts or cyst formation.Arranged in nests or sheets of varying size
and shape.Areas of necrosis seenCellular pleomorphism, mitosis observed.
Adenoid cystic carcinoma.
Solid variant higher power showing scattered duct-like structures within the tumor sheet.
Adenoid cystic carcinoma. The tumor cells aresurrounded by hyalinized material
Adenoid cystic carcinoma. Perineural invasion.
Dedifferentiation of adenoid cystic carcinoma- Recently defined, rare varient.- characterized histologically by 2 component1. Conventional low grade adenoid cystic carcinoma2. high grade dedifferentiated carcinoma. Because of frequent recurrence and matastasis, the
clinical course is short, similar to AdCC with a predominant solid growth pattern.
Histologically low grade AdCC merges gradually into extensive dedifferentiated component that is composed of solid sheets and cords of anaplastic tumor cell with focal gland formation..
p53 gene alteration plays a pivotal role.
Varients
Epithelial myoepithelial carcinoma (EMEC) is a rare low-grade malignant salivary gland neoplasm.
less than 1% of all salivary gland neoplasms.ORIGIN: intercalated ductA malignant tumor composed of variable proportions of two
cell types, which typically form duct-like structures.The biphasic morphology is represented by an- Inner layer of darker cells, that represent intercalated duct
epithelial component- Outer layer of clear, myoepithelial-type cells.
EPITHELIAL MYOEPITHELIAL CARCINOMA
Higher magnification showing luminal intercalated Duct like cells and abluminal clear cells.
Differential diagnosis:Pleomorphic adenomaClear cell tumorsClear cell oncocytomaMyoepithelial carcinomaClear cell myoepitheliomaMucoepidermoid carcinomaMalanoma Adenoid cystic carcinoma
Recently recognized type of salivary malignancy that was first
described in 1983.
Evans and Batsakis first used the term
PLGA occurs almost exclusively in the minor salivary glands
Characterized by: Bland, uniform nuclear feature, diverse by
characteristic architecture, infiltrative growth and perineural
invasion.
POLYMORPHOUS LOW-GRADE ADENOCARCINOMA
(LOBULAR CARCINOMA; TERMINAL DUCT CARCINOMA)
Gross pathology:Firm, circumscribed, but non-encapsulated, yellow tan
lobulated nodule, average size 2.2cms.Bony invasion may be seem in large lesion in the hard patate,
may impinge upon the maxillary bone and cause bone resorption and laterally medullary invasion
Gross image shows bone invasion in a large tumor in the hard palate
Histopathologic features:
Characterized by: Infiltrative growth with diverse morphology
& Uniform nuclear appearance
At low power, the tumor sometimes appears well circumscribed.
peripheral cells are usually infiltrative, invading the adjacent
tissue in a single- file fashion.
Difference growth pattern- hence the name polymorphous.
Variety of growth patterns- solid, ductal, cystic, tubular or
cribriform
Tumor stroma- varies from mucid to hyaline and in some areas
separated by fibrovascular stroma.
In some tumors, a cribriform pattern can be produced that
mimics adenoid cystic carcinoma .
Mitotic figures are uncommon.
Perineural invasion common.
CLASSIFICATION OF PAROTID GLAND TUMOURS
EPITHELIAL( 90%)
NONEPITHELIAL HemangiomaLymphangiomaNeurofibroma
• MALIGNANT LYMPHOMA – NHL TYPE
EPITHELIAL (90%)BENIGN (ADENOMAS)
Pleomorphic adenomaMonomorphic adenoma
Warthin’s tumour (adenolymhoma)Oncocytoma ( oxyphil adenoma )Basal cell adenoma
EPITHELIAL ( 90% )MALIGNANT
LOW GRADE Acinic cell
carcinomaAdenoid cystic
carcinomaLow grade
mucoepidermoid carcinoma
• HIGH GRADE• Adenocarcinoma
• Squamous cell carcinoma
• High grade mucoepidermoid carcinoma
CASEA 45 yr old femaleC/0 – slow growing, painless
swelling below the left side of ear for the past 5 months
O/e – 5x3 cm,oval, lifting the ear lobule
No localised warmth, not tender Surface-smooth, Margins- well
defined. Retromand groove oblit. Variable consistency. Mobile Not adherent to skin, masseter
muscle No signs suggestive of facial N inv Examination of oral cavity is normal
FNAC : shows ductal cells, chondromyxoid matrix and myoepithelial cells
DIAGNOSIS : PLEOMORPHIC ADENOMA
PLEOMORPHIC ADENOMAMIXED TUMOUR
SITE : MC: PAROTID GLAND ( 90%)- MC –Tail of gland
Submandibular gland (7%) Minor salivary glands-MC : Palate
Occurs more commonly in females (3:1) AGE : any age . MC : 40-50yrs Usually unilateral
PATHOLOGYBENIGN TUMORTumor capsule-well formed, but incompleteTiny excrescences (pseudopods) project
outside.Give rise to recurrences.
GROSS :CUT SECTION:
MICROSCOPIC APPEARANCE2 groups of cells :Well differentiated
epithelial cells-acini/cords/sheets
Spindle/stellate cells Abundant intercellular
mucoid material-resembles cartilage
Pleomorphic stromaNo necrosisRarity of mitotic figures
CLINICAL FEATURES Painless slow growing swellingIn the parotid both lobes involved. If only deep
lobe involved – DUMB BELL TUMOURDysphagia if deep lobe is involvedDeviation of uvula&pharyngeal wall towards
midline-deepDeep lobe swelling passes through PATEY’S STYLOMANDIBULAR TUNNELRaised ear lobuleCannot be moved abv zygomatic bone-CURTAIN
SIGNFACIAL NERVE NOT INVOLVED
INVESTIGATIONFNAC – IMPORTANT AND DIAGNOSTIC
OPEN BIOPSY – CONTRAINDICATEDDUE TO : chance of injury to facial nerve,seedling & high chance of recurrence,Parotid fistula formation
CT SCAN
MRI
MANAGEMENTTumor is RADIO RESISTANTSURGERY :ENUCLEATION –avoided. High recurrence.TOC : SUPERFICIAL PAROTIDECTOMY – PATEY’S OPERATION( if supf lobe alone involved)
TOTAL CONSERVATIVE PAROTIDECTOMY (If both lobes involved)FACIAL NERVE IS PRESERVED
COMPLICATIONSRECURRENCE ( 1 – 5 %)
MALIGNANCY3-5 % IN EARLY TUMORS10% IN LONG DURATION( >15
YRS)
RECURRENCE AFTER SURGERYDUE TO : SpillageInadequate marginRetained pseudopodsMulticentricityImproper technique
Recurrent tumor is multinodular without capsule
Marker to predict recurrence : MUC1/DF3
CARCINOMA IN EX PLEOMORPHIC ADENOMALong standing Pl.adenoma-malignant
transformationRecent increase in sizePain , nodularityInvolvement of skin, ulcerationInvolvement of masseterInvolvement of facial nerveNeck lymph nodeRestriction of jaw movements
TAKE HOME MESSAGEMOST COMMON TUMOUR OF PAROTID
FACIAL NERVE IS NOT INVOLVED
TOC : SUPERFICIAL PAROTIDECTOMY
FACIAL NERVE IS PRESERVED.
CARCINOMA IN EX PLEOMORPHIC ADENOMA.