Pleomorphic adenoma

• Clinical features– Painless– Slow growing– Mobile– Discreet masses– Carcinoma arising in a pleomorphic adenoma

is called Carcinoma ex pleomorphic adenoma or malignant mixed tumour

Pleomorphic adenoma

• Clinical features– Incidence of Malignant transformation increases

with duration of tumour• 2% for tumours less than 5 years• 10% for tumours more than 15 years duration• Usually adenocarcinoma or undifferentiated

carcinoma• Tumours are very aggressive • For a diagnosis of Carcinoma ex Pleomorphic

adenoma, recognizable traces of pleomorphic adenoma must be present

Warthin Tumour

• Papillary Cystadenoma Lymphomatosum

Warthin Tumour

• Benign neoplasm• Second most common salivary gland

tumour• Arises only within the Parotid• Occurs more commonly in males• Fifth to seventh decades• 10% multifocal; 10% bilateral• Smokers have 8 times the risk of non

smokers

Warthin Tumour

• Morphology - Gross– Round to oval– Encapsulated masses– 2 to 5 cms– Superficial parotid gland– Cut surface pale gray puctuated by narrow

cystic spaces filled with mucin or serous secretion

Warthin Tumour

• Morphology - Microscopy– Cystic spaces lined by double layer of

neoplastic epithelial cells– Neoplastic cells rest on a dense lymphoid

stroma sometimes with germinal centers– Spaces narrowed by presence of polypoidal

lymphoepithelial projections

Warthin Tumour

• Morphology - Microscopy

– Double layer of epithelial lining cells

• Surface palisade of columnar cells having abundant, finely granular, eosinophilic cytoplasm - oncocytic appearance

• These cells rest on a layer of cuboidal cells

• Oncocytes are epithelial cells stuffed with mitochondria

• Occasionally foci of squamous metaplasia

Topics covered

• Premalignant lesions of oral cavity– Leukoplakia– Erythroplakia

• Squamous cell carcinoma of oral cavity• Tumours of salivary gland