1. 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

2. 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

3. Warthin Tumour
Papillary Cystadenoma Lymphomatosum

4. 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

5. 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

6. 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

7. 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

10. Topics covered Premalignant lesions of oral cavity
Leukoplakia
Erythroplakia
Squamous cell carcinoma of oral cavity
Tumours of salivary gland