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