Salivary Gland tumors Parotid Submandibular Minor salivary glands
Pleomorphic Adenoma Benign Tumor Represent 60% of tumors in parotid – Most common tumor of major salivary glands. Mixed Tumor – Derived from a mixture of Ductal [ epithelial] and myoepithelial cells, showing epithelial and mesenchymal differentiation. Radiation – A risk factor!!
Pleomorphic Adenoma -Histology HETEROGENEITY Epithelial cells resembling ductal cells or myoepithelial cells arranged as ducts, acini , tubules, strands, sheets… Dispersed within mesenchyme – loose myxoid tissue of chondroid, foci of bone. There is no epithelial dysplasia/ mitotic activity.
Carcinoma Ex PleomorphicAdenoma Malignant mixed tumor Incidence of malignant transformation increases with duration of tumor. Adenocarcinoma / Undifferentiated carcinoma Overgrows preexisting pleomorphic adenoma. Diagnosis- traces of pleomorphic adenoma must be there. Most aggressive of all salivary gland neoplasms!!!!!
Warthin’s Tumour Second most common salivary gland neoplasm. Benign tumour Only tumour virtually restricted to parotid. More common in males Smoking - A risk factor!! 10% multifocal , 10% Bilateral.
Warthin’s Tumour - Gross Round to Oval Encapsulated Mostly arises in superficial parotid Cut section – Pale grey surface punctuated by cystic spaces filled with mucinous/ serous secretions.
Warthin’s Tumour -Histology Cystic spaces lined by double layer of neoplastic epithelial cells – surface palisade by oncocytic columnar cells resting on a layer of cuboidal cells these layers rest on a dense lymphoid stroma Papillary projections of lymphoepithelial elements into the cystic spaces Papillary Cystadenoma Lymphamatosum
Mucoepidermoid Carcinoma Malignant tumor Most common form of primary malignant tumour of salivary glands. Variable mixtures of squamous cells, mucus secreting cells, intermediate cells. Divided into Low , intermediate and high grade tumors. Radiation – A Risk factor !!
Mucoepidermoid Carcinoma - Gross • Grow up to 8cms • Though apparently circumscribed, lack well defined margins • On cut section. - Pale and grey white - Small mucin containing cysts.
Non Hodgkin’s Lymphoma uncommon tumor most often occurs in the parotid gland (70%) and belongs to MALT type Lymphoid proliferation of salivary gland REACTIVE MALIGNANTLymphoepithelial sialadenitis of NHL-MALT type cases derived from Sjogren Syndrome lymphoepithelial sialadenitis
Squamous cell carcinoma • True salivary gland primaries of squamous cell carcinoma are very rare • Most tumors of parotid gland are metastases to intraparotid lymph nodes from primaries in oral cavity, upper aerodigestive tract or skin • May represent malignant component of malignant mixed tumor or high grade mucoepidermoid carcinoma • Rapid growth with infiltration of surrounding structures, regardless of origin
To conclude….. Most common tumour 1. Of major salivary glands?? Pleomorphic Adenoma 2. Of minor salivary glands?? Adenoid Cystic Ca 3. Malignant tumour of salivary glands.?? Mucoepidermoid Salivary gland tumour 1. with strong predilection to invade nerves?? Adenoid Cystic Ca 2. associated with smoking?? Warthin’s tumor 3. with double layer of epithelial cells and lymphoid stroma?? Warthin’s tumor