1. Clinical presentation of parotid gland tumors

2. Pleomorphic adenoma of the parotid gland
Rounded, encapsulated mass/rarely exceed 6 cm Ө. C/S gray-white with myxoid and blue translucent areas of chondroid tissues

3. Pleomorphic salivary adenoma
The LP pleomorphic adenoma (mixed tumor) of salivary gland is shown extending into surrounding normal parotid gland*.

4. Epithelial duct-like structures are seen in loose and dense connective tissue stroma
The neoplastic ducts are surrounded by a
myxomatoid stroma. Also note the eosinophilic secretory product in the epithelial duct.

5. The glandular epithelium dominates this section.
Sheets of epithelial cells with some keratin "pearls" are evident in this section.

6. The stroma has a "cartilagenous" appearance; blood vessels are also prominent in this section.
Epithelial ducts in a dense c.t. stroma that resemble ostoid material, an observation supported by the nearby calcified bone.

7. Recurrent mixed salivary gland tumor
Recurrence of mixed tumor Although this is a bizarre example, it demonstrates well the multinodularity so typical of recurrent tumor. The reason for this is that during the first surgical procedure many small pieces of tumor were distributed throughout the operative site and each
formed the nidus for a recurrent mass.

8. Warthin tumor
Round to oval encapsulated mass, up to 5 cm Ө/pale gray surface punctuated by cleft-like spaces/ filled with a mucinous/serous secretion.
These tumours are multicystic. The cysts are filled with mucus, as indicated. They are benign tumours and are the second most frequent tumour of the parotid gland, following pleomorphic adenoma.

9. Cystic spaces narrowed by lymphoepithelial papillary structures

10. - Double layer of oncocytic epithelial cells resting on a lymphoid stroma/germinal centers
- Oncocytes: eosinophilic granular cytoplasm: stuffed with mitochondria

11. MUCOEPIDERMOID CARCINOMA
Sheets of squamous and mucous-secreting cells

12. Adenoid cystic carcinoma palate
In the minor salivary glands esp. palate (the most common malignant tumor)

13. Adenoid cystic carcinoma
Small cells with dark nuclei & scant cytoplasm
Disposed in cribriform pattern
Spaces filled with mucin & excess BM material

14. Adenoid cystic carcinoma
Nerve
Adenoid cystic carcinoma with prominent perineurial invasion.

15. Acinic cell ca microfollicular
The cells are reminiscent of normal acinar cells with basophilic granular cytoplasm. They are disposed as lobules with glandular arrangement (as in normal salivary glands).