1. Tumors and Tumor-like Lesions
of Salivary Gland

2. MAJOR FEATURES OF SALIVARY GLANDS
Parotid:
Largest major salivary gland
Stensen's duct
Serous
Facial nerve
Submandibular gland
Wharton's duct
Mucous-Serous
Sublingual gland
Bartholin's duct, Rivinus ducts
Small salivary glands
Mucous

3. Intercalated duct
Acinus, serous
Striated duct
Acinus, mucous

5. Submandibular gland-mucinous and serous

6. Serous, mucinous glands
EM-serous cell

7. Salivary Gland Tumor: Benign vs. Malignant
Pleomorphic adenoma (mixed tumor)
Papillary cystadenoma lymphomatosa
Oxyphil adenoma
Sebaceous cell adenoma
Benign lymphoepithelial lesion
Unclassified
Malignant mixed tumor
Mucoepidermoid tumor
Squamous cell carcinoma
Adenocarcinoma
Adenoid cystic
Trabecular or solid
Anaplastic
Mucous cell
Pseudoadamantine
Acinic cell
Unlassified

8. Salivary Gland Tumors 2% of head and neck neoplasm
Parotid: 80% overall; 80% benign
Submandibular: 15% overall; 50% benign
Sublingual/minor: 5% overall; 40% benign

9. Benign Salivary Gland Tumor

10. Salivary Gland Carcinoma

11. Pleomorphic Adenoma (Benign Mixed Tumor)
PA account for 25-30% of all salivary gland tumors % of all parotid tumor; 40-60% submandibular gland; 40-70% minor salivary gland tumor. F:M=1.9:1
PAs are epithelial-derived tumors composed of cells with epithelial and mesechymal-like features. They often display both ductal and myoepithelial differentiation, but less frequently are predominantly ductal or myoepithelial and may mimic monomorphic adenomas, such as myoepithelioma, basal cell adenoma or canalicular adenoma.
Recurrence after surgery: <5%; due to finger-like tumor projections

12. Pleomorphic Tumor: Gross
Irregular, round to ovoid mass Well defined borders In major salivary gland: Incomplete fibrous capsule or unecapsulated. In minor salivary gland: Unencapsulated Homogeneous tan to white cut surface Hemorrhage and infarction on occasion

13. Anastomosing trabeculae Ducts Cysts lined by squamous epithelium
Pleomorphic adenoma
EPITHELIUM
Anastomosing trabeculae
Ducts
Cysts lined by squamous epithelium
STROMA
Fibrous interlacing bundles
Myxoid areas
Chondroid areas
Myxochondroid areas
Osseous areas
Fibrillar eosinophilic areas

14. Pleomorphic adenoma with capsular ingrowth

15. Pleomorphic adenoma: low cellularity, high cellularity, myoepithelial cells, and basal cells predominante

16. Pleomorphic adenoma: squamous metaplasia and chondrometaplasia

17. Pleomorphic Adenoma (Benign Mixed Tumor) of Palate

18. Carcinoma ex Pleomorphic Adenoma
Clinical & radiological features: rapid growth in preexisting lesion of long duration; pain and nerve paralysis; cystic change (CT); microcalcification (CT); regional lymph node enlargement
Pathologic features: elevated mitotic rate; tissue infiltrationm especially perineural invasion; necrosis; microcalcification; lymph node or distant metastasis; sclerosis with entrapment of epithelial elements

19. Carcinoma ex pleomorphic adenoma
Risk of malignancy in pleomorphic adenoma: 5-7%

20. Warthin’s Tumor (Papillary Cystadenoma Lymphomatosum) -1
Occurs only in the parotid gland
2nd most common benign parotid tumor
May be unilateral or bilateral
May occur as multiple lesions either synchronously or metachronously
More common in males (26:1)
More common in smokers
Occurs as a painless, sometimes fluctuant mass

21. Warthin’s Tumor (Papillary Cystadenoma Lymphomatosum) -2
May be associated with acute onset of pain and a sudden increase in size (papillary cystadenoma lymphomatosum syndrome)
Retrograde infection
Ear symptoms (tinnitus, deafness, earache)
Facial nerve paralysis
The ability to concentrate sodium pertechnetate (99mTc) is suggestive of Warthin tumor

22. Warthin’s Tumor (papillary cystadenoma lymphomatosum)

23. Warthin’s tumor
                                               

24. Oncocytoma Rare; 2.3% of salivary tumor 6th decade; M:F=1:1
Parotid: 78%
Submandibular: 8%
Minor salivary gland: palate, tongue, buccal mucosa

25. Mucoepidermoid Carcinoma
MEC: % of all salivary gland tumors, 12-29% of malignant salivary gland tumors; most common type of malignant minor salivary gland tumors
53-56% in major salivary gland with 85-88% in parotid
Most frequently seen in yrs-old; most common malignant salivary glands in children and adolescens under 20 yrs-old; F:M=3:2
44% patients with history of radiation

26. Mucoepidermoid Carcinoma –Grading (modified from Ellis GL et al)
Parameter (point of value): cystic component of <20% (+2); neural invasion (+2); necrosis (+3); 4 or more mitoses/10 hpf (+3); anaplasia such as nuclear pleomorphism and hyperchroamtism, increase N/C, prominent nucleoli (+4)
Grade: Low (0-4); Intermediate (5-6) and high (7-14)
Note: The grading tends to downgrade MEC. Additional paameters such as aggreesive pattern of infiltration, vascular/lymphatic invsion be included.

27. Mucoepidermoid Carcinoma, low-grade
The neoplastic cells were arranged into solid nests and islands, there was cyst formation. Mucicarmine stain did demonstrate focal intracellular mucin. The solid growth pattern, focal mucocytes and focal epidermoid cells supports the diagnosis of mucoepidermoid carcinoma. Lack of necrosis, anaplasia, neural invasion and a low mitotic count caused us to give this lesion a low grade designation. Histologic grade is associated with prognosis and these tumors have a favorable prognosis based on both histologic grade and anatomic location. Conservative excision that ensures tumor free margins is adequate therapy.

28. mucoepidermoid carcinoma, low-grade

31. Mucoepidermoid Carcinoma

32. Adenoid Cystic Carcinoma
A malignant epithelial neoplasm of ductal (lumial) and myoepithelial (abluminal) cells grwoing in cribriform, tubular, solid and cystic patterns More common in parotid gland;most common malignant tumor of intraoral salivary glands ; Female to male ratio, 3:2
Slow growing tumor; small tumors movable by palpation, larger tumors adherent to skin and soft tissues ;Tenderness and pain ;Facial nerve paralysis ;Mucosal ulceration

33. Adenoid cystic carcinoma

34. Acinic Cell Carcinoma
Acinic Cell Carcinoma is a rare salivary gland cancer, approx. 4% of all minor, and 2-4% of all major salivary gland tumors and approx. 13% of all malignancies of the parotid gland, and are rarely seen in other salivary tissues.
Acinic Cell Tumors are typically slow-growing, low-grade (highly differentiated) neoplasms that appear in all age groups, but are most common in women. Local and multiple recurrences may occur in up to half of patients. The most common sites of metastases are lungs and bone.Many authors consider Acinic Cell Carcinoma patients to have the most favorable outlook of all salivary gland patients, with survivals of 80-85% at 10 years.

35. Various histologc appearance
Recurrent actinic cell carcinoma

36. Papillary Cystadenocarcinoma of Salivary Gland
The majority of papillary cystadenocarcinomas have a biologic behavior similar to that of a benign neoplasm: recur infrequently,not to metastasize. The tumor lacked basophilic zymogen granules, typical of serous acinar cells. Both benign and malignant tumors often have broad "pushing" lobules with no significant cytologic atypia and high mitotic rate; therefore, classification of such lesions as benign or malignant is based on subjective evaluation. A papillary cystic salivary tumor not readily identifiable as a benign lesion is often regarded as a low-grade carcinoma, particularly with complex branching, bridging, or cribriform pattern.

37. Papillary cystadenocarcinoma of salivary gland

38. Papillary cystadenocarcinoma of salivary gland

39. Location(s): Lining mucosa. Clinical Features: Raised, bluish,
Mucocele & Ranula
Etiology: Trauma
Location(s): Lining mucosa.
Clinical Features: Raised, bluish,
translucent, fluctuant lesion.
Microscopic: Chronic inflammation
with macrophages surrounding spilled saliva.

40. Necrotizing Sialometaplasia-1
Uncommon disease; male:female=1.5-2:1, usually occurs in patients > 40 years old. It most commonly presents with a painful lesion of the hard palate, usually with ulceration. A self-limited condition and it probably results from ischemic changes involving the minor salivary glands and thus can be found in the nasal cavity, gingiva, lip, hypopharynx, maxillary sinus, and major salivary glands. There is a primary form which usually involves the minor salivary glands of the palate and is of unknown etiology.

41. Necrotizing Sialometaplasia-2
Histological: the lobular necrosis of the salivary gland tissue, preservation of the lobular architecture, squamous metaplasia of the residual ducts and acini, and temporal variability of the inflammatory cell infiltrate.
The importance in making this diagnosis rests with the pathologist distinguishing this disorder from a malignancy. Squamous cell carcinoma or mucoepidermoid carcinoma of the palate should never be made until necrotizing sialometaplasia is excluded.

42. Necrotizing Sialometaplasia

43. Necrotizing sialometaplasia

44. Necrotizing sialometaplasia

45. Non-Neoplastic Salivary Gland Disease
Many causes of salivary gland enlargement are unrelated to neoplasms. Sarcoidosis, mumps, malnutrition, iodine therapy and hepatic cirrhosis, are well-recognized causes for salivary gland enlargement. The probable autoimmune conditions -- Mikulicz's disease and Sjogren's syndrome are additional salivary gland disease. Probably the most common is sialadenitis secondary to duct obstruction. Although major salivary gland ducts may be obstructed by strictures, scar formation and tumor involvement, an occluding sialolith is the most frequent cause of obstruction.

46. sialolithiasis