This document provides information on cysts and tumors of the salivary glands. It discusses that salivary gland tumors represent 2-4% of head and neck neoplasms and are classified as benign or malignant. 70% originate in the parotid gland, with 75% of parotid tumors being benign. Salivary gland diseases are classified as neoplastic or non-neoplastic. Non-neoplastic diseases include developmental, infectious, obstructive, functional and metabolic disorders. Salivary gland neoplasms show histologic diversity and classifications include benign, malignant, soft tissue and hematolymphoid tumors. Tumor progression is a multistep process involving genetic changes that can result

1. GOOD MORNING
SURAJ NAIR
SENIOR LECTURER
Dept. of Pedodontics
Malabar dental college, Manoor

2. CYSTS AND TUMORS OF
SALIVARY GLANDS

3. INTRODUCTION
 Salivary glands are important exocrine glands
 Their prime function being secretion of saliva
 Tumors of salivary glands represent 2 to 4 %
of head and neck neoplasms
 They are broadly classified into benign and
malignant tumors

4.  70% of salivary gland tumors originate in
the parotid gland
 8 % in the submandibular glands
 22 % in the minor salivary glands and
sublingual

5.  75% of parotid tumors are benign
 50% of tumors of submandibular and 60-80%
of minor salivary gland tumors are malignant
 Pleomorphic adenomas are the most
common benign tumors comprising 85 % of
all salivary gland neoplasms

6. CLASSIFICATION
 Salivary gland diseases vary in their incidence
and they are usually classified into
Neoplastic
Non-neoplastic

7. CLASSIFICATION OF NON-NEOPLASTIC
SALIVARY GLAND DISEASES
 DEVELOPMENTAL
 Aplasia
 Hypoplasia
 Atresia
 Accessory salivary duct
 Diverticuli
 Polycystic disease of parotid gland

8.  INFECTIOUSAND INFLAMMATORY
 Bacterial
1 Acute sialadenitis
2 Chronic sialadenitis
 Viral
1 Mumps
2 HIV associated salivary gland diseases
3 EBV infection
4 Coxsackie A infection
5 Cytomegalic sialadenitis

9.  OBSTRUCTIVE AND TRAUMATIC LESIONS
1 Sialolithiasis
2 Extravasation cysts
3 Retention cysts
4 Fistula
5 Necrotizing sialometaplasia
6 Radiation induced sialadenitis
7 Pneumoparotitis

10.  FUNCTIONAL DISORDERS
1 Xerostomia
2 Sialorrhea
3 Cystic fibrosis
 ALLERGIC AND IMMUNOLOGICAL DISORDER
1 Allergic sialadenitis
2 Sjogrens syndrome
3 Mikulicz’s disease
4 sarcoidosis

11.  METABOLIC AND HORMONAL DISORDER
1 Sialosis
2 Acromegaly
 AGEING - Oncocytosis
 IDIOPATHIC
1 Necrotizing sialometaplasia
2 Benign cysts of parotid glands
3 Cheilitis glandularis

12. CLASSIFICATION OF SALIVARY
GLAND NEOPLASMS
 They are remarkable for their histologic
diversity
 They include :
 Benign
Malignant
 They may be of epithelial, mesenchymal and
lymphoid origin

13. Classification by Foote and
Frazell1954)
Benign Malignant
 Pleomorphic adenoma
 Oxyphil adenoma
 Sebaceous cell adenoma
 Benign lymphoepithelial
lesion
 Papillary cystadenoma
lymphomatosm
 Malignant mixed tumor
 Mucoepidermoid tumor
 Squamous cell carcinoma
 adenocarcinoma

14. Classification by Thackeray and
Sobin 1972
 Epithelial tumors :
 Pleomorphic adenoma
 Monomorphic adenoma
 Mucoepidermoid tumor
 Acinic cell tumor
 Carcinomas
 Adenoid cystic carcinoma
 Adenocarcinoma
 Epidermoid carcinoma
 Undifferentiated carcinoma

15.  Nonepithelial tumors
 Unclassified tumors
 Allied conditions
 Benign lymphoepithelial lesion
 Sialosis
 Oncocytosis

16. Revised classification by
WHO 2005
 Malignant
 Benign
 Soft tissue tumors
 Hematolymphoid tumors
 Secondary tumors

17.  Malignant epithelial tumors
Acinic cell carcinoma
Mucoepidermoid carcinoma
Adenoid cystic carcinoma
Epithelial myoepithelial carcinoma
Clear cell carcinoma
Basal cell adenocarcinoma
Sebaceous carcinoma
Cystadenocarcinoma
Oncocytic carcinoma
Salivary duct carcinoma
Myoepithelial carcinoma
adenocarcinoma

18.  Benign epithelial tumors
o Pleomorphic adenoma
o Myoepithelioma
o Basal cell adenoma
o Warthins tumor
o Oncocytoma
o Canalicular adenoma
o Sebaceous adenoma
o Lymphadenoma
o Ductal papillomas
o cystadenoma

19.  Soft tissue tumors
• Hemangioma
 Hematolymphoid tumors
• Hodgkin’s lymphoma
• Diffuse large B-cell lymphoma
 Secondary tumors

20. ETIOLOGY
1. VIRUSES : EBV – lymphoepithelial
carcinoma
2. RADIATION : high frequency of
mucoepidermoid carcinoma and warthins
tumor
3. OCCUPATION :
{Rubber, arsenic, plumbing, automobile and
cosmetics}

21. 4 LIFESTYLE AND NUTRITION
Smoking –Warthin’s tumor
Tobacco use and alcohol – no association
5 HORMONES

22. HISTOGENESIS
 Histogenic concepts that were evolved were
 Unicellular theory
 Bicellular theory
 Reverse cell hypothesis
 Multicellular histogenetic concept

23.  UNICELLULAR THEORY
 Proposed that the neoplasm arise from their
adult differentiated counterparts of salivary
gland units
 Theory was later rejected
* induction of neoplasm requires
dedifferentiation of already specialized cells

24.  BICELLULAR THEORY :
 Eversole in 1971
 Semipleuripotential theory
 Based on the embryonic development of
palatal minor salivary glands
 Eversole observed existence of reverse cell
during embryogenesis of palatal salivary
glands

26.  Palatal minor salivary glands develop as
downgrowth of bilayered ducts
 Inner layer develop from outer basal layer
 These basal layer was considered as reverse
cells
 Stem cells
 They are confined to basal region and
thought to cause tumors
 Rejected – lack of specificity

27.  REVERSE CELL HYPOTHESIS :
 Regezi and Batsakis i 1977
 Proposed that differentiated cell types in
mature salivary glands are incapable of
undergoing neoplastic alteration
 Stem (reverse )cells are solely at risk for
neoplastic transformation

28.  MULTICELLULAR HISTOGENETIC CONCEPT
 Dardick in 1991
 Proposed that any of the cells found in the
normal salivary system could probably serve as
the precursor for neoplasm
 Both in vitro and in vivo studies have shown
that mitotic figures are frequently seen in inner
cell layer

31. TUMOR PROGRESSION IN SALIVARY
GLAND TUMORS
 Multistep process
 Involves sequential accumulation of genetic
changes
 It may progress in many ways

32.  They are :
Malignant transformation of benign salivary
gland tumors
Progression from low grade to high grade
carcinoma
Dedifferentiation of a carcinoma to high
grade carcinoma with loss of original line of
differentiation
Stromal invasion

33. DEDIFFERENTIATION OF SALIVARY GLAND
TUMORS
 Transformation of salivary gland carcinoma
to a high grade carcinoma in which the
original line of differentiation is no longer
evident
 Acinic cell carcinoma – first to be reported

34.  Dedifferentiated component could be a form of
o High grade carcinoma
o Poorly differentiated carcinoma
o Undifferentiated carcinoma
Other tumors reported were –
• Mucoepidermoid carcinoma
• Adenoid cystic carcinoma
• Myoepithelial carcinoma
• Salivary duct carcinoma
• Hyalinizing clear cell carcinoma

35. GENETIC COMPONENTS
 Genetic changes that could mediate
dedifferentiation are p53 mutation, increased
cyclin D1 expression , loss of expression of Rb
protein and gene amplification

36. Thank
you