This document provides information on various benign tumours of the salivary glands, including pleomorphic adenoma, Warthin's tumour, oncocytoma, basal cell adenoma, canalicular adenoma, myoepithelioma, sebaceous adenoma, and ductal papillomas. It describes the location, histology, clinical features, differential diagnosis, and treatment for each tumour type. The most common benign salivary gland tumour is the pleomorphic adenoma, which can occur in the parotid, submandibular, and minor salivary glands. Surgical excision is typically the treatment.

1. MAHAK RALLI, ROLL NO. 42
BENIGN TUMOURS OF
SALIVARY GLANDS

2. PLEOMORPHIC ADENOMA
• Most common benign salivary neoplasm consisting
of cells exhibiting the ability to differentiate
epithelial cells (ductal and nonductal cells)
mesenchyme-like cells (chondroid, myxoid or
osseous)
• This results in different histopathologic patterns in the
tumours. Hence the name pleo- (meaning many)
morphic (meaning shape, form )

3. ETIOLOGY
• 60% of all salivary gland tumours
• 85% of these are found in the parotid gland, 8% in
submandibular gland and the remaining in
sublingual and minor salivary glands
• Histogenesis –
Numerous theories have been advanced.
Current theory- based on myoepithelial and reverse
cells of the intercalated ducts.

4. CLINICAL FEATURES
• Age- 30 to 50 years
• Gender- slight female predilection
• Location –superficial lobe of parotid > submandiblar
gland> palate
• Signs and symptoms
It is a slow growing and painless mass
Rarely ulcerates the overlying skin
In parotid gland, the tumour grows in posterior and
inferior aspect of superficial lobe measuring a few
cms.
In the submandibular gland, it is a well defined
palpable mass.

5. CLINICAL FEATURES
• When occuring in the parotid, the ear lobe of the
affected side might elevate.
• When observed in-situ, it is encased in
pseudocapsule and exhibits a lobulated surface.
• The palatal tumours are smooth-surfaced and
dome shaped masses.

6. Typical appearance of
pleomorphic adenoma
Removal of palatal tumour

7. PATHOLOGY
• Gross appearance
Firm, smooth mass within a pseudocapsule
• Histological appearance
Has both epithelial and mesenchymal cells
Stroma consists of chondroid, myxoid, osseous and
fibroid cells
There is presence of microscopic projections which
are necessary to remove, or they become the
cause for recurrence.

8. Neoplastic cells are seen arranged in ductal patterns, sheets and islands.
Stroma is delicately collagenous with myxoid areas.
Few cells show vacoular degenartion

9. Neoplastic cells are seen arranged in ductal patterns, sheets and islands.
Stroma is delicately collagenous with myxoid areas.
Few cells show vacoular degenartion

10. DIFFERENTIAL DIAGNOSIS AND
TREATMENT
• DIFFERENTIAL DIAGNOSIS
Adenolymphoma
Oncocytoma
Adenocarcinoma
Warthin’s tumour
• TREATMENT
Surgical removal of the tumour including adequate
margin
Superficial parotidectomy, if the tumour is affecting
the parotid gland
Removal of the entire submandibular gland may be
required if the submandibuar gland is affected

11. PAPILLARY CYSTADENOMA
LYMPHOMATOSUM
• Also known as Warthin’s tumour.
• Second most common benign tumour seen in the
parotid gland
• It is characterized by proliferation of both luminal
and non-luminal cells.

12. CLINICAL FEATURES
• Age- 60 to 70 years
• Gender- slight male predilection
• Location- parotid most commonly affected, inferior
and posterior to the angle of mandible
• Signs and symptoms-
It is a slow growing, painless nodular mass
It is firm in consistency or fluctuant
It can occur as a bilateral lesion (unique feature)
It is metachronous i.e appearing at different times,
not simultaneously.
Oncocytes take up technetium and is visible on Tc
99m scintiscans.

14. CLINICAL APPEARANCE

15. PATHOLOGY
• Gross appearance-
Tumour is smooth and has a well defined capsule.
Cut specimen shows cystic spaces filled with thick
mucinous material.
• Histological appearance-
Cyst formation with papillary projections in the cystic
spaces.
Inner luminal cells are tall, columnar and eoisnophilic
with palisaded nuclei.
Outer luminal cells are cuboidal or polygonal.
There is characteristic lymphocytic infililtration.

18. DIFFERENTIAL DIAGNOSIS AND
TREATMENT
• DIFFERENTIAL DIAGNOSIS
Pleomorphic adenoma
Oncocytoma
Parotid lymph node enlargement
• TREATMENT
Surgical excision involving a margin of normal tissue
In cases where a significant amount of superficial
lobe is affected, superficial parotidectomy is done.
Recurrence and malignant changes are rare

19. ONCOCYTOMA
• Less common benign tumour (<1%)
• The name is derived from presence of oncocytes.
• These cells resemble the apparently normal cells.
• Oncocytic cells are considered as somatic mutants
rather than new specific cell lineage.
• Oncocytic transformation of epithelial cells is not
degenerative but rather a redifferentiation of
epithelial cells which develope an increased but
unbalanced metabolism.

20. CLINICAL FEATURES
• Age- 50 to 80 years
• Gender- female predilection
• Location- parotid gland most commonly affected
• Signs and symptoms-
Discrete, encapsulated, slow growing mass
3-5cm in diameter
Painless and firm
Diffuse multinodular oncocytoma appears when
many nodular masses involve the entire gland
Can occur bilaterally
Rarely seen intraorally

21. Oncocytoma, clinical appearance

22. PATHOLOGY
• Gross appearance-
Non cystic and firm
• Histology-
Brown, granular eosinophilic cells with central nuclei
and arranged in sheets, nests or cord.
Oncocytes concentrate technetium and can be
visualized by Tc 99m scintigraphy
Malignant oncocytomas can occur and are
aggressive.

24. DIFFERENTIAL DIAGNOSIS AND
TREATMENT
• DIFFERENTIAL DIAGNOSIS
Pleomorphic adenoma
Warthins tumour
Parotid lymphnode enlargement
• TREATMENT
Superficial parotidectomy with preservation of the
facial nerve, in parotid gland
Removal of the gland, in submandibular gland
Gland removal with a normal cuff of tissue is the
treatment of choice for oncocytomas of minor
salivary glands

25. BASAL CELL ADENOMA
• It is an uncommon salivary gland tumour,
histopathologically composed of basaloid
(resembling basal cells), epithelial cells arranged in
solid, trabecular, tubular or membranous patterns.
• Hence the name basal cell adenoma
• It arises from the neoplastic transformation of
reserve cells in intercalated ducts and shows
differentiation of both epithelial and myoepithelial
elements

26. CLINICAL FEATURES
• Age- 50 to 70 years
• Gender- female predilection
• Location- 70% in parotid, upper lip (minor salivary
gland)
• Signs and symptoms-
Slow growing, freely movable
Painless
Less than 3cm in diameter

27. CLINICAL APPEARANCE

28. PATHOLOGY
• It is well-encapsulated tumour in major salivary
glands whereas in minor salivary glands, the
capsule will be ill-defined
• Three varieties exist-
1.Solid- islands or sheets of basaloid cells. Normal
sized- nuclei and basophilic with minimal cytoplasm.
2.Trabecular-tubular form- cord of epithelium
3.Membranous form- multilocular and 50% cases are
encapsulated. It grows in clusters interspersed with
normal salivary gland tissue.

31. DIFFERENTIAL DIAGNOSIS AND
TREATMENT
• DIFFERENTIAL DIAGNOSIS
Canalicular adenoma
Sebaceous adenoma
Clear cell adenoma
• TREATMENT
Conservative surgical excision extending to normal
tissue.
Low recurrence rate, except membranous form
maybe.

32. CANALICULAR ADENOMA
• Uncommon neoplasm composed of epithelial cells
arranged in a single or double layer forming
branching cords in a loose stroma
• CLINICAL FEATURES
Age- older than 50 years
Gender- female predilection
Location- 80% cases in the upper lip
Symptoms and signs- slow growing, movable and
asymptomatic. Well-circumscribed and painless.

33. HISTOLOGY
• Long columns or cords of cuboidal columnar cells in
a single layer
• These layers are parallel, form long canals
• Sometimes, row of cells are loosely approximated
and appear as a double row of cells
• The supporting stroma is loose, fibrillar and highly
vascular.
• The cystic spaces are filled with eosinoplhilic
material.

35. MYOEPITHELIOMA
• Uncommon salivary gland tumour (<1%)
• Occurs in the parotid gland and in minor salivary
glands of the palate.
• No gender predilection.
• Average age group affected is in the sixth decade
of life.
• Clinically, it is a well-circumscribed, asymptomatic,
slow-growing mass.

36. PATHOLOGY
• Consists of spindle-shaped, plasmacytoid cells, or a
combination of the two
• Diagnosis is based on identification of myoepithelial
cells and must be differentiated from other benign
and malignant epithelial and mesenchymal
tumours for treatment planning.
• Growth patterns vary from solid to a loose stroma
formation with myoepithelial cells.
• This tumour is epithelial in origin however, it
functionally resembles smooth muscle and is
demonstrated by immunohistochemical staining for
actin cytokeratin and S-100 protein.

39. TREATMENT
• Standard surgical excision, including a border of
normal tissue, is recommended.
• Recurrence is uncommon.

40. SEBACEOUS ADENOMA
• A rare benign tumour derived from sebaceous
glands located within salivary gland tissue
• Parotid gland is most commonly involved
• Age group affected – 22 to 90 years, mean age at
initial clinical presentation is 58 years.
• The tumour is more common in men.
• CLINICAL PRESENTATION
Encapsulated or sharply circumscribed tumour that
varies in color from grayish white to pinkish white to
yellow or yellowish grey.

41. PATHOLOGHY AND TREATMENT
• PATHOLOGY
• These are composed of sebaceous cell nests with
minimal atypia and pleomorphism and no
tendency to invade
• Sebaceous glands vary in size and are usually
embedded in a fibrous stroma.
• TREATMENT
Conservative excision.
No recurrences.

42. DUCTAL PAPILLOMA
• They include three rare benign salivary gland
neoplasms which exhibit papillary projections i.e.
showing surface projections, histologically.
• The unique features of this tumour are-
1.Papillar projections
2.All three tumours arise from the excretory duct
3.Commonly affects the minor salivary gland
• Three benign tumours include-
1.Intraductal papilloma
2.Sialadenoma papilliferum
3.Inverted ductal papilloma

43. SIALADENOMA PAPILLOMA
• CLINICAL FEATURES
Age- 30 to 70 years
Male predilection
Most commonly seen on palate and buccal
mucosa minor glands.
Well-circumscribed, painless, papillary exophytic
growth
• HISTOLOGY
Epithelium lined papillary projections supported by
fibrovascular connective tissue, forming a series of
clefts within the lesion

44. INVERTED DUCTAL PAPILLOMA
• CLINICAL FEATURES
Age- 30 to 60 years.
Male predilection
Buccal mucosa, lower lip and vestibule of lower
jaw.
Asymptomatic, firm, submucosal nodule <1.5cm
Occurs near the orifice of salivary gland ducts.
• HISTOLOGY
• Resembles sialadenoma
• Consists of projections of ductal epithelium that
proliferate to surrounding tissues, forming clefts.

45. TREATMENT
• Surgical excision
• Recurrence is rare.