salivery gland tumors

1. SALIVARY
GLAND
TUMORS
DR.NITISH.S
2nd year PG
Under the guidance of
DR.SHARATH

2. INTRODUCTION
 The salivary glands consist of two parotid glands, two
submandibular glands, two principal sublingual
glands, and a large number of minor salivary glands.

3. EMBRYOLOGY
 The parotid gland is ectodermal in
origin.
 The stroma (capsule and septae) of
the glands originates from
mesenchyme that is mesodermal in
origin.
 PG is also unique because its
epithelial buds grow, branch and
extend around the divisions of the
facial nerve.

4. Histology
The Secretory Unit
 Acinus (serous, mucous,
mixed)
 Myoepithelial cells
 Intercalated duct
 Striated duct
 Excretory duct

5. • Parotid: mostly serous
• Submandibular: mixed,mostly
mucinous
• Sublingual: mixed
• Stroma: Plasma cells

6. PAROTID GLAND
 The parotid gland lies in the space behind
the mandible,below the external ear, in
front of the mastoid process, and extends
forwards on the lateral surface of the
masseter.
 It has 4 surfaces-
superior(base),superficial,anteromedial and
posteromedial.

7.  The gland is divided into deep and superficial lobes, separated
by the facial nerve.
 An accessory lobe is occasionally present lying anterior to the
superficial lobe on the masseter muscle.
 The deep cervical fascia splits to form a capsule to enclose the
gland. The superficial layer is thickened and adherent to the
gland.

8. Relations
 Above—lie the external
auditory meatus and
temporomandibular
joint.
 Below—it overlaps the
posterior belly of
digastric.
 Anteriorly—it overlaps
the mandible and the
overlying masseter.
 Medially — lies the
styloid process.

9. Parotid duct
 The parotid duct (of Stensen) arises from the anterior part of
the gland, runs over the masseter a finger’s breadth below the
zygomatic arch to pierce the buccinator and open opposite
the second upper molar tooth.
 The average dimensions of the parotid duct are 5 cm long and
3 mm wide.

10. Contents
 Facial nerve
 retromandibular vein, formed by
the junction of the superficial
temporal and maxillary veins.
 The external carotid artery, dividing
at the neck of the mandible into its
superficial temporal and maxillary
branches.

11. FACIAL NERVE
 The facial nerve emerges from the stylomastoid foramen, winds laterally to the styloid
process and can then be exposed surgically in the inverted V between the bony part of
the external auditory meatus and the mastoid process.

12. Course and branches

14. VASCULAR SUPPLY

15. INNERVATION
 Preganglionic nerves travel begin in the
inferior salivatory nucleus then travels in
the lesser petrosal branch of the
glossopharyngeal nerve and synapse in
the otic ganglion.
 Postganglionic secretomotor fibres
reach the gland via the
auriculotemporal nerve.
 Sympathetic nerves are vasomotor.

16. Submandibular gland
 The submandibular gland is made up of
a large superficial and a small deep lobe
divided by the mylohyoid.
 The superficial lobe of the gland lies at
the angle of the jaw, wedged between
the mandible and the mylohyoid and
overlapping the digastric muscle.

17.  It has 3 surfaces inferior,lateral and
medial.
 The gland is enclosed between 2
layers of deep cervical fascia.
 Posteriorly it comes into contact
with the parotid gland,separated
only by a condensation of its
fascial sheath (the stylomandibular
ligament).

18. Whartons duct
 The submandibular duct arises from this deep part of the
gland and runs forward, beneath the mucosa of the floor of
the mouth along the side of the tongue, to open immediately
at the side of the frenulum.
 The submandibular duct is thin walled and about 5 cm in
length.

19. Vascular supply and Innervation

20. Sublingual Glands
 The principal sublingual glands are paired and located in the
submucosa, superficial to the mylohyoid muscle.
 Each gland is bounded laterally by the inner cortex of the
mandible and medially by the styloglossus muscle; the paired
glands meet in the midline.
 The sublingual glands have multiple small ducts, referred to as the
ducts of Rivinus, which open directly into the oral cavity. Some of
these ducts unite to form the major ducts of Bartholin.

21. Functions of saliva
 Moistens oral mucosa
 Moistens & cools food
 Medium for dissolved food
 Buffer (HCO3)
 Digestion (Amylase, Lipase)
 Antibacterial (Lysozyme, IgA, Peroxidase)
 Mineralization

22. Classification of salivary gland tumours
Type Subgroup Common examples
(1)Adenoma Pleomorphic
Monomorphic
Pleomorphic adenoma
Adenolymphoma (Warthin’s tumour)
(II) Carcinoma Low grade
High grade
Acinic cell carcinoma
Adenoid cystic carcinoma
Low-grade mucoepidermoid carcinoma
(III)Non-epithelial tumours Haemangioma, lymphangioma
(IV) Lymphomas Primary lymphomas
Secondary lymphomas
Non-Hodgkin’s lymphomas
Lymphomas in Sjögren’s syndrome
(V) Secondary tumours Tumours of the head and neck
especially
Skin and bronchus
(VI) Unclassified tumours Local
Distant
(VII) Tumour-like lesions Solid lesions
Cystic lesions
Benign lymphoepithelial lesion
Adenomatoid hyperplasia
Salivary gland cysts

23. Salivary gland tumours – frequency
and distribution
Type Location Frequency Malignant (%)
Major Parotid
Submandibular
Sublingual
Common
Uncommon
Very rare
10–20
50
85
Minor Upper aerodigestive
tract
Rare 90

24. Benign Neoplastic Diseases:
Introduction
 64–80% percent of primary salivary tumors occur in the
salivary gland, 7–15% occur in the submandibular gland, and
< 1% occur in the sublingual glands.
 54–80% of all tumors are benign.
 Peak incidence of salivary tumors occurs in the sixth to
seventh decades.

25. Pleomorphic Adenomas
 Pleomorphic adenomas, or benign mixed tumors, are the most
common neoplasms of the salivary glands.
 They represent approximately 60–70% of all parotid tumors
and 90% of submandibular benign tumors.
 These neoplasms affect females more than males and are
commonly seen in the third to sixth decades of life.
 There are no known etiologic factors.

26.  When disease occurs in parotid, commonly it involves superficial lobe or
superficial and deep lobe together.
 But sometimes only deep lobe is involved where it presents as swelling
in the lateral wall of the pharynx.It is called as dumb bell tumour.

27.  Histologically it shows:
- Epithelial cells
- Myoepithelial cells
- Mucoid material with myxomatous
changes
- Cartilages/pseudocartilages

28. Clinical Features of parotid tumour
 Present as a single painless, smooth, firm lobulated,mobile
swelling
 Raised ear lobule
 Cannot be moved above the zygomatic bone—curtain sign
 Deviation of uvula and pharyngeal wall towards midline in
case of deep lobe tumour.
 Obliteration of retromandibular groove is common.

29. Investigations
 FNAC is very important and diagnostic.
 The accuracy rate is approximately 85% in determining if a
tumor is benign or malignant; this rate is higher when
determining whether or not a lesion originates from parotid
tissue
 CT/MRI scan to know the status of deep lobe, local extension
and spread.

30. Treatment
 Surgery:First line treatment.
 If only superficial lobe is involved, then superficial
parotidectomy is done.
 If both lobes are involved, then total conservative
parotidectomy is done by retaining facial nerve.

31. Complications
 Recurrence—5-50%.
 Malignancy.
 3-5% in early tumours.
 10% in long duration tumours ( >15 years) .

32. ADENOLYMPHOMA (Warthin’s
Tumour)
 It is a benign tumour that occurs only in parotid,usually in the
lower pole.
 It is said to be due to trapping of jugular lymph sacs in
parotid during developmental period.
 It composed of double layer of columnar epithelium, with
papillary projections into cystic spaces with lymphoid tissues
in the stroma.
 It usually involves only superficial lobe of parotid gland. It
may also be multicentric.

33. Features
 It presents as a slow growing, smooth, soft, cystic,fluctuant
swelling, in the lower pole, often bilateral and is nontender.
 It is common in males – 4:1.
 Common in old people – >60 years.
 Its incidence is 10%.
 It is bilateral – 10%.
Treatment
 Superficial parotidectomy.

34. Monomorphic Adenomas
 These slow-growing tumors represent less than 5% of all
salivary gland tumors.
 Monomorphic adenomas differ from pleomorphic adenomas,
in that they consist of only one morphologic cell type.
 Monomorphic adenomas are subclassified that include;
-basal cell adenomas
-canalicular adenomas
-oncocytomas or oxyphilic adenoma
-Myoepitheliomas.

35. Basal Cell Adenomas
 Basal cell adenomas account for 2% of all epithelial salivary gland
neoplasms.
 Histologic types include tubular, trabecular, cylindroma, and solid; the
latter is the most common variant.
 Basal cell adenomas occur equally between males and females and usually
between the fourth and ninth decades of life.
 The parotid gland is the most common site involved.

36. Canalicular Adenomas
 The canalicular adenoma is a benign neoplasm that affects the
minor salivary glands.
 It must also be differentiated from adenocarcinoma.
 Canalicular adenoma tends to be multifocal and often occurs
in the upper lip mucosa, especially in the elderly.
 Complete intraoral excision is curative, although the
multifocality of the disease can predispose to recurrence if all
foci are not excised.

37. Oncocytomas
 These benign tumors are composed of large polyhedron-
shaped epithelial cells, known as oncocytes, packed with
granular eosinophilic cytoplasm and mitochondria.
 Oncocytomas account for < 1% of all salivary gland
neoplasms. There is no gender predilection and they occur in
the sixth to eighth decades of life.
 Oncocytomas may result from a hyperplastic
process,metaplastic process, or both.
 The parotid gland is the most common site of an oncocytoma,
followed by the submandibular gland.

38.  It presents as a painless, slow-growing mass that is often solid
and occasionally cystic.
 Surgical excision with uninvolved margins is the
recommended treatment; oncocytomas are radioresistant.

39. Myoepitheliomas
 This subtype of monomorphic adenomas accounts for less
than 1% of all salivary gland neoplasms.
 It consists almost exclusively of myoepithelial cells.
 There is no gender predilection and myoepitheliomas are
commonly seen in the third to sixth decades of life.
 The tumor occurs in the parotid gland 40% of the time.
 Histologically, myoepitheliomas are well encapsulated. There
are spindle cell and plasmacytoid cell types.

40. Granular Cell Tumors
 The granular cell tumor is benign with malignant potential and
is most commonly associated with the minor salivary glands.
 This tumor tends to occur in the oral cavity and is well
circumscribed, mobile, and painless.
 Fine-needle aspiration can demonstrate a neoplastic process.
 Because of its malignant potential, a combination of wide
local excision and close observation is the most effective
treatment.

41. Hemangiomas
 These benign tumors are of endothelial cell origin and
represent less than 5% of all salivary gland tumors.
 In children, the capillary hemangioma is the most common
salivary gland tumor, accounting for more than 90% of parotid
gland tumors in children less than 1 year of age.
 It affects females more than males.

42.  Clinical Features
 A hemangioma usually presents at birth as a unilateral, painless mass. It has a
rapid, proliferative growth that often causes cosmetic deformity.
 Treatment
 There is a possibility of spontaneous regression.
 If there is significant cosmetic or functional compromise, complete excision
via parotidectomy with facial nerve preservation may be indicated.

43. Signs of malignant transformation
 Recent increase in size
 Pain and nodularity
 Involvement of skin, ulceration
 Involvement of masseter
 Involvement of facial nerve—Lower facial nerve palsy
(Difficulty in closing eyelid, difficulty in blowing and clenching
teeth)
 Involvement of neck lymph node

44. Malignant Neoplastic Diseases:
Introduction
 Malignant salivary gland neoplasms represent 3–4% of head
and neck malignancies.
 Unlike the more common mucosal head and neck cancers,
which attribute to excessive tobacco and alcohol use, specific
carcinogenic factors for malignant salivary gland growths have
not been as clearly identified.
 Viral infections, radiation, environmental exposure, and
genetic factors have been hypothesized as causes.

45. Pathogenesis
 The Reserve Cell Theory (currently favored) of salivary gland neoplasia
states that salivary neoplasms arise from reserve or stem cells of the salivary
duct system.
 The type of neoplasm depends on the stage of differentiation of the reserve
cell at the time at which the neoplastic transformation occurs.
 The intercalated duct reserve cells give rise to adenoid cystic and acinic cell
carcinoma.
 The excretory duct reserve cells give rise to mucoepidermoid, squamous
cell, and salivary duct carcinoma.

46.  The Multicellular Theory of salivary gland neoplasia states that salivary
neoplasms arise from differentiated cells along the salivary gland unit.
 For example, squamous cell carcinoma arises from the excretory duct
epithelium and acinic cell carcinoma arises from the acinar cells.

47. Mucoepidermoid Carcinoma
 It is the most common type of malignant salivary gland
disorder.
 Eighty to ninety percent of mucoepidermoid carcinoma occurs
in the parotid gland.
 Its prevalence is highest in the fifth decade of life, with a
female preponderance as high as 4:1.

48.  Mucoepidermoid carcinomas are classified as;
 low grade(mucus cells mainly)
 intermediate,and
 high grade(epidermoid cells mainly)
 Clinical aggressiveness, local invasion, and lymph node
metastases are all greater and the prognosis is worst for high-
grade tumors.
 The 5-year survival rate for low-grade mucoepidermoid
carcinomas is 70%, whereas for high grade it is only 47%.

49. Clinical Features
 Swelling in the parotid or submandibular region, slowly
increasing in size.
 It is hard, nodular and often presents with involvement of
skin and lymph nodes.
 Facial nerve involvement is late in mucoepidermoid
carcinoma of parotid.
 Treatment-Radical surgery of the gland is the treatment of
choice.

50. ADENOID CYSTIC CARCINOMA
 It is the most common type of malignant disorder to arise in the submandibular, the
sublingual, and the minor salivary glands.
 There are 3 histological types;
-cribriform subtype (44%)
-tubular subtype (35%)
-solid subtype (21%)
It arises from myoepithelial cells and duct epithelial cells with cribriform or lace like
appearance.

51.  Perineural spread, including "skip lesions" occurs commonly (up to 80% of
cases).
 It also invades periosteum and bone medulla early and spreads
extensively.
 Prognosis is poor.
 Radical resection of the involved gland and radical radiotherapy is the
treatment of choice.

52. Adenocarcinoma
 Adenocarcinomas of the major salivary glands originate from
excretory or striated ducts.
 Patterns of growth include tubular, papillary, glandular, and
solid.
 Women are affected more often than men.
 Common in the sixth decade.
 Around 20% present with lymph node metastases.
 Radical surgery of the gland is the treatment of choice.

53. Lymphoma
 Salivary gland lymphoma arises from intraglandular lymph
nodes or from extranodal lymphoid tissue within the salivary
glands.
 Patients are typically in their sixth or seventh decade. Ninety
percent occur in the parotid gland.
 The majority of salivary gland lymphomas are of B-cell
lineage.
 When it is confined to parotid gland total parotidectomy with
radiotherapy and later chemotherapy is the treatment.

54. Metastases to the Salivary Glands
 Less than 10% of malignant salivary gland disorders are
metastases from other sites.
 Most are lymphatic metastases to the parotid gland from skin
cancers of the face, ear, or scalp.
 Almost always they are inoperable as it presents in the
advanced stage of the disease.

55. Investigations
 FNAC
 CT/MRI scan to know the status of deep lobe, local extension and spread.

56. TNM Staging of Malignant Salivary Tumours
T—Tumour
Tx --Tumour cannot be assessed.
T0 --No evidence of primary
tumour.
T1 --Tumour < 2cm without
extraparenchymal spread.
T2 --Tumour 2-4 cm.
T3 --Tumour 4-6 cm.
--or with extraparenchymal
--but no facial nerve spread.
T4 --Tumour > 6 cm.
--or spread to facial nerve, skin,
mandible, ear canal
--T4a.
--or spread to base of skull,
pterygoid plates,
encased external carotid artery –
T4b.
N—Lymph node
Nx —Nodes not assessed.
N0 —Regional nodes not
N1 —Single ipsilateral node < 3
cm.
N2a —Single ipsilateral node 3-6
cm.
N2b —Multiple ipsilateral nodes
6 cm.
N2c —Bilateral or contralateral
nodes < 6 cm.
N3 —Single node spread > 6 cm.
M—Metastases
M0 —No blood spread.
M1 —Blood spread present.

57. Parotidectomy
 Incision and development of a skin
flap
 The most commonly used incision is
the ‘lazy S’ pre-auricular– mastoid–
cervical.
 The skin flap is developed forwards to
the anterior border of the gland.
 Posterior undermining of the incision
in the cervical region facilitates access
to the anterior border of the
sternomastoid muscle.

58. Mobilisation of the gland
 An avascular plane is developed, which
requires elective transection of the
great auricular nerve.
 A second avascular plane is developed
along the anterior border of the
cartilaginous and bony external
auditory meatus immediately anterior
to the tragus.
 The two avascular planes are then
connected.

59.  Location of the facial nerve trunk
 Dissection of the gland off the facial
nerve
 The divisions and branches of the
facial nerve are followed to the
periphery in a sequential manner,
usually beginning with the upper
division.
 Wound closure is done in layers after
drain placement.

60. Radical parotidectomy
 Radical parotidectomy involves removal of all parotid
gland tissue and elective sectioning of the facial nerve, usually
through the main trunk.
 The ipsilateral masseter muscle is also removed and may also
require simultaneous neck dissection, particularly where there
is lymph node metastases in the ipsilateral neck.

61. Complications of parotid gland
surgery
• haematoma formation
• infection
• temporary facial nerve weakness
• transection of the facial nerve and permanent facial weakness
• sialocoele
• facial numbness
• permanent numbness of the ear lobe associated with great
auricular nerve transection
• Frey’s syndrome.

62. FREY’S SYNDROME
 Occurs in 10% of cases.
 It is due to injury to the auriculo temporal nerve, wherein post-
ganglionic parasympathetic fibres from the otic ganglion become united
to sympathetic nerves from the superior cervical ganglion.
 Flushing, sweating, pain and hyperaesthesia in the skin over the face
innervated by the auriculotemporal nerve, whenever salivation is
stimulated.

63. Managements
 Antiperspirants, usually containing aluminium chloride.
 Denervation by tympanic neurectomy.
 Injection of botulinum toxin into the affected skin.

64. Prevention
 sternomastoid muscle flap;
 temporalis fascial flap;
 insertion of artificial membranes between the skin and the
parotid bed.
 All these methods place a barrier between the skin and the
parotid bed to minimise inappropriate regeneration of
autonomic nerve fibres.

65. Submandibular gland excision
 Incision and exposure of gland:
 The incision should be marked at least 3–4 cm
below the lower border of the mandible to avoid
damage to the marginal mandibular branch of the
facial nerve.
 Posteriorly, the incision approaches the angular
tract where the deep cervical fascia splits to form
the investing layer around the sternomastoid
muscle.
 Superficial veins, including the anterior facial vein,
require ligation.

66. Gland mobilisation
 The superficial lobe of the submandibular gland is
first mobilized.
 As dissection proceeds, the posterior belly and
anterior belly of the digastric muscle are identified
and dissected.
 Dissection posteriorly identifies the facial artery
which is divided to facilitate further mobilisation.

67. Dissection of the deep lobe and
identification of the lingual nerve
 An important landmark in submandibular
gland dissection is the posterior border of the
mylohyoid muscle.
 The deep lobe is retracted inferiorly to reveal
the lingual nerve.
 The gland is then pedicled entirely on the
submandibular duct, and ligated.
 Wound closure is done in layers after drain
placement.

68. Complications of submandibular gland
excision
• haematoma
• wound infection
• marginal mandibular nerve injury
• lingual nerve injury
• hypoglossal nerve injury
• transection of the nerve to the mylohyoid muscle producing submental skin
anaesthesia.

69. Indications for Neck Dissection
 Clinically apparent cervical adenopathy (14% of cases)
 Tumors > 4 cm (in which the risk of occult metastases is >
20%)
 High-grade histology (in which the risk of occult metastases is
> 40%)

70. Radical neck dissection
 It is resection of lymph nodes (level I to V), fat, fascia,sternomastoid muscle,
omohyoid muscle, internal jugular vein, external jugular vein, accessory nerve,
submandibular salivary gland, lower part of parotid,prevertebral fascia.
 Modified radical neck dissection
 Only spinal accessory nerve is preserved —MRND type I.
 Accessory nerve and sternocleidomastoid are preserved—-MRND type II.
 Accessory nerve, sternomastoid and internal jugular veins are preserved—
MRND type III.

71. Complications of block dissection
 Haemorrhage
 Infection
 Lymph ooze
 Carotid blow out
 Seroma and flap necrosis
 Frozen shoulder is common
 Rarely pneumothorax and chylous fistula
 Drooping of shoulder due to paralysis of trapezius.

72. Chemotherpy
 The role for chemotherapy in the treatment of malignant
salivary gland disorders is limited to the palliative setting, such
as in advanced-stage or metastatic disease not amenable to
local therapies including surgery and/or radiation.
 Currently, paclitaxel is the agent used most frequently.
 The integration of radiation and chemotherapy has been
shown to increase local control.

73. Indications for radiotherapy in
malignant salivary gland tumours
 All adenoid cystic and adenocarcinomas
 T3 and T4 tumours
 Recurrent tumours
 Poorly differentiated tumours
 Tumours with lymph node involvement
 As preoperative radiotherapy
 Recurrent benign pleomorphic adenomas
 Spillage during surgery in case of pleomorphic adenomas
 Residual tumours, refractory tumour or nerve involvement
 When clearance margin is inadequate

74. References
 Bailey & Love's Short Practice of Surgery-26TH EDITION.
 Devita, Hellman & Rosenberg's Cancer: Principles & Practice of Oncology,
8th Edition.
 Otolaryngology Head & Neck Surgery, 2nd Edition.
 Mastery of surgery 5th edition.
 Schwartz’s Principles of Surgery 10th edition.

75. THANK YOU