2. INTRODUCTION
• less then 1% of Head and neck neoplasms
• 70-80% are benign
• Radiological imaging very important for diagnosis
• Surgical excision is the primary treatment
• Morbidity of surgery should be considered along with natural history of disease in making a
treatment plan
14. Salivary Gland Tumors
• Most common PPS neoplasms: 40-50%
• Pleomorphic adenoma 80-90%
• Mucoepidermoid most common malignant
• Less than 5% parotid tumors involve the PPS
15. Salivary Gland Tumors
• Located in prestyloid space
• From deep lobe of parotid or minor salivary glands
• On CT or MRI a fat plane between the parotid and a prestyloid mass indicates minor salivary
gland origin
• Displace the internal carotid posteriorly
17. Schwannoma
• Most common neurogenic neoplasm
• Vagus, sympathetic chain most common
• Benign and slow growing
• Generally don’t affect nerve of origin
• Less than 1% malignant
• Displace internal carotid anteriorly
18. Paraganglioma
Second most common
Highly vascular
Arise from vagus , carotid body, jugular bulb
• Bilateral 10%, familial 30%
• Part of MEN IIA or IIB (medullary thyroid carcinoma,
pheochromocytoma, parathyroid hyperplasia-with or
without mucosal neuromas)
19. • Secrete catecholamines 1-3%
• Malignant 3-10%
• Classically, paragangliomas mobile anterior-posterior but not up and down
• Glomus vagale displace carotid anteriorly
• Carotid body tumors splay internal and external carotid – “lyre” sign
20. Neurofibromas
• 3rd most common neurogenic tumor
• From Schwann cells and fibroblasts
• Unencapsulated (involve nerve)
• Multiple
• Part of Neurofibromatosis type I
23. Evaluation
Detailed history
Complete head and neck examination
Pulse and blood pressure
Cranial nerves
Bimanual palpation
Bruit, thrill
IDL
Neither AJCC nor International union
against cancer have given any staging for
pps tumor
24. Investigations
FNAC
Ultrasound guided
CT-guided FNAC procedures are essential for lesions that are not directly detectable without
imaging techniques
25. Special investigations
24-hour urine collection for catecholamines
Vanillylmandelic acid (VMA)
Metaiodobenzylguanidine scan (MIBG)
27. CT
Locates tumor to prestyloid vs postyloid
Fat plan between mass and parotid
Displacement of carotid artery
Enhancement of lesion
Bone erosion
Limited soft tissue detail -MRI
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33. MRI
Most useful study
Relationship of mass and other soft tissue and carotid more easily seen than with CT
Characteristic appearance of tumor types on MRI allows preoperative Dx 90-95% of patients
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38. Angiography
Used to all enhancing lesions
Gold standard for relation ship to blood vessels
Differentiate neurogenic and vascular
Main indication is planning for surgical treatment
Balloon occlusion test
41. Surgical Rx
Preoperative workup
Pre.op. counselling
Preoperative embolization of tumors > 3cm size with obvious feeding vessel
Functioning paragangliomas should be identified and pre op alpha and beta blockers should be
given
42. Surgical approaches
Depends on location. Size , suspicion of malignancy ,relationship to neurovascular
structures, surgeon experience
Goal is to achieve optimal exposure and vascular control without significant
morbidity
44. Transoral
Has been used for small, benign , prestyloid tumor
Very limited exposure
Increased risk of tumor rupture and spillage,
Risk of injury to neurovascular structure
Not recommended
45. Transcervical
Reserved for pre and post styloid tumors
Transverse incision at level of hyoid
Submandibular gland displaced or removed
Digastric muscle retracted or its tendon is divided
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51. Transparotid
For small deep lobe parotid tumors
Superficial parotidectomy
Division of stylomandibular ligament
Dissect around mandible
May use mandibulotomy
52. Transcervical-parotid
Deep-lobe parotid tumors with PPS extension
Extend cervical incision up infront of ear
identification facial nerve
Divide posterior belly digastric
Divide stylomandibular ligament, styloglossus, stylohyoid
close to styloid process
53. Transmandibular Approaches
Both the lateral mandibulotomy and the median mandibul-
otomy-transpharyngeal approach
Very large tumors
Malignancy
Vascular tumors extending to skull base
Need a tracheostomy
54. infratemporal fossa approach
Preauricular lateral infratemporal fossa approach
Skull base or infratemporal fossa involvement
55. Transcervical-transmastoid
Cervical incision carried postauricularly
Mastoidectomy
Remove mastoid tip exposing jugular fossa
Facial nerve may need to be dissected from Fallopian canal
56. Nonsurgical Management
Poor surgical candidates, failed balloon occlusion, elderly, unresectable lesions,
would require sacrifice of multiple cranial nerves
• Observation for stable tumor
• Radiation for growing tumor
57. Observation
Benign and asymptomatic
Paragangliomas grow 1 -1.5 mm per year
Mortality less than 10% per year for untreated
58. Radiation
Not used for cure
Arrest the growth
Metastatic tumor
Postoperative irradiation is recommended for high-grade malignancies or when wide surgical margins cannot
be obtained.