Resident Conference

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Resident Conference

• February 24, 2005
• Hau Sin Wong

2
History

• 43 year old male complaining of left jaw mass
  which he found incidentally when shaving
• Painless
• Present for 1 month
• No change in size
• No dysphagia, odynophagia, fever, night sweats,
  or weight loss

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History

• PMH HTN, skin cancer on the left temple
• PSH excision of the skin cancer
• Medication atenolol
• All NKDA
• SH h/o smoking 1ppd x20 yrs but quit 8yr ago, no
  excessive alcohol

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Physicial Exam

• Ears tympanic membrane intact and normal
• Nose no intranasal lesions
• OC/OP FOM and BOT soft, no intra-oral lesion,
  Stensons Duct with clear saliva
• Neck 2.5 cm soft mass in the left angle of the
  mandible, no other LAD palpable
• Face left temple skin scar, CNVII all branches
  intact

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Differential Diagnosis

• Vascular-Hemangioma, Artero-venous malformation
• Iatrogenic- seroma, hematoma
• Traumatic-A-V malformation, hematoma
• Autoimmune-Sjogrens
• Metabolic-sialolithiasis, bulemia
• Infectious/inflammatory-Sialadenitis, parotid
  abscess, viral parotitis, granulomatous
  sialadenitis, actinomycosis, benign
  lymphoepithelial lesion, HIV
• Neoplastic- pleomorphic adenoma, monomorphic
  adenoma, Warthins, oncocytoma, oncocytic CA,
  adenoid cystic, acinic cell CA, SCCA,
  mucoepidermoid, Carcinoma ex-pleomorphic adenoma
• Congenital-1st branchial cleft cyst
• Degenerative-

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Diagnostic Studies

• FNA
• Imaging- CT, MRI

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Treatment

• Surgical excision-
• superficial parotidectomy mainly for benign
  lesions
• total parotidectomy mainly for malignant
  lesions, /- nerve resection
• neck dissection for presence of neck nodes

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Embryology Anatomy

• Major Salivary Glands are ectodermal in origin
• Parotid Gland is the 1st to invaginate from the
  stomodeal placode and the last to encapsulate and
  thus has lymph nodes within its tissue
• Theories on the origin of various parotid
  tumors-Bicelluar theory and Multicellular theory

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Bicellular Theory
Excretory Ducts Squamous cell Mucoepidermoid
Intercalated Ducts Pleomorphic adenoma Warthins
tumor Oncocytoma Acinic cell Adenoid cystic
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Multicellular Theory
Striated ductoncocytic tumors Acinar
cellsacinic cell carcinoma Excretory
Ductsquamous cell and mucoepidermoid
carcinoma Intercalated duct and myoepithelial
cellspleomorphic tumors
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Epidemiology

• Distribution
• Parotid 80 overall 80 benign 20 malignant
• Submandibular 15 overall 60 benign 40
  malignant
• Sublingual/Minor 5 overall 40 benign 60
  malignant

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Distribution

• Adult Salivary Tumors
• Benign
• Pleomorphic adenoma
• Warthins tumor
• Monomorphic adenoma
• Oncocytoma
• Malignant
• Mucoepidermoid CA (2 in submandibular gland)
• Acinic Cell CA (1 in submandibular gland)
• Adenocarcinoma
• Adenoid cystic
• SCCA
• Carcinoma ex-pleomorphic adenoma

• Pediatric salivary tumors
• 65 Benign
• Pleomorphic adenoma (48)
• Hemangioma (31)
• Neurofibroma (6)
• 35 Malignant
• Mucoepidermoid CA (37)
• Acinic Cell CA (22)
• Rhabdomysarcoma (9)
• Lymphoma (9)

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Risk Factors

• Radiation higher risk for mucoepidermoid CA and
  pleomorphic adenoma
• Smoker- higher risk for Warthins
• Wood working/Asbestos/rubber/boot shoe
  manufacturer- risk for Adenocarcinoma

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Pleomorphic Adenoma

• Painless
• 4-6th decades of life
• Smooth surface, well demarcated gross appearance
• Composed of multiple epithelial, stromal, and
  myoepithelial components
• Tx superficial parotidectomy, DO NOT enucleate
  b/c pseudocapsule risks recurrence

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Warthins Tumor

• A.K.A. papillary cystadenoma lymphomatosum
• Slow growing and painless
• 10 bilateral and multicentric
• Smooth encapsulated with solid and cystic
  components on gross appearance
• Papillary projections into cystic spaces
  surrounded by lymphoid stroma
• Tx superficial parotidectomy

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Oncocytoma

• 6th decade of life
• Painless, 10 bilateral
• Polyhedral cells, plump and uniform w/ high of
  mitochondria on electron microscopy
• Tx superficial parotidectomy

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Mucoepidermoid Carcinoma

• Most Common Malignant Neoplasm
• 3 Grades low, intermediate, high-grade based on
  degree of mucoid and epithelial components (i.e.
  higher epithelial component the higher the grade
  and the poorer the prognosis)
• 3rd to 8th decade with peak at 5th decade
• 30-40 Metastasis rate
• Tx total parotidectomy with post-op XRT /- neck
  dissection for presence of neck nodes

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Adenoid Cystic Carcinoma

• Second most common malignancy
• 5th decade
• Painful, involvment of the facial nerve
• Mainly in submandibular gland
• Solid gross appearance w/ swiss cheese
  histologic appearance
• Tx total parotidectomy w/ post-op XRT, possible
  sacrifice of CN VII

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Acinic Cell Carcinoma

• 2nd most common parotid and pediatric malignancy
• 5th decade
• FgtM
• Bilateral parotid disease in 3
• Presentation
• Solitary, slow-growing, often painless mass
• Tx superficial or total parotidectomy

• Histology
• Solid and microcystic patterns
• Most common
• Solid sheets
• Numerous small cysts

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Adenocarcinoma

• Rare
• 5th to 8th decades
• F gt M
• Parotid and minor
• salivary glands
• Presentation
• Enlarging mass
• 25 with pain or facial weakness
• Histology
• Heterogeneity
• Presence of glandular structures and absence of
  epidermoid component

• Tx
• Total Parotidectomy
• Neck dissection
• Postoperative XRT

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Carcinoma Ex-pleomorphic Adenoma

• Commonly with h/o long standing parotid mass,
  suddenly enlarging
• Total Parotidectomy and post-op XRT

22
Squamous Cell Carcinoma

• 1.6 of salivary gland neoplasms
• 7th-8th decades
• MF 21
• MUST RULE OUT
• High-grade mucoepidermoid carcinoma
• Metastatic SCCA to intraglandular nodes
• Direct extension of SCCA
• Tx total parotid /-neck dissection post-op XRT

Histology Infiltrating nests of tumor cells
(Well differentiated keratinizing,
Moderately-well differentiated, poorly
differentiated no keratinization
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Conclusion

• Extent of surgery is dictated by the tumor size
  and the degree of local extension
• Facial nerve is preserved in all cases unless
  directly involved with tumor
• In general, N necks undergo neck dissection
• Post-op irradiation is given in all cases except
  for small, low-grade tumors

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Complications

• Freys Syndrome Gustatory Sweating (50-100
  occurrence)
• parasympathetic nerve fibers innervating
  salivary gland now innervates sweat glands and
  blood vessels (both sympathetic and
  parasympathetic nerves use Ach as the
  neurotransmitter)
• minor starch-iodine test
• Tx antiperspirant, 3 scopolamine cream,
  section Jacobsons nerve, allograft btw parotid
  and skin
• Facial Nerve injury 5 incidence
• Sialocele Tx w/ aspiration and pressure dressing
  
• Hematoma

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Facial Nerve Anatomy

• Meatal brainstem to IAC
• Labrynthine IAC to 1st Genu at Geniculate
  Ganglion, GSPN and fallopian canal place risk of
  injury of nerve greatest in T-bone injury
• Tympanic 1st Genu to 2nd Genu near lateral SCC,
  15 dehiscence
• Mastoid Vertical segment from lateral SCC to
  stylomastoid foramen
• Extratemporal Stylomastoid foramen to facial
  musculature, 5 divisions (temporal, zygomatic,
  buccal, mandibular, cervical)

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Superficial Landmarks of the Facial Nerve

• Temporal Branch Within the vector 1cm anterior
  to the tragus to the lateral eyebrow
• Buccal Branch Within the vector of the tragus to
  the lateral oral commisure
• Mandibular Branch 4cm diameter around the facial
  notch at the mandible

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Nerve Anatomy

• Axons are basic unit surrounded by endoneurium
• Bundles of Axons form fasicles which are
  surrounded by perineurium
• Bundles of Fasicles are surrounded by epineurium

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Nerve injury classification
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Degeneration and Regeneration efforts in

• Cell Body initially a decrease in
  neurotransmitter synthesis then at 3wks increase
  protein synthesis for regeneration
• Proximal Nerve presence of minimal axonal flow,
  regeneration at 3wks when cell body completes
  protein synthesis
• Distal Nerve Wallerian degeneration in 2nd to
  5th degree injury after 72hrs with dissolution of
  myelin and axoplasm toward the motor end-plate
• Muscle Decrease in fiber size, but
  myoarchitecture remains, EMG necessary to
  determine if muscle still capableof reinnervation
  (fibrillation or polyphasic potentials)

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Surgical Repair

• Neurorhaphy- primary anastimosis of nerve at
  epineurium or perineurium
• Re-routing mastoid-meatal re-routing will
  provide 1cm length to decrease tension at the
  anastomosis
• Nerve Crossover hypoglossal to facial nerve
• Interposition graft likely necessary for gaps
  gt1-2cm
• Donors greater auricular nerve, sural nerve
  (35cm avail), ansa hypoglossi, lateral femoral
  cutaneous