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Toronto Notes 2019
Neck Masses
Otolaryngology OT31
• malignant(seeTable15,OT31andTable16,OT35) • benign
■ benign mixed (pleomorphic adenoma): 80%
■ Warthin’s tumour (5-10% bilateral, M>F): 10% ■ cysts, lymph nodes, and adenomas: 10%
■ oncocytoma: <1%
Epidemiology
• 3-6%ofallheadandneckneoplasmsinadults • meanageatpresentation:55-65
• M=F
Parotid Gland Neoplasms
Clinical Features
• 80%benign(mostcommon:pleomorphicadenoma),20%malignant(mostcommon:mucoepidermoid) • ifbilateral,suggestsbenignprocess(Warthin’stumour,Sjögren’s,bulimia,mumps)orpossiblelymphoma • facial nerve involvement (i.e. facial paralysis) increases risk of malignancy
Investigations
• FNAbiopsy
• CT,U/S,orMRItodetermineextentoftumour
Treatment
• treatmentofchoiceissurgeryforallsalivaryglandneoplasms–benignandmalignant
• pleomorphic adenomas are excised due to risk of malignant transformation (5% risk over prolonged
period of time)
• superficialtumour
■ superficial parotidectomy above plane of CN VII ± radiation
■ incisional biopsy contraindicated
• deeplesion
■ near-total parotidectomy sparing as much of CN VII as possible
■ if CN VII involved, then it is removed and cable grafted
• complications of parotid surgery
■ hematoma, infection, salivary fistula, temporary facial paresis, Frey’s syndrome (gustatory sweating)
Prognosis
• benign:excellent,<5%ofpleomorphicadenomasrecurs
• malignant:dependentonstageandtypeofmalignancy(seeTable16,OT35)
Neck Masses
Approach to a Neck Mass
• ensurethattheneckmassisnotanormalneckstructure(hyoid,transverseprocessofC1vertebra, prominent carotid bulb)
• anyneckmasspersistingfor>2wkshouldbeinvestigatedforpossibleneoplasticcauses
A mass sitting above an imaginary line drawn between the mastoid process and angle of the mandible is a parotid neoplasm until proven otherwise
DDx Parotid Tumour
Benign
• Pleomorphic adenoma
• Warthin’s tumour (more common in men)
• Benign lymphoepithelial cysts (viral
eitiology e.g. HIV) • Oncocytoma
Malignant
• Mucoepidermoid carcinoma • Adenoid cystic carcinoma • Acinic cell carcinoma
Frey’s syndrome is a post-operative complication characterized by gustatory sweating. It is due to aberrant innervation of cutaneous sweat glands by parasympathetic nerve fibres that are divided during surgery
Table 15. Prevalence of Acquired Causes of Neck Lumps According to Age
Age (yr)
<40 >40
Possible Causes of Neck Lump
1. Inflammatory 2. Congenital/Developmental 1. Neoplastic 2. Inflammatory
3. Neoplastic 3. Congenital
Differential Diagnosis
• congenital
■ lateral (branchial cleft cyst, laryngocele, plunging ranula, lymphatic/venous/venolymphatic
malformation)
■ midline (thyroglossal duct cyst, dermoid cyst, teratoma, thyroid/thymus anomaly, vascular
malformation)
• infectious/inflammatory
■ reactive lymphadenopathy (2° to tonsillitis, pharyngitis)
■ infectious mononucleosis
■ Kawasaki, Kikuchi-Fujimoto, Kimura, Cat-scratch disease, Castleman, Rosai-Dorfman disease ■ HIV
■ sialolithiasis, sialadenitis
■ thyroiditis