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Toronto Notes 2019
Neoplasms of the Head and Neck
Otolaryngology OT37
Thyroid Carcinoma
Table 18. Bethesda Classification of Thyroid Cytology
Category
Non-diagnostic or unsatisfactory Benign
Follicular lesion of undetermined significance/ Atypia of undetermined significance
Follicular/Hürthle cell neoplasms Suspicious for malignancy Malignant
Table 19. Thyroid Carcinoma
Risk of Malignancy
Unknown 0-3% 5-15%
15-30% 60-75% 97-99%
Incidence (% of all thyroid cancers)
Route of Spread Histology
Other
Prognosis
Treatment
Papillary
70-80%
Lymphatic
Orphan Annie nuclei Psammoma bodies Papillary architecture
Ps – Papillary cancer Popular (most common) Palpable lymph nodes Positive I131 uptake Positive prognosis Post-operative I131 scan to guide treatments
98% at 10 yr
Small tumours: Near total thyroidectomy or lobectomy Diffuse/bilateral: Total thyroidectomy
± neck dissection ± post- operative I131 treatment
Follicular
10-15%
Medullary
1 to 2%
(90% sporadic, 10% familial – test for RET germline mutation)
Lymphatic and hematogenous
Amyloid
May secrete calcitonin, prostaglandins, ACTH, serotonin, kallikrein, or bradykinin
Ms – Medullary cancer Multiple endocrine neoplasia (MEN IIa or IIb) aMyloid
Median node dissection
50% at 10 yr
20% at 10 yr if detected when clinically palpable
Total thyroidectomy Median and/or lateral compartment node neck dissection (based on serum calcitonin)
Modified neck dissection Post-operative thyroxine, radiotherapy Tracheostomy
Screen relatives
Anaplastic
<2%
N/A
Giant cells Spindle cells
More common in elderly 70% in women
20-30% have Hx of differentiated thyroid Ca (mostly papillary) or nodular goitre mass
Rapidly enlarging neck Rule out lymphoma
20-35% at 1 yr 13% at 10 yr
Subtotal thryoidectomy, radiation, chemotherapy, palliative care
Small tumours:
Total thyroidectomy ± external beam
Lymphoma
<1%
Usually non-Hodgkin’s lymphoma
Rapidly enlarging thyroid mass
Hx of Hashimoto’s thyroiditis increases risk 60x
4:1 female predominance dysphagia, dyspnea, stridor, hoarseness, neck pain, facial edema, accompanied by “B” symptoms*
5 yr survival
Stage IE: 55%-80% Stage IIE: 20%-50% Stage IIE/IV: 15%-35%
Non-surgical
Combined radiation Chemotherapy (CHOP**)
*B symptoms = fever, night sweats, chills, weight loss >10% in 6 mo
Approach to Thyroid Nodule
** CHOP = cyclophosphamide, adriamycin, vincristine, prednisone
Treatment
Radioiodine therapy
Chemotherapy and/or radiotherapy Surgical excision
Indications
Treatment of hyperthyroidism
After surgery as adjuvant treatment of intermediate-high risk papillary or follicular carcinoma
Recurrent/residual medullary CA, anaplastic CA or thyroid lymphoma
Nodule that is suspicious on FNA cytology
Malignancy other than anaplastic CA or thyroid lymphoma
Mass that on is benign on FNA but increasing in size on serial imaging and/or >3-4 cm in size
Hyperthyroidism not amenable to medical therapy
Indications for Post-Operative Radioactive Iodine Ablation – I131
Adjuvant therapy: decrease recurrent disease RAI therapy: treat persistent cancer
Hematogenous
Capsular/vascular invasion Invasion influences prognosis
Fs – Follicular cancer Far away mets Female (3:1)
NOT FNA (cannot be diagnosed by FNA) Favourable prognosis
92% at 10 yr
Small tumours: Near total thyroidectomy/lobectomy/ isthmectomy Large/diffuse tumours: Total thyroidectomy
• allpatientswiththyroidnodulesrequireevaluationofserumTSHandultrasound
• intermediate-highsuspicionnodule>1cmandlowsuspicionnodule>1.5cmshouldundergoFNA
• nodules<1cmwithclinicalsymptomsorlymphadenopathymayrequirefurtherevaluation
• whenperformingrepeatFNAoninitiallynon-diagnosticnodules,U/S-guidedFNAshouldbeemployed • nuclearscanninghasminimalvalueintheinvestigationofthethyroidnodule
Table 20. Management of the Thyroid Nodule
*U/S findings: cystic: risk of malignancy <1%; solid: risk of malignancy ~10%; solid with cystic components: risk of malignancy same as if solid