Thyroid cancer Flashcards
What are the risk factors of thyroid cancer?
- Family Hx
- < 30 YO; >60 YO
- Male
- Hx of radiation exposure: Risks Papillary Thyroid CA
- Background of Hashimoto’s Thyroiditis: Risks thyroid lymphoma
- Men 2 Syndrome: risks Medullary Thyroid CA
- Rapidly enlarging thyroid w Hoarseness, Dysphagia, Lymphadenopathy: suspect Anaplastic
What is the diagnostic criteria for Hashimoto’s Thyroiditis?
1) Absence of nodules in a diffusely enlarged thyroid
2) Congruous TFT indicating primary hypothyroid
3) Presence of Thyroid Peroxidase Ab
Does NOT require USS or FNA for Dx!
What are the features of malignant thyroid nodules on ultrasound?
- Lymphadenopathy / Local Invasion: sign of aggressiveness
- Micro Calcifications ≤1mm
- Coarse Calcifications in a solid nodule
- Markedly HYPOechoic echotexture with solid consistency
- Irregular, infiltrating margins
- Intranodular flow with hypoechogenicity/ irregular margins
- Absence of Halo
- Thick, irregular Halo (sign of increased peripheral vascularity)
- Tall & Thin on transverse scan (taller more than wide)
What is the management of a hot nodule?
Explains HyperT if pt’s TFT shows HyperT
Does not require Biopsy – Toxic Thyroid nodules tend to be indolent and less aggressive
Treat w/ hemi/total thyroidectomy OR Radioactive Iodine treatment
What is the management of a cold nodule?
Nodule is inactive and does not produce T4
Require biopsy via FNAC 🡪 Bethesda Classification
What are the clinical features of MEN2A?
medullary thyroid CA; pheochromocytoma, Primary Hyperparathyroid
What are the clinical features of MEN2B?
medullary thyroid CA; pheochromocytoma Marfanoid Body Habitus
What are the clinical features of MEN1?
pituitary; parathyroid; pancreatic tumors
What is the Bethesda System for Reporting Thyroid Cytopathology?
- Category I: Non diagnostic
- Category II: Benign
- Category III: Atypia of undetermined significance (AUS) or follicular lesion of undetermined significance
- Category IV: Follicular neoplasm or suspicious for a follicular neoplasm
- Category V: Suspicious for malignancy
- Category VI: Malignant
What are the indications for FNAC?
- Suspicious features: >1cm
- Solid: >1.5cm
- Not suspicious: >2cm
What is the management of differentiated thyroid cancers?
Either hemi / total thyroidectomy +/- Radial Neck Dissection
- Hemi Thyroidectomy : if <1cm & low risk (no local or distant metastases, no invasion of loco- regional tissues)
- Total Thyroidectomy: MAJORITY of pt, if: >4cm OR extrathyroidal extension OR cervical LN involvement
- +/- Lymph node dissection: Most common site of nodal mets is central neck (VI)
Consider adjuvant RAI if indicated (C/I in hemithyroidectomy)
With adjuvant TSH suppression via T4 provision
- Regardless of RAI or not, and Total / Hemi
- Only difference is degree of suppression administered
F/U: Check TSH, Thyroglobulin and USS neck
Palliative: Sorafenib
What is the management of medullary thyroid cancers?
Pre-op
- Calcitonin and CEA (Tumor markers baseline)
- TRO Men syndrome: Serum Calcium, serum/urine metanephrines & catecholamines, Germline RET mutation analysis
- Neck Ultrasonography
No cervical lymph node involvement: Total thyroidectomy with bilateral central compartment dissection (level VI nodes)
Cervical lymph node involvement: Total thyroidectomy with bilateral central compartment dissection and dissection of the involved lateral neck compartment(s)
F/U: Calcitonin & CEA; USS
What is the benefits of total thyroidectomy?
Ability to use adjuvant radioiodine to ablate residual Ca post-op
Ability to use serum thyroglobulin as a tumor marker for recurrence
Preferred for Multifocal disease
Much lower risk of recurrence than in lobectomy
What is the cons of total thyroidectomy?
Risk of bilateral recurrent laryngeal nerve injury
Risk of severe HypoCa – May be transient or chronic
Lifelong T4 replacement – VS hemi which MAY SPARE pt from lifelong replacement
What are the cons of a radical neck dissection?
Carotid blowout
Injury to nerves – vagus (vocal cord paralysis), cervical sympathetic chain (Horner’s), mandibular branch of facial (lower lip weakness)
