Thyroid Flashcards
Thyroid exam 6 in neck
2 masses: Tongue protrusion & swallow + Cervical LNs
2 vascular: thyroid bruit and carotid pulse(Berrys sign)
2 respi: tracheal deviation and retrosternal extension
6 eyes of thyroid exam
2 mvmt: opthalmoplegia and lid lag
4 lid retraction, chemosis, proptosis, exophthalmos
6 arm steps of thyroid exam
Myopathy
Hyporeflexia
Tremors
Pulse
Palms
Nails
Treatment options for multinodular goitre
- Observation: Sx,PE,TFT and US
- Levothyroxine
- Ablation
- RAI
- Thyroidectomy
Marker for medullary thyroid cancer surveillance
Calcitonin
Types of thyroid cancer with good RAI uptake
Papillary and follicular
High risk features of thyroid nodules
- Solid
- Hypoechoic
- Microcalcifications
- Absence of halo
- Irregular margins
- Taller than wide
- Increased vascularity
TIRADS level where biopsy is recommended
4 and above
Difference between total and modified radical neck dissection
Sparing of one or all of SCM, IJV and CN XI
Boundaries of anterior neck
Hyoid bone, eternal notch, 2 SCMs?
Cutoff on FNAC score for requiring surgery and cannot offer follow up as treatment option
Bethesda 4
What is important to test in Medullary Thyroid cancer
For underlying MEN syndrome(Multiple Endocrine Neoplasia)
Sx of thyroid cancer
- Neck swelling
- LOA, LOW, Fever
- Compressive Sx( Esp in anaplastic)
- Dyspnea
- Dysphagia
- Dysarthria
- SVCO/ Pemberton - Sx of Horner’s syndrome
- Sx of metastasis
- Sx of Hyperthyroidism(uncommon)
- Diarrhea and facial flushing: Paraneoplastic syndrome of MTC
- B- symptoms of Fever, LOW, night sweats in Thyroid lymphoma
Signs of thyroid cancer
- Midline thyroid nodule/mass
- Solitary more common in papillary and follicular
- Diffuse mass more common in medullary and anaplastic
- Nodular, hard with irregular edges - Cervical Lnopathy
- Berry’s sign: Carotid pulse masked by malignant infiltration
RFs of papillary thyroid cancer
- Radiation exposure
- Polyposis syndromes eg Gardners/FAP
- Cowden syndrome
Tends to mets to LNs
RFs of follicular thyroid ca
- Radiation exposure
- Cowden syndrome
RFs of Medullary thyroic cancer
- MEN 2A or 2B-> Almost 100% incidence(Prophylactic thyroidectomy in some countries)
- Sporadic
- FHx of calcium problems
RFs for anaplastic thyroid cancer
- Long standing goiter
- Previous differentiated thyroid Ca
Thyroid cancer risk stratification systems
- TI RADs for malignancy risk on US
- Bethesda classification for FNA specimen results
Bethesda 1 is nondiagnostic NOT benign
Bethesda 4 requires diagnostic hemithyroidectomy as FNAC cannot identify capsular/vascular invasion - AJCC for staging
- ATA for selecting nodules for FNAC based on US
High risk features on ultrasound for thyroid cancer
- Heterogenous with solid hypoechoic nodules
- Irregular margins
- Taller than wide
- Micro calcifications
- Hypervascularity
- Extrathyroidal extension
T staging of thyroid cancer
T1: Tumor <1cm
T2: 1-2cm
T3a: 2-4cm
T3b: Extrathyroidal invasion only into strap muscles
T4a: Invasion into subcut soft tissue, larynx, trachea, esophagus or RLN
T4b: Invasion into prevertebral fascia, encasing carotid artery or mediastinal vessels
Indications for total thyroidectomy for thyroid cancer
- Tumor >4cm
- FHx of thyroid ca
- Medullary or anaplastic thyroid cancer
- RAI required
Thyroid cancers amenable to RAI for metastasis
PTC and FTC
Precautions for RAI mx of thyroid Ca
avoid children, elderly, no unprotected sex, no sharing toilet unless double flush, avoid childbearing for 6-12 months
Cx of thyroidectomy
- Vocal cord palsy: Bilateral RLN injury can lead to stridor and respiratory distress
- SLN injury affecting cricothyroid and voice
- Postoperative hypocalcemia due to ischemia of the parathyroids
- Neck hematoma
- Tracheal injury and necrosis
Rarer Cx - Tracheomalacia
- Horner’s syndrome
- Chyle leak
- Esophageal injury: Heralded by neck subcutaneous emphysema
