Thyroid Cancer Flashcards
benign thyroid nodule - what %
ddx
75%
Colloid nodule (aka adenodmatoid nodule)
Follicular or Hurthle Cell adenoma
Simple cyst
RF Thy Ca
Radiation exposure - <30 Gy (lower dose worse)
- Increasing years since rad’n
- Younger age at ca dx
- Female
- Autoimmune thyroid dz
- Iodine insufficiency
- FHx
- Genetic d/o (MEN2, PTEN mut’n, DICER, FAP)
Bethesda scoring
- unsatisfactory - repeat FNA
- benign
- atypia/follicular lesion of undetermined significance
- follicular neoplasm
- suspicious for malignancy
- malignant
Bethesda scoring - what to do w each score
- repeat FNA
- clinical follow up
- lobectomy
- lobectomy
- thyroidectomy
- thyroidectomy
TIRADS
- what does it stands for
- features
Thyroid Imaging and Reporting Data System
- composition (cystic, spongiform, mixed or solid)
- echogenicity, (anechoic, hyperechoic, isoechoic, or hypoechoic),
- shape on transverse imaging (taller than wide or wider than tall),
- margin (smooth, ill-defined, lobulated, or with extrathyroidal extension)
- echogenic foci (none, comet-tail, macrocalcifications, rim calcifications, or punctate calcifications)
what is the single, most reliable feature associated with a lower risk of thyroid malignancy
Cystic or mixed composition, with a greater than 75% cystic component
what are features associated with a higher risk of malignancy on thyroid ultrasound
solid composition,
hypoechogenicity (darker)
micro calcifications
taller than wide shape on transverse imaging
lobulated or irregular margin (jagged)
punctate echogenic foci
intranodular vascular flow
what are features associated with a higher likelihood of being benign on thyroid ultrasound
egg shell calcifications
iso- to hyper echoic
translucent halo
smoother border
peripheral vascular flow
what are the % of thyroid ca
papillary 90+%
Follicular 5-10%
medullary <5%
what can be dx n thyroid nodule FNA
Papillary can be dx on FNA
Follicular cannot be dx on FNA, will be indeterminate
I131 for DTC - when to use
RAI to treat persistent disease or high risk recurrent
not for remnant ablation
ATA pediatric risk level: Low
- what does it mean
- initial post op staging
- TSH goal
- surveillance
- Disease grossly confined to the thyroid with N0 (no lymph node metastasis) or NX (no lymph nodes assessed) disease or patients with incidental metastatic lymph nodes in the central neck (N1a)
- Tg
- 0.5-1.0
-US at 6months then annually x5 years
- Tg on T4 q3-6 months for 2 years then annually
ATA pediatric risk level: Intermediate
- what does it mean
- initial post op staging
- TSH goal
- surveillance
- Extensive N1a or minimal N1b disease
- Presence of extrathyroidal extension or >6 metastatic lymph nodes (N1a) or lateral neck lymph node metastasis (N1b).
- TSH- stimulated Tg and diagnostic I123 scan
- 0.1-0.5
- US at 6 months, every 6-12 months for 5 years and then less frequently
- Tg on LT4 q3-6 months for 3 years and then annually
- consider TSH stimulated Tg +/- diagnostic I123 scan in 1-2 years in patients tx w I131
ATA pediatric risk level: High
- what does it mean
- initial post op staging
- TSH goal
- surveillance
- regionally extensive disease or locally invasive disease, with or without distant metastasis
- Presence of more than 10 metastatic lymph nodes or distant metastasis.
- TSH stimulated Tg and diagnostic I123 scan in all patients
- <0.1
- US at 6 months, every 6-12 months for 5 years and then less frequently
- Tg on LT4 every 3-6 months for 3 years and then annually
- TSH stimulated Tg +/- diagnostic I123 scan in 1-2 years in patients tx w I131
FTC - assoc w ?
I def
what is MTC
neuroendocrine cancer that derives from the neural crest and originated parafollicular C-cells of the thyroid gland
tumour markers MTC
calcitonin and carcinoembryonic antigen (CEA)
do not express the sodium-iodine symporter, and do not produce TG.
hematogenous spread of MTC
Lungs, bone liver
Sx of MTC
diarrhea
flushing
Cushing syndrome
tx thyroid storm
MMI
PTU
B-blocker
corticosteroids
potassium iodide
cholestyramine
Cowden syndrome
Autosomal dominant
-PTEN gene → LOF contributes to oncogenesis
Breast Ca
Follicular Thyroid Ca
Mucocutaneous symptoms
other malignancies like GU (endometrial cancer, RCC), testicular lipomatosis in men, esophageal glycogen acanthosis, polyps (gastric and duodenal), colorectal CA, colonic polyps, tumours and neurovascular malformations (dysplastic gangliocytoma of cerebellum), venous and cavernous angiomas, macrocephaly, ID, immune dysregulation
How do you differentiate between follicular adenoma and carcinoma?
You can only differentiate after surgical resection. Follicular cancer is identified when there are follicular cells in an encapsulated and/or one with vascular invasion
after TTx for papillary thyroid Ca, who should get WBS?
int and high risk
Types of thyroid cells
what response to TSH
Follicular cells:
- Respond to TSH
- Secrete Tg
Parafoll - do not
red flags in thy ca
Rapid growth of nodule
Compressive symptoms
Voice change/ hoarseness
how often do kids have mets in PTC
most will have LN mets at dx
still good prognosis
Prep for 131-I
Low-iodine diet
LT4 withdrawal (2-3 weeks) vs rhTSH
When does RAI uptake decrease?
w less degree of differentiation
what is the cure rate and prognosis with lung mets in PTC
Very hard to cure Lung mets
But won’t be fatal - they can live long with this
S/E of RAI
Short-term side effects of RAI treatment may include:
- Radiation thyroiditis
- Nausea and vomiting
- Sialadenitis
- Risk of thyroid storm
- Eyes: potential worsening of eye symptoms (if Graves) and can cause dry eyes
- Mouth: dry mouth, dental caries, taste changes
- Fertility: higher total dose of radiation reduces sperm counts
- Secondary malignancy: slightly increased risk of developing leukemia, stomach cancer, and salivary gland cancer
- Risk to others: need to follow precautions post treatment
- If lung mets there is a risk of pulmonary pneumonitis/fibrosis
Most common mutation in PTC
Children: RET/PTC
Adults: BRAF
