Thyroid Cancer

Question 2

 40 year old healthy female for a routine exam

 You see & palpate a 2 cm right-sided neck lump:
 non-tender, well-circumscribed & freely moveable
 no palpable nodes or other masses

 The rest of your exam is negative

- characterize this ultrasound finding. What’s next to do?

Answer 2

2 cm solid nodule

• hypoechoic
• irregular border
• wider than tall
• microcalcifications noticeable.
• given that it is irregular with microcalcifications, an FNA od the node whould beone. FNA would show epithlial cells in a papillar fomration from a pillary thyroid carcinoma. nuclear grooves are also apparent.

Question 4

which gender is more likely to be affected by thyroid cancer?

Answer 4

WOMEN are three times more common than men. it is the fastest rising incidence of all cancers in the past decade

Question 5

___ THYROID CANCER is the most common.

• usually diagnosis is made iwth a __ __ BIOPSY.
• the classic findings of papillary thyroid cancer is __ CELLS, __ __ INCLUSIONS, and __ BODIES.
• usually more AGGRESSIVE, tall looking cell and diffuse __

Answer 5

PAPILLARY THYROID CANCER is the most common.

• usually diagnosis is made iwth a FINE NEED BIOPSY.
• the classic findings of papillary thyroid cancer is EPITHELIAL CELLS, INTRA NUCLEAR INCLUSIONS, and PSAMMOMA BODIES.
• usually more AGGRESSIVE, tall looking cell and diffuse SCLEROSING

Question 6

5 classifications of thyroid cancer, what is the most common?

Answer 6

1. differentiated thyroid cancer (most common)- papillar, folluclar, hurthle cell
2. poorly differentiated
3. medullary
4. anaplastic
5. thyroid lymphoma

Question 8

outline the different types of cancers that are more and more de-differentiated

Answer 8

Question 9

SURGERY

• should be done with __ TO __ MONTHS of diagnosis
• near-total ___ usually recommended for leasions >__CM.
• if under 1 cm, it’s called a __ and not treated aggressively. We should actively surveille.
• recent ATA guidelines suggest the option for a __ for low risk patients.

Answer 9

• should be done with 6 TO 12 MONTHS of diagnosis
• near-total THYROIDECTOMY usually recommended for leasions >1CM.
• if under 1 cm, it’s called a MICROCARINOMA and not treated aggressively. We should actively surveille.
• recent ATA guidelines suggest the option for a lobectomy for low risk patients.

Question 10

T/F we should start screening for thyroid cancer

Answer 10

false. screening that results in the identification of indolent thyroid cancers and treatment of these overdiagnosed cancers may increase the risk of patient harms.

Question 12

pathogenesis of thyroid cancers

SPONTANEOUS or __-induced chromosomal gene __: usually from chimeric genes like RET/PTC. BRAF V600E.

• Unregulated __ KINASE activity which increases tumor development and growth
• activatingmutations in __ genes like RAS which can cause __- __ Dysregulation
• Silencing of tumor ___ genes like DNA HYPERMETHYLATION.
• only 5% of all papillary cancers are familial

Answer 12

SPONTANEOUS or RADIATION-induced chromosomal gene REARRANGEMENT: usually from chimeric genes like RET/PTC. BRAF V600E.

• Unregulated TYROSINE KINASE activity which increases tumor development and growth
• activatingmutations in REGULATOR genes like RAS which can cause CELL- CYCLE Dysregulation
• Silencing of tumor SUPPRESSOR genes like DNA HYPERMETHYLATION.
• only 5% of all papillary cancers are familial

Question 15

5 steps to the post-operative plan

Answer 15

after surgery:

1. evaluate final pathology
2. staging to help predict mortality and recurrence
3. thyroid hormone replacement and intensity
4. discuss possible need for radioactive iodine
5. outline follow up plan

Question 16

most staging systems are designed to predict the risk of moratlity. what are the two staging systems

Answer 16

TNM system; tumor size, Node infiltratio, mets.

MACIS system; takes into account age, size, invasion, resection, mets

Question 17

low risk patients with differentiated thyroid cancer usually die from:

Question 18

 Total thyroidectomy patients all require lifelong Rx with ___ (L-T4)
 Lobectomy patients (all low risk) may not need.

 Initial goal of therapy: to reduce TSH __ __ (TSH may be a __ factor)
 May reduce recurrence rate by factor of 2-3
 Often thyroid hormone doses 25-50 mcg above usual

 Caution in elderly; increase risk __ & __

 Risk of Recurrence guides __ of Rx.

 In low risk patients or those with “excellent response”,
we can often safely target a normal range __

Answer 18

 Total thyroidectomy patients all require lifelong Rx with levothyroxine (L-T4)
 Lobectomy patients (all low risk) may not need.

 Initial goal of therapy: to reduce TSH below normal (TSH may be a growth factor)
 May reduce recurrence rate by factor of 2-3
 Often thyroid hormone doses 25-50 mcg above usual

 Caution in elderly; increase risk osteopenia & Afib
 Risk of Recurrence guides intensity of Rx.

 In low risk patients or those with “excellent response”,
we can often safely target a normal range TSH

Question 19

most common form of thyroid cancer

Answer 19

papillary cancer. Form of differentiated thyroid cancer

Question 20

Radioactive iodine is a conjugate therapy to thyroid cancer (in addition to surgery). it specifically gets taken up into __ __ cells.

• causes __ by emitting __ decay particles.

it’s generally well tolerated, casuing some mild radiation thyroiditis, __ and __ pain, usually self limited.

Answer 20

Radioactive iodine is a conjugate therapy to thyroid cancer (in addition to surgery). it specifically gets taken up into Follicular thyroid cells.

• causes cytotoxicity by emitting beta decay particles.

it’s generally well tolerated, casuing some mild radiation thyroiditis, neck and jaw pain, usually self limited.

Question 21

RAI potential benefits and risks

Answer 21

pros: destroys residual microscopic disease, destroys remnant normal thyroid tissue, allows ideal future monitoring. May treat and identify metastatic disease

Risks; treatment of low risk disease with RAI is CONTROVERSIAL. May not make low recurrence risk cancer any lower.

• no benefit to reduce mortality in low risk patients.

at high doses, can cause salivary gland injury, tear duct fibrosis, gonadal or bone marrow toxicity.

• possible increased risk for second malignancy.
• deicsion for RAI treatment is individualized with the patient after review of surgcial and patholoy reports.

Question 22

Follow up tools after treating thyroid cancer

1. __ __ level which is a tumour marker after a total thyroidectomy.
2. __ __ every 1-2 years for 1st few years post op.

Answer 22

1. serum thyroglobulin level which is a tumour marker after a total thyroidectomy.
2. neck ultrasound every 1-2 years for 1st few years post op.

Question 23

copy this out. general management of thyroid cancer

Question 24

Metastases:
30% of __ may have cervical or mediastinal metastases at initial surgery, but Does not significantly affect overall prognosis in younger patients

• distant metases are more common in __ thyroid cancer.
• most common mets are in the __ and ___.

rarely in the brain, kidney, adrenal, liver, skin, soft tissues.

Answer 24

30% of papillary may have cervical or mediastinal metastases at initial surgery, but Does not significantly affect overall prognosis in younger patients

• distant metases are more common in follicular thyroid cancer.
• most common mets are in the lung and bone.

rarely in the brain, kidney, adrenal, liver, skin, soft tissues.

Question 25

options for treatment for recurrences

Answer 25

• not all recurrent/persistent neck disease need treatment
• surgery; for restable disease in neck or solitary mets
• radio iodine Rx; more effecitve to stabilize pulmonary metastases, resistance can develop to RAI.
• advent of increasing number of oral tyrosine kinase inhibitors: substantial breakthrough

Question 26

t/f you can diagnose follicular thyroid cancer using fine needly biopsy

Answer 26

false, cannot diagnose with FNA. need to demonstrate vascular/capsular invasion.

Question 27

MEDULLARY THYROID CANCER is derived from __/ __ cells that produce ___. (which is used as a marker)

• most are sporadic, but 20% of cases are inherited. All incidenceds require genetic testing RET Proto-ongogene.
• 50% have at least local neck metastases at Diagnosis.
• treatment is ___. it cannot uptake ___ and are insensitive to ___.
• 10 year survival: age <40: 75%, age>40: 50%

Answer 27

MEDULLARY THYROID CANCER is deficed from parafollicular C cells that produce calcitonin. (which is used as a marker)

• most are sporadic, but 20% of cases are inherited. All incidenceds require genetic testing RET Proto-ongogene.
• 50% have at least local neck metastases at Diagnosis.
• treatment is surgical. it cannot uptake iodine and are insensitive to radiation.
• 10 year survival: age <40: 75%, age>40: 50%

Question 28

one of the most aggressive human tumors with a poor prognosis. often called Orphan Disease

Answer 28

Anaplastic thyroid cancer. rare, fails to respond to therapy. many patients die of suffocation within 6 months of presentation

Question 29

Answer 29

Question 30

lymphoma often has a similar presentation to anaplastic thyroid cancer with rapid onset of large firm mass. how is its natural history idfferent?

Answer 30

it is often uncommon but it is very sensitive to radiation and chemotherapy with a good progrnosis, compared to anaplastic thyroid cancer that doesn't have many treatment options. - hematologists usually direct lymphoma care

Question 31