Thyroid Tumors/Cancers Flashcards
What are the two benign tumors of the thyroid?
Hyperplastic adenomatoid nodules
Follicular adenomas
What are the 4 malignant tumors of the thyroid gland?
Papillary thyroid carcinoma
Follicular cell carcinoma
Anaplastic carcinoma
Medullary carcinoma
What is the most important morph feature when diagnosing a follicular adenoma?
Evaluate the capsule. Adenomas will have a very well demarcated, intact capsule with no invasion of surrounding tissue.
What is the patho of a follicular adenoma?
Gain of function mutation in the TSH receptor
What would the radioactive screening show for a follicular adenoma and why?
If its non functioning, It would be cold because it takes up less iodine than normal functioning thyroid tissue.
What are the 4 major malignancies of the thyroid gland, which one is most common, and what is the peak age?
Papillary carcinoma, follicular carcinoma, anaplastic carcinoma, and medullary carcinoma. Pap is most common
25-50 years of age.
What do all of the carcinomas of the thyroid have in common except medullary?
They derive from the follicular epithelium
What does t1, t2, t3, and t4 mean for staging of thyroid carcinoma?
T1: tumor is less than 2cm
T2: tumor is between 2 and 4 cm
T3: greater than 4 and can invade strap muscles
T4: invasions belong strap muscles
What does NO and N1, and MO and M1 mean for staging of thyroid carcinoma?
NO is no lymph node, and N1 means regional LN involvement.
MO is no distant metastasis and M1 means distant metastasis.
What is the signaling pathway mutated in follicular cell derived malignancies?
Growth factor receptor signaling pathway
What are the two main genetic mutations for papillary carcinomas?
RET and BRAF
Histologically, what is the diagnostic feature of papillary thyroid carcinoma?
Enraged nuclei with a clear appearance.
What are two other histo features we are looking for in papillary carcinoma?
Papillary architecture and psammoma bodies
What is the most common variant of papillary carcinoma and what are two main differences between it and normal papillary carcinoma?
Follicular variant.
More follicular architecture but still the same nuclear features
higher prevalence of RAS mutations than BRAF or RET
What are two main differences in the Tall Cell variant version of papillary carcinoma?
Typically in older patients and very aggressive in its invasion.
3 differences between the diffuse sclerosing variant and conventional papillary?
Kids and young people
Higher incidence of distant metastasis
Lack BRAF but have RET mutations
Not only is papillary carcinoma the most common form of thyroid cancer, but it is also associated more than any other thyroid cancer with what?
Previous exposure to radiation
Two tests for determining papillary carcinomas?
Radionuclide and fine needle aspiration
What will papillary carcinomas show up as on radionuclide?
Cold nodules
Overall, what is the prognosis of papillary carcinoma?
Very good.
What conditions/situations are follicular carcinomas more common?
Areas with dietary iodine deficiency
Gender and age peak of follicular carcinoma?
Women and 40-60
2 key histo properties of follicular carcinoma to know?
Invade the capsule
Invade vasculature
What is a big difference between invasion between papillary and follicular carcinoma?
Pap goes to regional LN and follicular rarely involve regional LN
2 key features of anaplastic cancer clinically?
Highly aggressive and high mortality
Much older patients
3 histo features of anaplastic carcinoma?
Giants cells, spindle cells, and mixed giant and spindle cells
What are two mutations for all follicular neoplasms?
RAS and PTEN
What is a unique mutations specific to follicular carcinoma?
Fusion gene PAX8-PPARG
What is the 1 mutation for Anaplastic carcinoma?
TP53
Where do medullary carcinomas arise from? What type of tumor is a medullary carcinoma?
Neuroendocrine tumor arising from C cells
What is the most common mutation for a medullary carcinoma?
RET
What is the result on radionuclide test for follicular carcinoma?
Cold
What are the two types of medullary carcinoma and which one is more common?
Sporadic (70%) and familial (30%)
What syndrome is the familial type associated with?
Men type 2a and b
2 histo features of medullary carcinoma?
Amyloid deposits and c cell hyperplasia
What are two features unique to familial medullary carcinoma?
Bilateral and multicentric, meaning it has multiple spots of origin
Prognosis of sporadic vs. familial?
Familial is much better
Talk about the 3 levels of prognosis for 10 year survival rates for medullary?
90% if its just in the thyroid gland
70% if its in the cervical LN
20% if there is distant metastasis
