SFP: thyroid pathology II

Question 1

What might cause undetectable TSH?

Answer 1

Autoimmune hyperthyroidism, toxic goiter, toxic adenoma, exogenous thyroid overdose

Question 2

What may cause increased TSH?

Answer 2

Goiter, autoimmune disease (Hashimoto’s), hereditary defect in iodination

Question 3

What may cause increased TSH and T4?

Answer 3

Pituitary adenoma

Question 4

Nodules in what population tend to be neoplastic?

Answer 4

Young and old

Question 5

If a nodule is producing thyroid hormone (‘hot nodule’), is it more likely to be benign or malignant?

Answer 5

Benign

Question 6

What is goiter?

Answer 6

Enlargement of the thyroid gland

Question 7

What is the pathophysiology of goiter?

Answer 7

Impaired hormone synthesis increases TSH, which leads to hypertrophy and hyperplasia of thyroid follicular cells, leading to enlargement

Question 8

What is toxic goiter?

Answer 8

Goiter causing hyperthyroidism

Question 9

What is goitrous hypothyroidism?

Answer 9

Enlargement of the thyroid still cannot cause production of adequate hormone levels

Question 10

What is a common cause of goiter?

Answer 10

Deficient iodine

Question 11

Describe diffuse goiter.

Answer 11

A diffuse symmetric enlargement that resembles grave’s disease

Question 12

Describe nodular goiter.

Answer 12

Caused by repeated episodes of hyperplasia and involution

Question 13

Can adenomas in the thyroid become malignant?

Answer 13

Yes, slight chance

Question 14

What causes functional adenomas in the thyroid?

Answer 14

Gain of function in TSH receptor or alpha subunit of G protein resulting in overproduction of cAMP

Question 15

What is the gross appearance of follicular adenomas?

Answer 15

Solitary, smooth, well-circumscribed lesions

Question 16

What is the histology of follicular adenoma?

Answer 16

Lots of small follicles separated from normal thyroid by an intact capsule

Question 17

What genetic association is linked to papillary carcinoma?

Answer 17

Gain of function in RAS/BRAF in map kinase pathway or RET translocation

Question 18

What genetic association is linked to follicular carcinoma?

Answer 18

Gain of function in PI3K, loss of function in PTEN, gain of function in RAS, PAX8-PPARy translocation

Question 19

What genetic association is linked to medullary carcinomas?

Answer 19

RET mutation

Question 20

What genetic association is linked to anaplastic carcinomas?

Answer 20

P35 mutation

Question 21

What is an environmental risk for thyroid carcinomas?

Answer 21

Ionizing radiation

Question 22

What is papillary carcinoma?

Answer 22

An asymptomatic nodule associated with previous radiation

Question 23

Where does papillary carcinoma usually metastasize?

Answer 23

Cervical lymph nodes

Question 24

How does metastases to cervical lymph nodes influence prognosis of papillary carcinoma?

Answer 24

It doesn’t!!

Question 25

How is the prognosis of papillary carcinoma?

Answer 25

Really good!

Question 26

What are prognostic factors for papillary carcinoma?

Answer 26

Age, extrathyroidal extension, distant metastases

Question 27

What is the gross pathology of papillary carcinoma?

Answer 27

Fibrosis, calcification, or cystic change. May be solitary or multifocal and may be well-circumscribed or infiltrative. Overall, unspecific

Question 28

What is needed for definitive diagnosis of papillary carcinoma?

Answer 28

Nuclear features on microscopic exam!

Question 29

Describe histology of papillary carcinomas.

Answer 29

Branching papillae with fibrovascular cores, optically clear 'orphan Annie eye', nuclear grooves, cytoplasmic invaginations into the nucleus

Question 30

In what thyroid tumor do we see psammoma bodies?

Answer 30

Papillary carcinoma

Question 31

Describe follicular carcinoma.

Answer 31

More likely in women and increased with iodine deficient areas. They are painless, slow-growing, and less likely to be thyroid hormone producing

Question 32

What are prognostic factors of follicular carcinoma?

Answer 32

Stage at presentation and invasion

Question 33

What is the gross pathology of follicular carcinoma?

Answer 33

Solitary nodules…unspecific

Question 34

What is the histology of follicular carcinoma?

Answer 34

Nuclei lacking papillary carcinoma features, looks like adenoma but may invade the capsule

Question 35

What is medullary carcinoma?

Answer 35

Tumor of parafollicular cells that secrete calcitonin

Question 36

Are most medullary carcinomas sporadic or familial?

Answer 36

Sporadic

Question 37

In what thyroid tumor is amyloid found?

Answer 37

Medullary carcinoma

Question 38

What is c cell hyperplasia?

Answer 38

Precursor to medullary carcinomas in familial medullary carcinoma; clusters of c cells scattered throughout the parenchyma

Question 39

Describe gross pathology of medullary carcinoma.

Answer 39

Not encapsulated, gray tan, confined to one lobe if sporadic and bilateral if familial

Question 40

Describe histology of medullary carcinoma.

Answer 40

Amyloid stroma, secretory granules with stored calcitonin

Question 41

Describe anaplastic carcinoma.

Answer 41

Undifferentiated neoplasms that are the most aggressive thyroid carcinoma

Question 42

What is the pathogenesis of anaplastic carcinoma?

Answer 42

Evolution via dedifferentiation from more differentiated tumors via one or more genetic events; includes loss of p53

Question 43

Describe histology of anaplastic carcinoma.

Answer 43

Highly aplastic cells that may be pleomorphic, spindle cells, mixed spindle and giant cells, and small cells