E: Thyroid Pathology

Front 1

Describe the histological cell populations of the thyroid. The appearance/amount of which is dependent on demand for thyroid hormone?
- what are the C cells?

Back 1

acini/follicules
- the lining cells are the follicular epithelium, and it is their app./amount that is dependent on demand for thyroid hormone
- central colloid
- parafollicular cells (C-cells)
+ secrete calcitonin (lowers calcium); can see with immunostain.

Front 2

Should we excise *all* thyroid nodules?
- how should we triage?
- are most malignant?
- are lots of pt saved from death by surgery?
- will lots of pts die of thyroid cancer?

Back 2

No, it's impractical and may do more harm than good.
- triage them with FNA biopsy.
- no.
- no
- not many

Front 3

Re: FNA sample characteristics, tell if it's likely to be neoplastic.
- high amt. of colloid and low epithelial cellularity
- low colloid and high epithelial cellularity

Back 3

- non-neoplastic
- neoplastic

Front 4

When do we excise based on FNA results?

Back 4

when we think it's neoplastic.

Front 5

What are some benign thyroid conditions?

Back 5

- Multinodal Goiter (non toxic and toxic)
- diffuse toxic goiter (grave's dz)
- subacute (granulomatous) thyroiditis
- Hashimoto's thyroiditis
- Non-specific lymphocytic thyroiditis
- Reidel's thyroiditis

Front 6

Which dz is characterized by a spectrum of changes including follicular hyperplasia, colloid accumulation, and finally fodule formation after many cycles of the other two.
- common secondary changes cause by this issue?
- what are they at risk of developing?
+ gender predom?
+ sx?

Back 6

nodular goiter.
- fibrosis, hemorrhage, cyst formation, and dystrophic calcification.
- functioning (toxic) nodules
+ 10:1 F
+ less severe hyperT than Graves

Front 7

What is an autoimmune disorder characterized by diffuse goiter, hyperthyroidism, and exopthalmos (bulging of eyes out of orbit)?

Back 7

Grave's dz

Front 8

What is the most common cause of hyperT in pts under 40 years of age?

Back 8

Grave's dz.

Front 9

It usually presents itself as a waxy, discolored induration of the skin—classically described as having a so-called peau d'orange (orange peel) appearance—on the anterior aspect of the lower legs, spreading to the dorsum of the feet, or as a non-localised, non-pitting edema of the skin in the same areas.[2] In advanced cases, this may extend to the upper trunk (torso), upper extremities, face, neck, and ears.
- what is this?
- what is it a RARE complication of?

Back 9

- pre-tibial myxedema
- grave's dz

Front 10

What is another name for subacute thyroiditis?
- often follows what?
- presenting sx?
- gross?
- microscopically?

Back 10

granulomatous thyroiditis
- URI, often viral.
- neck pain, may have transient hyperthyroidism, then hypothyroidism
- enlarged, asymmetric, fibrotic thyroid.
- Initial acute inflammatory infiltrate, then granulomatous inflammation, with replacement of follicles by histiocytes and giant cells. Patchy fibrosis common.

Front 11

What is Hashimotot's thyroiditis? - pathogenesis?
- histologically?

Back 11

- classic autoimmune dz in which T4 helper cells are actv by virus/bact --> B-cells come into thyroid --> antibodies against thyroglobulin, microsolmal antigens, and/or TSH receptor.
- extensive lympho/plasma infiltrates... may form germinal centers (B-cels). There is also oncocytic metaplasia of follicular epitheium.

Front 12

What is oncocytosis?

What are Hurthle cells?

Back 12

Oncocytosis is a cellular feature characterized by the presence of a finely granular eosinophilic cytoplasm due to the accumulation of mitochondria. While this histologic trait can be found in normal tissues, it is also seen pathologically as a degenerative phenomenon.

enlarged epithelial cells in the thyroid with abundant eosinophilic granular cytoplasm as a result of altered mitochondria (oncocytosis).
- often seen in Hashimoto's thyroiditis

Front 13

Do you see fibrosis in Hashimoto's dz?
- clinical sx?
- tx?

Back 13

you can, particularly in late stage dz
- usually euthryoid in the initial phases but may be hyper- or hypothyroid. Late stage Hashimoto’s are often hypothyroid.
- thyroid replacement

Front 14

What neoplasms does Hashimoto's put you at elevated risk for?

Back 14

papillary carcinoma and primary thyroid lymphoma (especially extranodal marginal zone B cell lymphomas).

Front 15

What is a common incidental finding in surgical or autopsy thyroids? (up to 20%)
- gender predom? age?
- clincally?
- microscopically?

Back 15

non-specific lymphocytic thyroiditis
- F:M; incidence ^ w/ age
- usually euthyroid, may have low lvls of serum autoantib.
- focal interstitial collections of lymphocytes and plasma cells. NO Hurthle cells.

Front 16

Idiopathic fibrosclerosis involving the thyroid and the soft tissues of the neck is called...
- prevelance?
- description/pathologically?
- What does FNA yield?

Back 16

Reide's thyroiditis
- extremely rare
- Hard, “woody” thyroid fixed to adjacent structures in the neck. ....hyalinized fibrous tissue replacing thyroid.
- no cells, usually

Front 17

FNA results:
Abundant dense or watery colloid. Some follicular epithelium in flat sheets. Variable # of macrophages, a few Hurthle cells.
- likely dz?

Adenomatous nodules in this dz can be much more what?

Back 17

- Goiter
- cellular, mimicing follicular neoplasm

Front 18

FNA results:
Smear is dominated by numerous macrophages with some background colloid. There may or may not be some recognizably follicular cells.

Dz?

Back 18

cyst, usually due to cystic change in multinodular goiter.

Front 19

FNA results:
Reduced colloid, groups of follicular cells which may have atypia (mimicing papillary carcinoma), lymphocytes, flare cells.

dz?

Back 19

Grave's dz (diffuse toxic goiter).

Front 20

FNA results:
- background of lymphocytes and plasma cells can be extensive.

think what?

Help to differentiate?

Back 20

Lymphocytic/Hashimoto’s thyroiditis-cytology

Hashimoto's can have tons of Hurthle cells and reduced colloid.

Front 21

What are the 2 primary benign neoplasms of the thyroid?

A "hot" nodule on radioiodine scan is almost always (malignant/benign)?

Back 21

follicular adenoma and Hurthle cell ademona.

benign.

Front 22

Risk factors for thyroid cancer include what?

Which type of nodule is more suspicious for cancer, multinodular or solitary nodule?

Back 22

Male sex, age extremes, Xrt exposure, iodine deficiency.

solitary

Front 23

Solitary, benign, COLD nodule more prevalent in women than in men. It is complete encapsulated (thinly). The tumor does NOT invatde into the capsule, BV, or surrounding thyroid.
- dz?
- what 2 things can they be comprised of?
- tx?

Back 23

- follicular adenoma
- typical follicular cells or hurthle cells
- lobectomy.

Front 24

75% of all thyroid malignancies are what?
- gender predom? age?
- prog?
- regional lymph mets common?
- distant blood borne mets?

Back 24

Papillary thyroid carcinoma.
- Female; 20s-40s
- good in young women
- yes, can be the presenting sign.
- uncommon

Front 25

What is *REQUIRED* for dx of papillary carcinoma?

Is papillary architecture always required for dx?

Back 25

- characteristic cytologic appearance: croweded cells, nuclei w/ finely dispersed chromatin, irregular nuclear contour (grooves and intranuclear pseudoinclusions), psammoma bodies may be present.

no.

Front 26

Cold thyroid nodule, more common in women. Incidence peaks in 5th and 6th decade. May present w/ mets, esp to bone and lung. Usually a solitary lesion.
- dz?
- mech of spread?
- tx?

Back 26

- Follicular or Hurthle cell carcinoma
- blood borne mets
- lobectomy to total thyroidectomy.

Front 27

What is a medullary carcinoma?
- what does it secrete?
- usually sporadic or familial?
- what types of characteristic stroma can be present with this neoplasm?
- histological appearance?

Back 27

Neuroendocrine tumor arising from the parafollicular cells = “C” cells.
- calcitonin
- sporadic.
- amyloid
- neuroendocrine w/ 'packets' of uniform round to oval cells and spindle shaped cells.

Front 28

What is virtually dx of medullary carcinoma?

Back 28

calcitonin elevation + thyroid nodule.

Front 29

What is the most malignant thyroid neoplasm?
- prevalence? gender? age?
- capable of mets?
- how does it kill?
- amenable to tx?

Back 29

Anaplastic carcinoma = one of the most aggressive human neoplasms.
- rare; 3:1 F, >60y
- yes
- Usually strangles the patient with local infiltration of vital structures in the neck.
- no.

Front 30

Are primary thyroid carcinomas typical? What types of lymphomas are seen instead?

Back 30

no, they're unusual.
- B-cell (anaplastic large cell lymphoma or mantle cell lymphoma)

Front 31

Can cytology distinguish between follicular adenomas and follicular carcinomas?

Back 31

NO.

Front 32

Describe the two variants of papillary carcinoma cytology.

Back 32

Follicular variant of papillary carcinoma
- May cytologically mimic follicular neoplasm, but often has nuclear features of papillary carcinoma

Tall cell variant of papillary carcinoma
- Aggressive variant, older patients, often have extrathyroidal extension.