Endocrine: Thyroid Pathology

Front 1

4 types of thyroididis.

Back 1

1. acute thyroiditis
2. subacute grannulomatous thyroiditis (DeQuervain's)
3. Hashimoto's thyroditis
4. fibrous (Riedel) thyroiditis

Front 2

What type of thyroiditis is this?

- begins as headache and myalgia
- painful neck that raidiates to the jaw
- biopsy: giant cells, damaged/collapsed follicles

Back 2

subacute granulomatous thyroiditis (DeQuervains)
- viral or postviral process

Front 3

What is the most common cause of hypothyroidism in US adults?

Back 3

Hashimoto's thyroiditis

Front 4

Pathogenesis of Hashimoto's thyroiditis.

Back 4

1. CD4 T cell sensitization to thyroid antigen
2. helper T cells
3. CD8 toxicity through Fas-L
3. CD4 Th1 -> INF -> macrophage
3. plasma cell -> antibodies to TG, TSHR, thyroid peroxidase -> Fc receptor of NK cells
-

Front 5

What is this disease?

- enlarged nodular thyroid
- geminal centers, lymphocytic infiltration, Hurthle cells in atrophic follicles
- hypothyroid

Back 5

Hashimoto's thyroiditis

Front 6

What type of thyroiditis is this?

Back 6

Subacute granulomatous thyroiditis
- giant cells
- collapsed follicles
- surrounding macrophages, lymphocytes, plasma cells

Front 7

What type of thyroiditis is this?

Back 7

Hashimoto's thyroiditis
- hurthle cell: metaplasia
- germinal center
- atrophic follicles
- lymphocytic infiltration

Front 8

What is this disease?

- anti-TPO stain

Back 8

Hashimoto's thyroiditis
- diagnostic test of choice
- other test: anti-TG stain

Front 9

Compare Hashimoto's and Riedel thyroiditis.

Back 9

Front 10

What type of thyroiditis is this?

- rock hard fixed mass
- hypothyroid
- fibrosis

Back 10

Reidel thyroiditis

Front 11

In which type of thyoiditis would you see increased incidence of papillary carcinoma and B cell malignant lymphoma?

Back 11

Hashimoto's thyroiditis

Front 12

What is Hashimoto's toxicosis?

Back 12

initial hyperthyroidism due to inflammation

Front 13

What is this disease?

- hyperfunctioning, hyperplastic goiter
- exophthalmos
- pre-tibial, ankle edema
- micro: papillary hyperplasia/infoldings

Back 13

Grave's disease
- IgG to TSHR and mimics the action of TSH (increase cAMP)

Front 14

What is this disease?

- gross: diffusely enlarged ithyroid
- symptoms: goiter, exophthalmos, ankle edema

Back 14

Graves disease
- IgG against TSHR
- papillary infoldings, hyperplasia

Front 15

What is the most common cause of this?

- diffuse nontoxic goiter

Back 15

iodine deficiency
- high TSH -> follicular cell hyperplasia and hypertrophy
- goitrogens: cabbage, brussel sprouts, cassava

Front 16

Mechanism of action of goitrogens such as cabbage, brussel sprouts, cassava.

Back 16

inhibit iodide transport within thyroid

Front 17

What is the most common type of goiter in the US?

Back 17

diffuse nodular goiter

Front 18

What % thyroid nodules are neoplastic?

Back 18

low
if neoplastic, 90% are adenomas

Front 19

Benign or malignant?

- "hot" nodules on scintiscan

Back 19

- most likely benign
- likely to be malignant in young people

Front 20

A thyroid nodule in a male is more likely to be ____ (benign/neoplastic).

Back 20

neoplastic

Front 21

Low dose therapeutic radiation has risk for what type of thyroid diseases?

Back 21

- nodular goiter
- adenomas (single nodular or enlarged multinodular)
- chronic lymphocytic thyroiditis
- papillary carcinoma (more multicentric and bilateral)

Front 22

What type of goiter is this?

- euthyroid
- colloid rich
- micro: areas of hemosiderin, cystic degeneration, calcifications, fibrosis

Back 22

nodular goiter (adenomatous)

Front 23

What is the initial step in diagnosing thyroid nodules?

Back 23

fine needle aspiration
- 25 or 27 gauge needle
- 4-6 samples

Front 24

What is this disease? What would you see on histologic section?

Back 24

follicular adenoma
- gross: solitary, discrete, well circumscribed, connective tissue capsule
- micro: hurthle cells. Do not transgress the capsule, do not invade blood vessels.

Front 25

Pathogenesis of follicular adenomas.

Back 25

- gain of function on TSHR or alpha subunit of Gs cause excess cAMP

Front 26

Name the four malignant thyroid tumors. Which is the most common?

Back 26

- papillary carcinoma (most common)
- follicular carcinoma
- medullary carcinoma
- anaplastic carcinoma (worst prognosis)

Front 27

Pathogenesis of papillary carcinoma.

Back 27

- reciprocal translocation between chromosome 10 and 17 which creates ret/PTC oncogene
- consequence of irradiation during first 2 decades of life

Front 28

Is high dose I131 tumorogenic?

Back 28

No. Only therapeutic radiation is tumorogenic.

Front 29

Which malignant papillary carcinoma?

- gross: gray-white, firm, calcifications
- micro: orphan annie nuclei, psammoma bodies
- invading lymphatics

Back 29

papillary carcinoma
- lots of occult cyts, so treatment is to remove all thyroid tissue.

Front 30

What is this thyroid tumor?

Back 30

papillary carcinoma
- gross: gray-white, firm, often with calcifications, cystic change
- micro: orphan annie nuclei, psommoma bodies.
- lymphatic spread

Front 31

What is the prognosis of papillary carcinoma?

Back 31

90% survival at 20 yrs

favorable factors
- female
- under age 20
- confinement to thyroid gland

Front 32

Pathogenesis of follicular carcinoma.

Back 32

fusion gene PAX8-PPAR-gamma1

Front 33

What thyroid condition may develop into follicular carcinoma?

Back 33

- multinodular goiters
- but most are de novo

Front 34

What is this thyroid tumor?

- capsular, vascular invasion
- sometimes "warm"
- tend to metastasize by hematogenous route to lungs and bones

Back 34

follicular carcinoma

Front 35

What is the prognosis of follicular carcinoma?

Back 35

- good prognosis when it is well circumscribed

Front 36

What is this thyroid tumor?

Back 36

follicular carcinoma
- neoplastic cells invading fibrous capsule
- vascular invasion

Front 37

Pathogenesis of medullary carcinoma.

Back 37

- cancer of parafollicular C cells: secrete calcitonin
- 20% associated with MEN syndromes IIa and IIb

Front 38

What is this thyroid tumor?

micro
- round to polygonal cells in sheets with amyloid stroma

Back 38

medullary carcinoma

Front 39

What is the prognosis of medullary carcinoma?

Back 39

- familial medullary carcinoma: fairly indolent
- poorer prognosis if associated with MEN IIb.

Front 40

What is this thyroid tumor?

Back 40

medullary carcinoma
- abundant amyloid stroma between neoplastic cells
- neoplastic cells form sheets

Front 41

What is this?

- mucosal neuromas
- pheochromocytoma
- medullary carcinoma of thyroid

Back 41

MEN type IIB

Front 42

What is this?

- parathyroid hyperplasia
- pheochromocytoma
- medullary carcinoma of thyroid

Back 42

MEN type IIA

Front 43

What is this disease?

- neuromas in lips, tongue, buccal mucosa
- enlarged bubbery lips
- weakness, HTN, diarrhea
- lump in the neck

Back 43

MEN type IIB
- mucosal neuromas: plexiform
- pheochromocytoma (bilateral): weakness, HTN, diarrhea
- medullary carcinoma of thyroid: lump in the neck

Front 44

What is this disease?

- mucosal neuroma
- diarrhea, HTN
- lump in the neck

Back 44

MEN type IIB
- mucosal neuroma
- pheochromacytoma: diarrhea, HTN
- medullary carcinoma: lump in the neck. scerete calcitonin (see figure)

Front 45

What is this disease?

Back 45

anaplastic carcinoma of thyroid
- fatal within 1 year