Thyroid Pathology- Hunt Flashcards Preview

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Flashcards in Thyroid Pathology- Hunt Deck (23):
1

 

What are three diseases that cause thyroid inflammation?

Give the eponymous names and the clinical names

 

 

 

  1. Subacute granulomatous thyroiditis
    • de Quervain thyroiditis
  2. Chronic Lymphocytic thyroiditis
    • Hashimoto's thyroiditis
  3. Fibrosing thyroiditis
    • Riedel thyroiditis

2

 

What is the pathology behind Hashimoto's thyroiditis?

 

What tests can confirm the diagnosis?

 

It is an autoimmune disease that produces auto-antibodies

 

Tests for anti-TPO and anti-Tg

3

 

What does the thyroid look like grossly in hashimoto's thyroiditis?

 

What does the thyroid look like on histology?

 

Diffuse enlargment

 

Thyroid will show lymphocyte infiltration and formation of germinal centers.  Hurthle cells (large, pink) will also be found.  

4

 

What is the pathology behind subacute thyroiditis (de Quervain thyroiditis)?

 

What does the progression of the disease look like?

 

Unknown, but it is believed to be related to viral or post-viral states.

 

Painful, but self-limited

5

 

What does de Quervain thyroiditis look like on histology?

 

 

 

Lots of neutrophil infiltrate

 

Giant cell granulomas

6

 

What is the pathology behind fibrous thyroiditis (Riedel thyroiditis)?

 

What causes fibrous thyroiditis?

 

Thyroid tissue is replaced by collagen fibers and undergoes fibrosis.

 

unknown

7

 

How is fibrous thyroiditis treated?

 

What complications can be seen in fibrous thyroiditis?

 

prednisone or surgery in some cases

 

tracheal compression, fibrous infiltration of surrounding structures

8

 

What causes Grave's disease?

 

What is seen on histology and what is seen grossly?

 

Antibodies activate the TSH receptor on the thyroid, causing hyperthyroidism.  

 

Grossly, the thyroid will look larger.  On histology, there will be scalloped colloid and irregular follicles.  

9

 

Very generally, what is a goiter?

 

What can cause a goiter?

 

An enlargment of the thyroid gland

 

Iodine deficiency (most common cause world wide)

Graves disease (most common in US)

Cyanide poisoning

10

 

What does a goiter look like on histology?

 

What is the long term result of a goiter?

 

Variably sized follicles lined by columnar cells, with lots of colloid

 

With time, the goiter can degenerate into a cyst, fibrosis, calcification, or hemorrhage

11

A patient comes into the clinic and had a nodule on her thyroid.

 

What is the likelihood that it is cancer?

 

What test should be done?

 

Very slim; carcinomas are >1% of nodules.  It is more likely a cyst, hyperplasia, or benign tumor.  

 

Fine needle aspiration should be done; it is useful for diganosing most carcinomas, but can not differentiate follicular adenoma from follicular carcinoma. 

12

 

Will follicular adenoma produce thyroid hormone?

 

Will follicular adenoma progress to carcinoma?

 

What does a follicular adenoma look like on histology?

 

Probably not, but some do

 

No, it is completely benign 

 

It is surrounded by a fibrous capsule and will not invade surrounding tissue. 

13

 

How common is thyroid carcinoma?

 

What is the biggest risk factor?

 

Very rare; 1.5% of cancers

 

Exposure to ionizing radiation (huge spikes in thyroid cancer after cherynoble)

14

 

What are the four different types of thyroid carcinoma?

 

What mutations are seen in each type?

  1. Follicular
    • RAS mutation- constituitive growth
  2. Papillary 
    • BRAF/RAS- constituitive growth
  3. Medullary
    • RET- activation of neuroendocrine receptor 
  4. Anaplastic
    • P53 mutation- cell can noot be killed, very aggressive tumor

 

15

 

Who is most likely to get papillary thyroid cancer?

 

What might indicate a less favorable prognosis?

 

Young adults 20-40

 

patient older than 40

tumor larger than 5cm

extrathyroid extension

metastasis to bone

16

 

What does papillary carcinoma look like on histology?

 

 

  • Clear nuclei (orphan annie eyes)
  • intranuclear inclusions
  • intranuclear grooves

 

17

 

Who is most likely to get follicular thyroid carcinoma?

 

What are signs of a less favorable prognosis?

 

patients ago 40-50

 

more advanced stage

18

 

What does follicular carcinoma look like on histology?

 

Very well-differentiated; almost impossible to differentiate from follicular adenoma

 

However, capsular invasion or vascular invasion indicate follicular carcinoma.  

19

 

What is different between papillary and follicular carcinoma metastasis?

 

 

 

  • Spread
    • Papillary spreads via the lymphatics while follicular spreads vascularly
  • Prognosis
    • papillary carcinoma typically presents with metastasis, but survival is not affected; follicular survival is largely dependent on stage

20

Medullary Carcinoma

 

Why does the mutation make sense?

 

What percentage of these tumors are sporadic and what percentage are due to a germline mutation?

 

 

RET is a signalling protein for neuroendocrine cells and medullary carcinoma affect parafollicular C cells.

 

80% are sporadic

20% are due to MEN-2

(on the brightside, you'd be protected against hirschprung's with this mutation)

 

 

21

 

What is seen on histology in a medullary carcinoma of the thyroid?

 

Nests of neuroendocrine cells

 

amyloid stroma- this is highly indicative and will usually be stained with congo red

 

Calcitonin +

Thyroglobulin -

22

 

Who is most likely to get anaplastic thyroid carcinoma?

 

What is the prognosis?

 

What is seen on histology?

 

older adults (mean age of 65)

 

very bad; virtually 100% mortality

 

Nasty stuff, very ugly, very pleomorphic

23

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