Thyroiditis and Thyroid Cancer Flashcards Preview

Gen Med: Ednocrine > Thyroiditis and Thyroid Cancer > Flashcards

Flashcards in Thyroiditis and Thyroid Cancer Deck (38):
1

Define thyroiditis

1. Inflammation of thyroid gland
2. Caused by an attack on the thyroid, resulting in inflammation & damage to the thyroid cells

2

What are the types of thyroiditis?

1. Hashimoto’s Thyroiditis
2. Painful Subacute Thyroiditis
3. Nonpainful Subacute Thyroiditis
4. Rare Thyroiditis
A. Riedel's
B. Suppurative

3

What is the most common form of thyroiditis?

Hashimoto’s Thyroiditis

4

What are the painful subacute thyroiditis?

1. De Quervain's thyroiditis *
2. Traumatic or palpation induced thyroiditis*
3. Radiation-induced thyroiditis*
A. 2° to RAI in Graves’ Dz Tx

5

What are the nonpainful subacute thyroiditis?

1. Postpartum thyroiditis
2. Drug-induced thyroiditis
A. Amiodarone (37% iodine)

6

What are the rare thryoiditises?

1. Riedel's thyroiditis
A. Slow enlarging mass mistaken for CA
2. Suppurative or Infectious thyroiditis*
A. Acute or chronic
B. More common in children

7

define subacute thyroiditis

Self-limiting inflammation of thyroid

8

What causes subacute thyroiditis? What is the progression?

1. Usually 2° to a virus
A. Initially hyperthyroid labs w/ or w/o hyperthyroid sx’s
B. Followed by hypothyroid labs & sx’s
C. Then euthyroid state
D. Phases occur over 6-9 mos

9

What are the characteristics of postpartum thyroiditis?

1. Painless subacute lymphocytic thyroiditis ( ↑, ↓, → thyroid)
2. Results from modifications to immune system during pregnancy
3. Type I DM 3x greater risk of development
4. Considered variant of Hashimoto’s thyroiditis

10

What is the progression of postpartum thyroiditis?

1. Normally self-limiting, but if anti-Thyroid Ab are present (20%), ↑ risk of permanent hypothyroidism
2. Painless thyroiditis occurs w/in 1 yr after childbirth or TOP (termination of pregnancy)
A. Sx’s can be subtle & underdiagnosed

11

What is De Quervain's thyroiditis also called?

1. Painful Subacute Granulomatous Thyroiditis
2.Giant Cell Thyroiditis

12

What are the characteristics of De Quervain's thyroiditis?

1. Acute painful thyroiditis, often w/ dysphagia
2. F > M
3. 40’s - 50’s

13

What are the sxs of De Quervain's thyroiditis?

1. Hx viral URI (2-8 wks prior)
2. Low-grade fever & fatigue
3. Neck pain, malaise & myalgias
4. Painful goiter
A. Radiates to jaw/ear
B. Aggravated by swallowing/turning head

14

What are the diagnostic studies for subacute thyroidits?

1. Free T4, TSH
A. Results depend on stage of presentation of pt
2. ↑ ESR
3. ↑ WBC w/ L shift
A. Subacute & suppurative thyroiditis
4. ↑ Automicrosomal Ab
A. 50-80% in postpartum thyroiditis
5. ↑Serum thyroglobulin levels (nonspecific)
A. Painful subacute & postpartum thyroiditis

6. Color-flow Doppler U/S
A. Thyroiditis normal or ↓ vascularity vs ↑ in Graves’ Dz

7. ↓ Radioactive Iodine (RAI) uptake vs ↑ uptake in Graves’ Dz

15

How is subacute thyroiditis treated?

1. Postpartum thyroiditis
A. Majority do not need Tx but need to monitor FT4 and TSH
2. B-blockers
A. PRN hyperthyroid sx’s
3. NSAID’s (first) or Corticosteroids (refractory): treat inflammation
A. Painful thyroiditis
4. IV Antibx & Abscess I&D if needed in suppurative
5. Thyroid hormone replacement
A. Levothyroxine qd if permanent
B. Short term Tx if hypothyroid sx’s

16

What pt education needs to occur after subacute thyroiditis?

1. Patient follow up and monitoring
A. Free T4
B. TSH
C. ESR
2. May result in
A. Permanent hypothyroidism
B. Future development of hypothyroidism
3. Postpartum Thyroiditis tends to recur in subsequent pregnancies

17

What are the types of thyroid cancer?

1. Papillary CA
A. Unencapsulated & may be partially cystic
2. Follicular CA
3. Medullary
4. Anaplastic (undifferentiated) CA

18

What are the epidemiologic factors for thyroid cancer?

1. More common in areas of world that lack iodine in diet
2. F>M 3:1
3. Risk ↑ w/ age
4. Usually solitary nodule
A. < 5% of thyroid nodules are malignant

19

What are the risk factors for thyroid cancer?

1. Childhood irradiation
A. Cancer occurring 20-25 yr later
2. FH of thyroid CA in 1st degree relative
3. Occupational & environmental exposures
4. Hepatitis-C-related chronic hepatitis
5. Increased parity & late age at 1st pregnancy

20

What factors increase the likelihood of malignancy?

1. < 20 yr or > 70 yr
2. Male w/ nodule is cancer until proven otherwise
3. Sx’s of dysphagia, hoarseness
A. Recurrent laryngeal N. irritation
4. History of irradiation
A. Lymphoma Tx, nuclear disaster exposure
5. Prior h/o thyroid cancer or polyps (Gardner’s syndrome)
6. Hx of thyroiditis
7. Cervical lymphadenopathy
8. Firm or hard immobile, nontender nodule/mass
9. Nodule ↑ size or > 1cm in diameter

21

What factors suggest a benign nodule?

1. FH of autoimmune disease
2. FH of benign thyroid nodule or goiter
3. Hyperthyroidism or hypothyroidism found on lab studies
4. Characteristics of nodule
A. Smooth, soft, mobile, tender

22

What is the mc form of thyroid cancer?

Papillary carcinoma
>70% of thyroid cancer

23

What are the characteristics of papillary carcinoma?

1. Least aggressive form
2. Lymphatic spread
A. 2/3 pulmonary mets
B. 1/4 skeletal mets
C. Rare sites
-Brain, kidneys, liver, adrenals

24

What is the 2nd mc form of thyroid cancer?

Follicular carcinoma

25

What are the characteristics of follicular carcinoma?

1. Older patients
2. Assoc. w/ iodine deficiency
3. More aggressive than Papillary CA
4. Spreads hematogenously w/ distant metastasis
A. Bone (lytic lesions) & lung
B. Less commonly
-Brain, liver, bladder, skin

26

What is Gardener's syndrome?

Thyroid polyps

27

What are the causes of medullary carcinoma?

1. Rare (4%) of thyroid CA
2. 1/3 familial, 1/3 sporadic, 1/3 associated with MEN syndromes

28

What is medullary carcinoma?

1. Neuroendocrine tumor of the parafollicular (C cells) of thyroid gland
2. Solitary nodule w/mets at Dx-common
3. Produces Calcitonin

29

What are MEN syndromes?

1. Multiple Endocrine Neoplasia Type 2-MEN 2
A. Disorders assoc. w/ tumors (benign or malignant) of the endocrine system
B. Pheochromocytoma in 50% of cases
3. Family members of patients diagnosed with Medullary Carcinoma

30

What is anaplastic carcinoma?

Rapidly enlarging, painful nodule

31

What are the characteristics of anaplastic carcinoma?

Very rare (2%)
1. Aggressive
A. Regional or distant mets @ initial diagnosis in 90% of cases
B. Regional
-Perithyroidal fat & muscle, lymph nodes, larynx, trachea, esophagus, tonsils, great vessels of the neck & mediastinum
C. Distant
-Lungs, bone, brain (rare: skin, liver, kidneys, pancreas, heart, adrenals)
2. Elderly patients
A. Mean age 65 yr

32

How is anaplastic carcinoma treated?

1. No curative therapy exists if mets
A. Chemo/RadioTx if localized
2. Generally fatal w/in 1 yr

33

What are the DDX of thyroid nodules?

1. Benign nodules
A. Cysts
B. Toxic multinodular goiter
C. Toxic adenoma
D. Hashimoto’s thyroiditis
2. Thyroid cancer
Metastatic differentiated thyroid Ca
A. 20 – 30% pts w/ anaplastic thyroid CA have coexisting differentiated thyroid cancer
3. Thyroid lymphoma

34

What are the dx studies for thyroid cancer?

1. Thyroid USN
2. FNA & Biopsy
A. U/S guided
3. TSH, FT3, FT4
A. Typically normal
4. Serum calcitonin, carcinoembryonic antigen (CEA)
A. ↑ in medullary CA
5. Technetium 99 nuclear imaging

PET scan if indicated
Anaplastic CA

35

What are the results of Technetium 99 nuclear imaging?

A. Hot nodule: rarely malignant (Benign)
B. Warm nodule: benign or malignant
C. Cold nodule: worry about malignancy

36

When is a PET scna indicated for thyroid cancer?

Anaplastic cancer

37

What is the treatment for thyroid cancer?

1. Total Thyroidectomy
A. Include lymph node dissection if medullary CA
2. Radioactive Iodine-131 used w/ papillary or follicular thyroid CA
A. Ablates residual thyroid tissue after surgery
B. Treats thyroid CA
3. Thyroid hormone replacement
A. TSH suppression
- Minimize recurrence
- Tx hypothyroidism

38

When is external irradiation indicated for thyroid cancer?

1. Unresectable CA
2. Recurrence after resection
3. Pain relief from bone mets