Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MBBS II ERS > L09 – Autoimmune Thyroid Disorders and Thyroiditis > Flashcards

L09 – Autoimmune Thyroid Disorders and Thyroiditis Flashcards

(69 cards)

Start Studying
1
Q

3 common causes of hyperthyroidism?

A

 Graves’ disease
 Toxic multinodular goiter
 Toxic adenoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

2 causes of Transient hyperthyroidism?

A

 Initial phase of Hashimoto thyroiditis

 Subacute granulomatous thyroiditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List symptoms of hyperthyroidism? think increased sympathetic activity

A

 Irritability, nervousness/anxiety  Heat intolerance, excessive sweating warm flushed skin
 Tremors
 Palpitations, tachycardia
 Weight loss despite increase in appetite
 Hypermotility of intestines&raquo_space; steatorrhea
 Proptosis (Graves’ disease)
 Fatigue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List some primary, congenital causes of Hypothyroidism?

A

 Thyroid dysgenesis
 Dyshormonogenetic goiter
 Enzyme defects in thyroid hormone synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Most common cause of hypothyroidism?

A

Autoimmune: Hashimoto thyroiditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List some iatrogenic causes of hypothyroidism?

A

surgical / radiation-induced ablation

Drug-induced, e.g.: lithium, iodides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What diseases cause secondary hypothyroidism?

A

hypothalamic / pituitary diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List some clinical manifestations of hypothyroidism in children?

A

cretinism:

 Severe mental retardation
 Short stature
 Coarse facial features, protruding tongue
 Umbilical hernia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

List some clinical manifestations of hypothyroidism in older children and adults? think decreased sympathetic activity

A
  • Constipation
  • Cool, pale skin with decreased sweating
  • Fatigue, reduced exercise capacity and weak pulse
  • Apathy
  • Mental sluggishness
  • Non-pitting peripheral edema
  • Broad and coarse facial features with enlargement of tongue and deepening voice
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain how hypothyroidism causes reduced cardiac outut?

A

Low thyroid hormones = decreased transcription of Sarcolemmal genes (Ca-ATPase)/ SERCA = decreased cardiac output efficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List the 3 autoantibodies made in Grave’s disease?

A
  1. Thyroid-stimulating immunoglobulins (TSI) = stimulatory *****
  2. Thyroid growth-stimulating immunoglobulins (TGSI) = stimulatory
  3. TSH-binding inhibitor immunoglobulins (TBII) = inhibitory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain why some patients with Grave’s can exp. hypothyroidism?

A

Stimulating and inhibiting immunoglobulins may coexist

> > spontaneously develop episodes of hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Compare the effects of TSI and Thyroid growth stimulating Ab?

A

TSI = IgG binds to TSH receptor&raquo_space; mimics TSH&raquo_space; Stimulate adenyl cyclase&raquo_space; release thyroid hormones

TGSI = also targets TSH&raquo_space; proliferation of thyroid follicular epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Effect of TSH-binding inhibitor Ab?

A

Prevent TSH from binding to its receptor on thyroid follicular epithelial cells = inhibit thyroid cell function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

3 clinical presentation signatures of Grave’s?

A
  1. Diffuse symmetrical enlargement of gland (goiter)
  2. thyrotoxicosis and related symptoms
  3. infiltrative ophthalmopathy/ Exophthalmos
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the gross changes to the thyroid gland in Grave’s disease? P/E result?

A
  • Diffuse symmetrical enlargement: congested/ haemorrhagic
  • Prominent vascularity, increased blood flow = Bruit
  • Soft, Spongy, without well- defined nodules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

3 pathological changes associated with infiltrative ophthalmopathy?

A
  1. Increase in inflammatory cells (mainly T cells)
  2. Accumulation of extracellular matrix = myxoid ground substance
  3. Increase in number of adipocytes (fatty infiltration)

> > > edema of retro-orbital tissue and extraocular muscles
displace eye forward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Complications of infiltrative opthalmopathy?

A
  • Opthalmoplegia: extraocular muscles weaken over time

- Exophthalmos > corneal injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Pathological changes seen in infiltrative dermatopathy?

A

Pretibial Myxedema:
- Dermis expanded due to Mucopolysaccharide deposits on skin over shins ***
» Pigmented nodules with Orange peel texture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Epidemiology and genetic mutations of Grave’s disease?

A
  • Women predominant, 20-40
  • HLA- DR9 in Chinese
  • Polymorphism of Inhibitory T-cell receptor CTLA-4 & Tyrosine phosphatase PTPN22
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Thyroid hormone level changes in Grave’s?

A

 Elevated serum free T4, T3
 Suppressed serum TSH
 Serum autoantibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Radiological test for Grave’s?

A

I-123 scan: radioactive iodine uptake is diffusely increased

Ultrasound or CT scans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the histological appearance of thyroid gland in Grave’s disease?

A
  • Small thyroid follicles with PAPILLARY INFOLDINGS (loss of colloid content)
  • Follicular cell hyperplasia
  • SCALLOPING of colloid (pushed to periphery of follicles)
  • Patchy LYMPHOCYTIC infiltration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Treatment options for Grave’s disease?

A

1)
i) Anti-thyroid drugs (e.g. methimazole, propylthiouracil, carbimazole)
ii) β-blockers e.g. propranolol = control/relieve the cardiac symptoms)

2) Nonradioactive iodine (inhibit T3/T4 release and peripheral conversion)
3) Refractory = Radioactive Iodine Ablation + lifelong T4 supplement
4) Refractory = Thyroidectomy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Ddx of Grave's disease? *think about the metrics and P/E exam* (5)
Adenomatous nodules (nodular hyperplasia) Toxic multinodular goiter (hyperthyroidism w/o autoAb) Early Hashimoto thyroiditis = ‘Hashitoxicosis’ PAPILLARY thyroid CARCINOMA Dyshormonogenetic goiter (inherited defect in T4/T3 metaolism)
26
Complications of treatments for Grave's disease?
Radioactive iodine = follicular destruction, fibrosis, and dystrophic calcification = hypothyroidism Anti-thyroid drugs = hyperplastic changes (degenerative, not malignant) + loss of colloid
27
Which condition resembles Grave's histologically but has opposite thyroid hormone levels?
Dyshormonogenetic goiter | Low T3/T4 but high TSH = opposite to Grave's
28
Name the most common carcinoma of the thyroid and list 3 histological features?
Papillary thyroid carcinoma Papillary architecture cells with nuclear grooves + pseudonuclear inclusions
29
Ddx Grave's from Toxic multinodular goiter?
Toxic Multinodular goiter: - Also Hyperthyroidism - NO Auto-Ab - Multinodular vs no defined nodules in Grave's - Abundant colloid vs reduced colloid in Grave's
30
Ddx Adenomatous nodules and Grave's?
Adenomatous nodules: - No AutoAb - Multinodular asymmetrical goiter* vs symmetrical, diffuse goitre in Grave's - Abundant colloid vs reduced colloid in Grave's
31
Pathogenesis of Hashimoto thyroiditis?
- Anti-thyroglobulin autoAb + Anti-thyroid peroxidase microsomal antibodies bind to thyroid antigens >> ADCC + Activation of CD4 Th1 >> Progressive depletion/ fibrosis of thyroid epithelial cells
32
Clinical presentation of Hashimoto's?
- Painless, symmetrical, diffusely enlarged thyroid - Hypothyroidism symptoms - Transient thyrotoxicosis (Hashitoxicosis)
33
Hashimoto's predispose to development of which cancer?
primary thyroid non-Hodgkin lymphomas
34
Which conditions are associated with hashimoto's?
Other autoimmune diseases: Pernicious anemia Type II diabetes mellitus SLE Thrombotic thrombocytopenic purpura
35
Epidemiology and genetic predisposition of Hashimoto's
Women predom, 45-65 HLA-DR3 and -DR5 CTLA4 polymorphism High familial clustering
36
Which dietary deficiencies can lead to Hashimoto's?
iodine, selenium deficiency
37
Thyroid hormone levels in Hashimoto's?
 Suppressed T4 / T3  Elevated TSH
38
Which Ab in Hashimoto's is more specific?
 Antithyroglobulin antibody in >60% of patients  Antithyroid microsomal antibodies** in 95% of patients
39
Gross changes to thyroid in Hashimoto's?
symmetrically enlarged (2-3 times the size of normal) Bosselated (with protuberance)/ irregular surface Prominent pyramidal lobe
40
Overall changes to the thyroid parenchyma in Hashimoto's?
- Accentuated LOBULATION - Diffuse lymphoplasmacytic/ Chronic inflammatory cell infiltration - FIBROSIS of parenchyma = yellow
41
Typical Histological changes to thyroid in Hashimoto's?
- REACTIVE LYMPHOID follicles *** with prominent germinal center formation - ATROPHIC*** THYROID follicles - Follicular cells show prominent ***Hürthle cell change ***
42
Describe Hürthle cell changes?
Cellular enlargement Increased number of mitochondria eosinophilic, granular cytoplasm
43
Histological changes seen in Fibrotic variant of Hashimotos?
Prominent acellular, KELOID- LIKE FIBROSIS **Does NOT extend beyond gland = Ddx from Riedel's Thyroiditis** FOLLICULAR ATROPHY Chronic inflammatory cell infiltrate
44
Treatment options for Hashimotos?
- Levothyroxine (lifelong) - immunosuppressive therapy (e.g. steroids) - Unresponsive/ malignant/ compressive = Surgery
45
DDx of Hashimoto thyroiditis?
- Lymphocytic thyroiditis - Riedel thyroiditis/ IgG4- related thyroiditis - Papillary thyroid carcinoma - Lymphoma
46
Pathogenesis of subacute lymphocytic thyroiditis?
Initial inflammation and destruction of thyroid follicles = 4-8 weeks thyrotoxicosis Thyroid depleted of colloid = hypothyroidism after 2 months
47
2 theories for pathogenesis of Riedel's thyroiditis?
1) Anti-thyroid antibodies >> autoimmune | 2) SLE/ Scleroderma >> IgG4-related sclerosing disease >> dense thyroid fibrosis
48
Clinical presentation of Riedel's thyroiditis?
- Usually EUTHYROID, subsequent hypothyroidism - ‘Sudden’ onset of enlarged, painless neck mass - dysphagia, dyspnoea, and stridor - Non-tender, HARD GLAND on palpation
49
Explain why Riedel's thyroiditis cause dysphonea?
Fibrosis of thyroid cause compression and excasement of recurrent laryngeal nerve
50
Thyroid hormone levels in Riedel thyroiditis? Antibodies?
anti-thyroglobulin antibodies and anti microsomal antibodies (similar to Hashimoto's) Usually euthyroid, 30-40% develop subsequent hypothyroidism
51
Gross morphology of thyroid in Reidel thyroiditis?
- Avascular, woody, tan-grey with loss of lobulation - Extensive fibrosis HARD GLAND
52
Histological appearance of Riedel's thyroiditis?
Similar to Fibrotic Variant of Hashimotos - KELOID-LIKE FIBROSIS replace follicles - Extension of fibrosclerotic process to extrathyroidal soft tissue and parathyroid gland **Ddx from Fibrotic variant of Hashimoto** - lymphocytes, plasma cells infiltration
53
Treatment options for Riedel thyroiditis?
steroids, tamoxifen Hypothyroid = hormone replacement Systemic fibrosis = Mycophenolate mofetil Compressive symptoms = Surgery
54
Name 2 conditions morphologically similar to Riedel thyroiditis?
Fibrotic Variant of Hashimoto's** IgG4-related thyroiditis Only Riedel's thyroiditis fibrotic process extend beyond gland
55
Gross morphology, histology of IgG4-related thyroiditis?
WHITE with lobulations + fibrotic STROMAL FIBROSIS + FOLLICULAR ATROPHY lymphocytes, plasma cells infiltration **Fibrosis does NOT extend to extrathyroid tissue** Ddx Riedel's
56
Dx of IgG4- related thyroiditis?
↑ IgG4+/IgG+ plasma cells (>40%) histologically
57
Epidemiology of Subacute granulomatous thyroiditis?
Women predom, 30-50
58
Causes of Subacute granulomatous thyroiditis (de Quervain’s thyroiditis)?
preceding URTI >> inflammatory rxn After anti-viral therapy (interferon) (rare)
59
List some viral infectons that precede Subacute granulomatous thyroiditis?
Measles, influenza, adenovirus, Epstein-Barr virus, Coxsackie virus, mumps, HIV, H1N1
60
Symptoms of Subacute granulomatous thyroidits?
6-8 weeks: neck pain, sore throat and difficulty in swallowing, low-grade fever, malaise initial ‘thyroid storm’ followed by hypothyroidism Enlarged, tender thyroid
61
Thyroid levels in subacute granulomatous thyroiditis?
Initial - High T3/T4, low TSH (Thyroid storm) Mid-phase = hypothyroidism Late = euthyroid
62
Gross appearance of subacute granulomatous thyroiditis?
Firm, glossy, intact capsule | unilaterally or bilaterally enlarged
63
Histology of subacute granulomatous thyroiditis?
Disruption of thyroid follicles, extravasation of colloid MULTINUCLEATED GIANT CELLS to engulf colloid
64
DDx of subacute granulomatous thyroiditis?
Other foreign body type granulomatous reactions: - Mycobacterium - Fungus - Sarcoidosis
65
List some pathogens that can cause infectious thyroiditis?
Streptococcus haemolyticus, staphylococcus aureus, pneumococcus (actinmyces, candida spp., pneumocystis jirovecii)
66
Pathogenesis of infective thyroiditis?
NEUTROPHILIC infiltration and cytotoxicity ABSCESS formation and follicle extravasation >>> Graulomatous reaction
67
Histological appearance of radiological thyroiditis? (e.g. after radiotherapy for head and neck squamous cell carcinoma)
 DISRUPTED ARCHITECTURE  Parenchymal FIBROSIS, vascular sclerosis  Chronic (lymphocytic) inflammation
68
What is the cause and reaction of palpation thyroiditis?
vigorous clinical palpation of the thyroid Colloid is leaked from traumatized follicles into the surrounding stroma >> foreign body type granulomatous reaction
69
List some drugs that can induce thyroiditis? Effect on thyroid activity?
Iodide, lithium, anticonvulsants, amiodarone >> Painless enlargement of thyroid gland >> Hyper- / hypo-thyroidism

MBBS II ERS (37 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions