Thyroid Flashcards

1
Q

Congenital Thyroid Disease

A

 Linryology gual thyroid
 Ectopic thyroid tissue
 Thyroglossal cyst

Embryology
Thyroid migrates from its origin at the foramen caecum at the base of the tongue.
 Passes behind the hyoid bone
 Lies anterior to 3rd-4th tracheal rings in the
pretracheal fascia.

Leaves behind the thyroglossal cyst which atrophies
 Persistence → thyroglossal cyst

Ectopic thyroid tissue can be found anywhere along this
descent

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

Goitre Differential

A
Diffuse
Simple colloid goitre
 Endemic: iodine deficiency
 Sporadic: autoimmune, hereditary, goitrogens
(e.g. sulphonylureas)

Graves’

Thyroiditis
 Hashimoto’s
 De Quervain’s
 Subacute lymphocytic (e.g. post-partum)

(multinodular goitre c¯ nodules too small to palpate)

Multinodular
 Multinodular colloid goitre (commonest)
 Multiple cysts
 Multiple adenomas

Solitary nodule
 Dominant nodule in multinodular goitre
 Adenoma (hot or cold)
 Cyst
 Malignancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Thyroid lump Ix

A

Bloods
 TFTs: TSH, fT3, fT4
 Other: FBC, Ca2+, LFTs, ESR
 Antibodies: anti-TPO, TSH

Imaging
 CXR: goitres and mets
 High resolution US
 CT
 Radionucleotide (Tc or I) scan (hot vs. cold)

Histology or cytology
 FNAC (can’t distinguish adenoma vs. follicular Ca)
 Biopsy

Laryngoscopy
 Important pre-op to assess vocal cords

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

Simple goitre

A
Diffuse painless goitre
Mass effects 
- dysphagia
- stridor
- SVC obstruction 
usually euthyroid, may be hypothyroid 
Cause 
Endemic - iodine deficiency 
Sporadic 
- autoimmune
- goitrogens (sulphonylureas)
- hereditary (dyshormogenic)

Mx
thyroxine
Total or subtotal thyroidectomy if pressure Sx

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

Multinodular Goitre

A

Evolves from long-standing simple goitre
mass effects
Euthyroid (or hyperthyroid)

Causes - same as simple goitre

Mx

Thyroxine
Total or subtotal thyroidectomy if pressure Sx

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

Plummer’s Toxic Multinodular Goitre

A

Multinodular goitre
Thyrotoxicosis
Uneven iodine uptake with hot nodule

Cause
Autonomous nodule develops on background multinodular goitre

Mx
Carbimazole
radioiodine
total or subtotal thyroidectomy

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

Grave’s Disease

A
Diffuse goitre w bruit 
Opthalmopathy 
Dermopathy 
Thyrotoxicosis
Assw other AI disease (T1DM, PA) 
^uptake on radionucleotide scan

Cause - AI (T2 hypersensitivity) - anti-TSH

Mx
Propanolol 
Carbimazole 
Radioiodine 
thyroidectomy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hashimoto’s Thyroiditis

A

Diffuse goitre - may have transient thyrotoxicosis > hypothyroidism
Assw other AI Disease (T1DM, PA)

Cause - Autoimmune T2, T4 hypersensitivity
- AntiTPO, anti-Tg

Mx
levothyroxine

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

de Quervain’s

A

Diffuse painful goitre
preceding viral URTI common
Thyrotoxicosis > hypo> eu
decreased iodine uptake

Causes - Viral - coxackie common
AI

Mx - self-limiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Subacute lymphocytic Thyroid disease

A

Diffuse painful goitre
may occur post-partum
thyrotoxicosis > hypo > eu

autoimune

conservative Mx

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

Riedel’s thyroiditis

A

Firm fixed irregular thyroid mass
mass effects
assw retroperitoneal fibrosis

Cause - AI fibrosis

Mx - conservative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Follicular adenoma

A

Single thyroid nodule +/- thyrotoxicosis (majority are cold)

May get pressure Sx

Mx - hemithyroidectomy

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

Thyroid cysts

A

solitary thyroid nodule
ASx or pressure Sx
can > localised pain due to cyst bleed

Mx - aspiration or excision

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

Follicular adenoma

A

single thyroid nodule
+/- thyrotoxicosis (majority are cold)
May get pressure Sx

Mx - hemithyroidectomy

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

Malignant Thyroid Disease

A

Pete fucked many angry ladies

Papillary
Follicular
Medullary Anaplastic
Lymphoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Papillary Thyroid Cancer

A

80%
assw irradiation
20-40

Follicular cells
Tg tumour marker

Spread - nodes + lung - JDG node = lateral aberrant thyroid
often multifocal

Mx
- total thyroidectomy +/- node excision +/- radioiodine
T4 to suppress TSH
>95% 10 years

17
Q

Follicular Thyroid Cancer

A

10% 40-60
F>M 3:1

Follicular cells
Tg tumour marker

Spread - blood > bone + lungs

Mx - total thyroidectomy + T4 suppression + radioiodine

> 95% 10 years

18
Q

Medullary Thyroid Cancer

A

5%
30% familial (eg MEN2) >60

Parafollicular C-cells
CEA and calcitonin markers

Mx - do phaeo screen pre-op
Thyroidectomy, node clearance, consider radiotherapy

19
Q

Anaplastic Thyroid Cancer

A

Rare >60
F>M 3:1

Undifferentiated follicular cells

Spread - rapid growth, aggressive local LN + blood

Mx - usually palliative, may try thyroidectomy + radiotherapy

<1% 10 years

20
Q

Lymphoma (thyroid)

A

5%

MALToma in Hashi’s
Lymphocytes

Mx chemoradiotherapy

21
Q

Thyroid Cancer Presentation

A
Non-functional (cold)
Painless neck mass
Cervical mets
Compression Sx 
- dysphagia
- stridor
- SVC obstruction
22
Q

Thyroid cancer RF for malignancy in thyroid Nodules

A
Solitary
solid
younger 
male 
cold 
radiation exposure
23
Q

Thyroid surgery Indications

A

5Ms

mechanical obstruction
malignancy
marred beauty (cosmetic)
medical Rx failure - thyrotoxicosis 
Mediastinal extension - can't monitor changes
24
Q

Practicalities of thyroid surgery

A

Render euthyroid pre-op

  • stop 10 days prior to surgery (they ^ vascularity)
  • alternatively just give propanolol

check for phaeo pre-op in medullary carcinoma

Laryngoscopy - check vocal cords pre and post-op

Procedure - collar incision

25
Q

Complications of thyroid surgery

early

A

Early

Reactionary haemorrhage → haematoma (<1%)
 Can → airway obstruction.
 Call anaesthetist and remove wound clips
 Evacuate haematoma and re-explore wound

Laryngeal Oedema
 Damage during intubation or surgical
manipulation
 Can → airway obstruction

Recurrent Laryngeal nerve palsy (0.5%)
 Right RLN more common (oblique ascent)
 Damage to one → hoarse voice
 Damage to both → obstruction needing
tracheostomy 

Hypocalcaemia
 Parathyroid dysfunction but may be permanent if parathyroids removed

Presents @ 24-48hrs
 Tingling in fingers and lips
 Wheeze / stridor → airway obstruction
 Chvostek’s and Trousseau’s

Rx: 10ml 10% Ca gluconate IV

Thyroid Storm
- Severe Hyperthyroidism
- Rx - propanolol, antithyroid drugs, Lugol’s iodine
+ hydrocortisone sodium succinate

26
Q

Complications of thyroid surgery

late

A

Hypothyroidism
recurrent hyperthyroidism
keloid scar