T3 - L1 Diseases of the endocrine system Flashcards
(121 cards)
1
Q
What is the difference between endocrine, paracrine and autocrine?
A
endocrine = secrete into blood stream and act systemically
paracrine = act locally
autocrine = affects the cell secreting the protein
2
Q
Where is the pituitary gland situated?
A
in the sella turcica beneath the hypothalamus
3
Q
What are the anterior and posterior parts of the pituitary also called?
A
anterior lobe (75%) = adenohypophysis (formed by outpouching of oral cavity)
posterior lobe (25%) = neuropophysis (formed by downgrowth of hypothalamus)
4
Q
What are the causes of anterior pituitary hypofunction?
A
- tumours (non-secretory adenoma, metastatic carcinoma)
- trauma
- infection
- inflammation (granulomatous, autoimmune, other infections)
- iatrogenic
5
Q
Describe the features of primary pituitary tumours
A
- vast majority are adenomas and benign
- may be derived from any hormone-producing cell
- effect hormone being produced
- local effects due to pressure on optic chiasma or adjacent pituitary
6
Q
Name the 3 types of anterior pituitary adenoma
A
- prolactinoma
- growth hormone secreting
- ACTH secreting
7
Q
What is the commonest anterior pituitary adenoma?
A
Prolactinoma
8
Q
What do you get in prolactinoma pituitary adenomas?
A
Galactorrhoea and menstrual disturbance
9
Q
What is galactorrhoea?
A
Excessive or inappropriate production of milk
10
Q
What do you get in growth-hormone secreting pituitary adenomas?
A
Gigantism in children, acromegaly in adults
NB: caused by an increased production of growth hormone/ somatotropin
11
Q
Describe the anatomy of the thyroid
A
- Bilobed
- joined by isthmus
- encased in thin fibrous capsule
- located at level 5th/6th/7th vertebra
- anterior neck, close to trachea
12
Q
Describe the anatomic relationships of the thyroid
A
- abuts thyroid cartilage of larynx
- recurrent laryngeal nerve located in tracheo-oesophgeal groove, close to posterior aspects of lateral lobes
13
Q
What is cretinism?
A
Severely stunted physical and mental growth due to untreated congenital deficiency of thyroid hormones (congenital hypothyroidism) usually due to maternal hypothyroidism
14
Q
What is the most common type of thyroid ectopia?
A
Lingual thyroid (usually at base of tongue)
15
Q
What occurs in most patients with lingual thyroid?
A
- over 75% have no other thyroid tissue
- 70% have hypothyroid
- 10% have cretinism
16
Q
Other than lingual thyroid, what are the other possible sites of ectopic thyroid?
A
- sella turcica
- larynx
- trachea
- aortic arch
- oesophagus
- heart
- pericardium
- liver
- gall bladder
- pancreas
- vagina
17
Q
Why do thyroglossal duct cysts occur?
A
Persistent track representing the embryological migratory path of thyroid anlage in the anterior neck
18
Q
Who do thyroglossal duct cysts occur in?
A
- most common in children and young adults
- 7% of adults
19
Q
What is the treatment for thyroglossal duct cysts?
A
Sistrunk procedure (with 4-6% recurrence rate)
20
Q
Where are the majority (75%) of thyroglossal duct cysts?
A
Anterior midline of neck or immediately below hyoid bone
- asymptomatic midline neck mass
21
Q
What is acute thyroiditis?
A
Acute inflammation of the thyroid parenchyma associated with local or systemic viral, bacterial or fungal infection
22
Q
Most cases of acute thyroiditis are due to what?
A
Generalised sepsis
23
Q
What are the symptoms of acute thyroiditis?
A
- fever
- chills
- malaise
- pain
- swelling of anterior neck
24
Q
What does the prognosis of acute thyroiditis relate to?
A
The underlying condition
25
What is palpation thyroiditis?
Microscopic granulomatous foci centres on thyroid follicles - secondary to rupture of thyroid follicles due to palpation or surgery
26
Patients with palpation thyroiditis almost always have what?
A thyroid nodule
27
What is Riedel's thyroiditis?
A rare fibrosing form of chronic thyroiditis
- benign self-limited disease
- may be mistaken for malignant neoplasm
28
In Riedel's thyroiditis, the fibrosing disorder may also affect where?
- retroperitoneum
- lung
- mediastinum
- biliary tree
- pancreas
- kidney
- subcutis
29
How may patients with Reidel thyroiditis present?
- firm goitre
- dysphagia
- hoarseness
- stridor
30
What is Hashimoto's?
Chronic lymphocytic thyroiditis - autoimmune chronic inflammatory disorder associated with diffuse enlargement and thyroid autoantibodies
31
Who does Hashimoto's occur in?
- females much more common than males
| - peak age at 59 years
32
What do you get in Hashimoto's?
- diffuse enlargement and thyroid autoantibodies.
- serum thyroid antibodies elevated
- lymphocytic infiltration of thyroid parenchyma
- germinal centre formation
33
Is Hashimoto's associated with hypothyroid or hyperthyroid?
Hypothyroid
34
What do patients with Hashimoto's (chronic lymphocytic thyroiditis) have an increased risk of?
- 80-fold increased risk of thyroid lymphoma
| - increased risk of papillary carcinoma of the thyroid
35
What is Grave's disease? (diffuse hyperplasia)
An autoimmune process results in clinical hyperthyroidism and diffuse hyperplasia of the
follicular epithelium.
36
What are the signs and symptoms of Grave's disease? (diffuse hyperplasia)
- hyperthyroidism
- Pretibial myxoedema
- hair loss
- wide-eyed stare or proptosis
- tachycardia
- hyperactive reflexes.
- thyroid diffusely enlarged.
37
What are the hormone changes in Grave's disease (diffuse hyperplasia)?
- T3 and T4 elevated
| - TSH suppressed
38
What are the autoantibodies in Grave's disease?
Thyroid stimulating immunoglobulins
39
What is a multinodular goitre?
Enlargement of thyroid with varying degrees of modularity
| - 1 or more thyroid nodules discovered by patient or doctor
40
Most patient with multi nodular goitre are euthyroid. What does this mean?
Have a normally functioning thyroid gland
41
What symptom may occur with multi nodular goitre?
- tracheal compression or dysphasia may occur with large nodules
- dominant nodule may be mistaken clinically for thyroid carcinoma
42
What is a follicular adenoma?
A benign encapsulated tumour with evidence of follicular cell differentiation
43
is Grave's disease more common in males or females?
- females more than males
44
How does follicular adenoma present?
- painless neck mass, often present for years
- solitary nodule involving only one lobe
- usually cold nodule on radioactive iodine imaging
45
What is the commonest type of papillary carcinoma?
Papillary carcinoma (over 70%)
46
Who does papillary carcinoma affect?
Females 2.5:1
- mean 43 years
47
What is a papillary carcinoma?
A familial, autosomal dominant non-medullary thyroid carcinoma
48
Papillary carcinoma occurs as a result of what?
- radiation exposure
- FAP
- Cowden's syndrome
- therapeutic irradiation
49
What genetic alterations cause papillary carcinoma?
- activation of RET or NTRK1
- RAS mutations
- BRAF V600E mutation
- variety of chromosomal translocations or inversions
- fusion of RET tyrosine kinase regions with constitutively expressed thyroid proteins eg. PTC1 in inv(10)(q11;q21), PTC2 t(10;17)(q11;q21)
50
Describe the macroscopic appearance of papillary carcinoma
- ill-defined, infiltrative
- some encapsulated
- may be cystic
- granular
51
What is hurthle cell carcinoma also referred to as?
oxyphilic cell carcinoma
52
What is primary hyperparathyroidism?
Excessive secretion of parathyroid hormone from one or more glands (PHPT)
53
What is secondary hyperparathyroidism?
Hyperplasia of glands with elevated PTH in response to hypocalcaemia (due to renal insufficiency, malabsorption, vitamin D deficiency etc)
54
What is tertiary hyperparathyroidism?
Adenoma in association with longstanding secondary hyperparathyroidism
55
What are the potential symptoms/complications of PHPT?
- asymptomatic
- arterial hypertension
- psychiatric problems
- hypercalcaemia
- decreased renal function
- osteoporosis
- hyperparathyroid bone disease
- urolithiasis
56
What are the 3 types of PHPT?
- single adenoma (most)
- diffuse chief/clear cell hyperplasia
- carcinoma (1%)
57
What is parathyroid adenoma?
An encapsulated benign neoplasm of parathyroid cells
Single enlarged parathyroid gland; remaining glands suppressed and small.
58
The symptoms of parathyroid adenoma are due to what?
Hypercalcaemia
59
Parathyroid adenoma is associated with which syndromes?
- MEN1 and MEN2 syndrome
- hyperparathyroidism
- jaw tumour syndrome
60
secondary and tertiary parathyroidism is a non-neoplastic increase in which cell mass?
parathyroid parenchymal cell mass within all parathyroid tissue
61
Which group of patients is secondary and territory parathyroidism common in?
Patients with renal failure and on dialysis
62
Secondary and territory parathyroidism have identical pathologic features to what?
Primary hyperplasia
- may be associated with massive gland enlargement
63
What cells does a parathyroid carcinoma derive from?
parathyroid parenchymal cells
64
How is parathyroid carcinoma treated?
Surgery
65
What is the prognosis for parathyroid carcinoma?
50% 10 year survival
66
The symptoms of parathyroid carcinoma are referable to what?
Excess calcium
- indolent with recurrence in about 50%
67
What are the layers of the adrenal glands from the centre of the gland outwards?
- medulla
- reticularis (part of cortex)
- fasciculata (part of cortex)
- glomerulosa (part of cortex)
68
What do the adrenal glands secrete?
- catecholamines
- androgens
- cortisol
- aldosterone
69
What is Addison's disease?
Primary adrenal cortical insufficiency
70
What are the causes of Addison's disease?
- adrenal dysgenesis
- adrenal dysfunction
- autoimmune adrenalitis
- TB
71
What are the clinical features of Addison's disease?
- hyperpigmentation
- postural hypotension
- hyponatraemia
72
How is Addison's disease treated?
Long term steroid replacement
NB: high mortality if not diagnosed
73
What are adrenal cortical nodules?
Benign non-functional nodules of adrenal cortex
74
Adrenal cortical nodules occur more in who?
- elderly
- hypotensive
- diabetic patients
75
What are the symptoms of adrenal cortical nodules?
- asymptomatic
- incidental discovery on radiographic studies
NB: no treatment required
76
What is adrenal cortical adenoma?
Benign neoplastic proliferation of adrenal cortical tissue
77
What are the symptoms of adrenal cortical adenoma?
Symptoms related to endocrine hyperfunction (hypertension, Cushing's syndrome, virilisation)
78
What do aldosterone-producing tumours cause?
Conn's syndrome
79
What do cortisol-producing tumours cause?
Cushing's syndrome
80
What is Conn's syndrome?
Excess production of the hormone aldosterone by the adrenal glands resulting in low renin levels
81
Describe an adrenal cortical adenoma
- unilateral solitary masses
- 2cm, less than 100g
- well-circumscribed yellow/brown nodules
- formed from lipid-filled adrenal cortical cells
82
What are the features of adrenal cortical carcinoma
- malignant counterpart of adrenal adenoma
- symptoms related to hormone excess
- abdominal mass
- prognosis is age and stage dependent
- 5 year survival about 70%
83
What is phaeochromocytoma?
Catecholamine-secreting tumour arising from adrenal medulla
84
What would be elevated in a urine test for phaeochromocytoma?
- urine catecholamine - adrenaline
| - noradrenaline
85
what familial syndromes can cause phaeochomocytoma?
- MEN2a and 2b
- von Recklinghausen's disease
- von Hippel-Lindau disease
86
what clinical/functioning effects do primary pituitary tumours have?
effects the hormone that cell produces
87
what local effects do primary pituitary tumours have?
pressure on optic chiasma or adjacent pituitary
88
where does the anterior lobe of the pituitary gland derive from?
derived from an outpouching of the roof of the pharynx, called Rathke’s pouch
89
what two hormones does the posterior pituitary gland produce?
ADH (responsible for control of blood osmolarity)
Oxytocin (involved in parturition and milk secretion)
90
what is a prolactinoma?
a benign noncancerous tumor of the pituitary gland that produces a hormone called prolactin
91
what is the hormone produced growth-hormone secreting pituitary adenomas called? and what does this result in?
somatotropin
- giantism in children
- acromegaly
92
what is acromegaly?
- Enlargement of the hands, feet, forehead, jaw, and nose, thicker skin, deepening of the voice
- onset: middle age
- cause: too much growth hormone/somatotropin
93
what type of tumour would cause giantism in children?
Growth hormone secreting tumour of the pituitary gland
94
what type of tumour would cause acromegaly in middle aged adults?
Growth hormone secreting tumour of the pituitary gland
95
what is Cushing syndrome?
- due to prolonged exposure to cortisol
- high blood pressure
- abdominal obesity but thin arms and legs
- reddish stretch marks
- fat lump between shoulders
- weak muscles and bones
- ache
- fragile skin that heals poorly,
- irregular menstuartion,
- mood swings,
- headaches
- fatigue.
96
what type of tumour would cause Cushing's syndrome?
ACTH secreting tumour of the anterior pituitary gland
97
what joins the two lobes of the thyroid?
isthmus
98
what level vertebrae will you find the thyroid?
level of
5th, 6th and 7th vertebra
(between the C5 and T1 vertebrae)
99
the thyroid becomes heavier during pregnancy, true or false?
true
average weight is 18g for adult males, 15g for adult females
100
where will you find the pyramidal lobe of the thyroid?
on top of the isthmus
- however it is a variant seen as a third thyroid lobe and is present in 10-30% of the population.
101
which tracheal rings mark the location of the thyroid?
2nd and 3rd tracheal rings
102
what nerves are commonly damaged during thyroid surgery?
recurrent laryngeal (left and right)
103
where is the recurrent laryngeal nerve located in relation to the thyroid?
posteriorly of the tracheoesophageal groove
104
what is the pyramidal lobe a remnant of?
It represents a persistent remnant of the thyroglossal duct
105
what is the Ultimobranchial body?
In humans, the ultimobranchial body is an embryological structure that gives rise to the parafollicular cells of the thyroid gland.
106
what is the most common type of thyroid carcinoma?
papillary carcinoma
107
what hormone does the Glomerulosa layer of the adrenal gland produce?
Glomerulosa: outer layer producing aldosterone
108
what are tumours arising from the glomerulosa layer of the adrenal gland called?
conn's tumour/syndrome
109
what do tumours of the glomerulosa layer of the adrenal gland layer (conn's tumour) cause?
hyperaldosteronism
110
what hormone does the fasciculata layer of the adrenal gland produce?
Fasciculata: thick middle layer producing cortisol
111
Tumours arising from zona fasciculata are the most commonly cause what?
Cushing's syndrome
112
what hormone does the Reticularis layer of the adrenal gland produce?
Reticularis: inner layer producing androgens
113
what hormone does the Adrenal medulla of the adrenal gland produce?
catecholamine
114
what do medullary tumours cause?
increased serum catecholamine (Phaechromocytoma)
115
what is increased serum catecholamine Phaechromocytoma?
Pheochromocytoma (PCC) is a neuroendocrine tumor of the medulla of the adrenal glands (originating in the chromaffin cells), or extra-adrenal chromaffin tissue that failed to involute after birth, that secretes high amounts of catecholamines
116
what care exogenous causes of Cushing's syndrome?
excessive glucocorticoid medication
117
what care endogenous causes of Cushing's syndrome?
- adrenal cortical tumours
- adrenal cortical hyperplasia
- ACTH
secreting pituitary adenoma
118
what tumour is associated with Paraneoplastic cushing’s syndrome?
small cell lung carcinoma
| rarer cause of Cushing's
119
what are symptoms of Cushing's syndrome?
- hypertension,
- moon face,
- abdominal obesity,
- buffalo hump,
- weak
muscles,
- osteoporosis,
- insomnia,
- excess sweating, - mood swings,
- headaches,
- chronic fatigue.
- Women may have increased hair growth (hirsuitism) and irregular menstruation.
120
excess production of what hormone is seen in Conn's syndrome? what does this lead to?
aldosterone
leads to low renin levels
121
what are signs and symptoms of conn's syndrome?
- high BP,
- headache,
- muscular weakness,
- muscle spasms,
- excessive
urination,
- cardiac arrythmias.
