Endocrine Disease

Question 1

What are the three classes of pituitary tumours?

Answer 1

Non-cancerous (rare), secretory (cancerous - hormonal effects), non-secretory (cancerous - mass effects)

Question 2

State the most common secretory adenoma and explain the symptoms observed.

Answer 2

Lactotroph (Lactotrope adenoma)

• increased lactation => increased production of prolactin (stimulates milk production)
• prevention of ovulation => decrease in LH, no LH available for the LH surge required for ovulation

Question 3

Name the types of secretory adenomas found in the pituitary.

Answer 3

Lactotroph, gonadotroph, somatotroph, corticotroph, thyrotroph

Question 4

Define primary, secondary and tertiary cause of disease

Answer 4

Primary - issue with target organ/gland
Secondary - pituitary dysfunction
Tertiary - hypothalamic dysfuntion

Question 5

Explain Hashimoto’s disease and how it is related to hypothyroidsm.

Answer 5

Hashimoto’s disease is an autoimmune disease in which the body produces autoantibodies against self-thyroid cells. The body amounts an immune response to kill the cells resulting in a decreased thyroid function. Due to the destruction of thyroid cells, T3 and T4 production is decreased an TSH is upregulated but cannot be utilised.

Question 6

What is the primary cause of hypothyroidism?

Answer 6

Hashimotos disease
(iodine deficiency, congential, surgery/radioiodine therapy)

Question 7

Explain hypothyroidism associated goitre.

Answer 7

Goitre is caused due to iodine deficiency within the body. Due to the lack of iodine, hormones T3 and T4 cannot be synthesised within the thyroid gland. The absence of T3 and T4 stimulates the release of TSH, but it cannot be utilised to increase T3 and T4 levels as no iodine is present. The thyroid gland increases in size to compensate.

Question 8

What are some symptoms observed in hypothyroidism?

Answer 8

Low metabolic rate, weight gain, sensitivity to cold temperatures, thinning hair, dry skin, goitre, constipation, slow speech + mental responses.

Question 9

Explain the causes and clinical symptoms related to hyperthyroidism.

Answer 9

Hyperthyroidism is an overactive thyroid gland caused by Grave’s disease. Thyroid stimulating immunoglobulin (TSI) stimulates the overproduction of T4. Increase in T4 results in decreased production of TSH.

Clinical symptoms; increased metabolic rate, weight loss, heat sensitivity, bulging eyes (grave’s disease), increase in thyroid size.

Question 10

What is Toxic Multinodular Goitre?

Answer 10

Form of goitre
Thyroid hyperplasia
characterised by hyperfunctioning nodules and ability to function independently of TSH stimulation.
NOT ASSOCIATED WITH GRAVE’S DISEASE SYMPTOMS

Question 11

Compare and contrast hyper- and hypo- thyroidism.

Answer 11

Hyper = overactivity
caused by TSI via stimulation of T4 production, decrease in TSH (grave’s disease).
symptoms = high metabolic rate, heat sensitivity, weight loss, bulging eyes (due to grave’s).

hypo = underactivity
caused by Hashimoto’s or iodine deficiency, decrease in T3 and T4 production, increased production of TSH which cannot be utilised.
symptoms = slow metabolic rate, weight gain, cold sensitivity, thinning hair, slow speech + mental responses, etc.

Question 12

Define hypercortisolism/hyperadrenalism.

Answer 12

Excess cortisol production, excess cortisol or steroid hormone use

Question 13

Explain the relationship between Cushing’s disease and hyperadrenalism.

Answer 13

Cushing’s disease results in increased production of ACTH from pituitary. Increase in ACTH results in an increase/overproduction of cortisol in the adrenal gland.

Question 14

Explain hypoadrenalism.

Answer 14

Caused/known as Addison’s disease
Autoimmune disease results in destruction of hormones made in adrenal gland (cortisol and aldosterone)
Symptoms = lethargy, weight loss, loss of appetite, hyperpigmentation, dehydration, low blood pressure, low Na conc. in blood but high K levels.

Question 15

Match the common names/causes to medical names

a) hyperadrenalism i) Grave’s Disease
b) hypoadrenalism ii) Hashimoto’s Disease
c) hyperthyroidism iii) Addison’s disease
d) hypothyroidism iv) Cushing’s disease

Answer 15

a + iv
b + iii
c + i
d + ii

Question 16

Describe treatments for cushing’s disease and their potential side effects.

Answer 16

Cushing disease generally due to tumour (hyper production of cortisol => inc. CRH, ACTH, cortisol)
Treated using enzyme inhibitors which act generally on the cholesterol to cortisol pathway.
Side effects = low testosterone/estrogen levels due to potential blocking of cholesterol to sex steroid hormones. Liver failure + drug-drug interactions

Question 17

Explain the treatments available for Addison’s disease.

Answer 17

Hypoadrenalism - low ACTH levels
supplement with corticosteroids to replenish levels
(2/3 dose in AM, 1/3 dose in PM)

Question 18

How should dosage of Addison’s disease change during times of stress?

Answer 18

When body is under stress, adrenal glands increase production cortisol, use up ACTH, therefore dosage should be increased to cater for increased corticosteriod utilisation.

Question 19

Which drug class is used to treat Conn’s disease (high aldosterone levels) and how does it work?

Answer 19

Aldosterone inhibitors
Inhibits aldosterone action
Results in the loss of Na and H2O and retains K levels

Question 20

What are some of the potential side effects of the use of aldosterone inhibitors in the treatment of diseases other than Conn’s disease?

Answer 20

Dehydration (low H2O), hyponatremia (low Na), hyperkalemia (high K), breast enlargement

Question 21

Describe a common treatment for hypothyroidism

Answer 21

Thyroxin supplements.
Given at 50-100 microgram daily
Half life of 1 week, 5-6 weeks to reach steady state

Question 22

How should dosage of thyroxin supplements be altered for patients with ischemic heart disease?

Answer 22

Dosage should be decreased from 50-100 microgram per day to 25-50 micrograms and slowly increased until thyroid function becomes normal.

Question 23

What are two potential treatment methods that could be used for hyperthyroidism?

Answer 23

Surgical removal of lesion, medical treatment to block thyroid hormone synthesis.

Question 24

What is acromegaly and how is it treated?

Answer 24

Acromegaly = over growth of muscles and bones due to over production of Growth Hormone (GH).
Since over production of GH is associated with pituitary lesions, surgery can be used.
GH inhibiting hormones (injections) can also be used to inhibit the action of GH on the body

Question 25

What is the treatment associated with GH deficiency and what are it’s side-effects?

Answer 25

supplementation with synthetic growth hormone (via injection)
Side effects = joint, muscle and growth pain, high sugar levels and swelling (edema).

Question 26

Match the pituitary adenoma with their effector hormones.

a) lactotroph i) LH + prolactin
b) gonadotroph ii) GH
c) somatotroph iii) LH and FSH
d) cortocotroph iv) ACTH
e) thyrotroph v) TSH

Answer 26

a + i
b + iii
c + ii
d + iv
e + v