Endocrine Investigations

Question 1

First line investigation for thyroid cancer
And other investigations

Answer 1

1st) Ultra sound
Thyroid function
TSH receptor antibodies (TRAP)

No role for isotope scan/CT/MRI

Question 2

screening test for excess cortisol (cushings)

Answer 2

best:
-overnight dexamtheasone suppression test
- 24 hr urinary free cortisol

Other:
-late night salivary cortisol

Question 3

diagnostic test for cushings

Answer 3

low dexamethasone suppression test
(measure cortisol and aCTH at baseline and 48 hrs, normal response to supress. failure to supress diagnosis cushings syndrome. diagnoses cushings but not the cause)

Question 4

diagnosis of primary aldosteronism

Answer 4

-confirm aldosterone excess
check aldosterone: renin ratio via saline supression test

• confirm subtype by doing abdo CT and AVS (adrenal venous sampling) to find out if its unilateral or bilateral

Question 5

diagnostic test for Addisons

Answer 5

short synACTHen test

inject ACTH, in Addisons cortisol won’t increase as adrenal glands don’t work

Question 6

conns syndrome Ix

Answer 6

blood biochem, urinary potassium loss >30mmol/day, adrenal CT scan (for adenoma)

Question 7

diagnostic criteria for diabetes

Answer 7

fasting>7.0, random >11.1- if asymptomatic need 2 readings

hba1c> 48mmol diagnostic in symptomatic patient

Question 8

test for acromegaly

Answer 8

1st line: Serum IGF-1 levels

confirm diagnosis: oral glucose tolerance test (OGTT) with serial GH measurement

Question 9

phaecromocytoma IXs

Answer 9

do 24 hr urinary metanephrines, not catecholamines

Question 10

What does simmonds test, test

Answer 10

Achilles tendon rupture

Question 11

How to work out hyperosomlality

Answer 11

(2xNa) + glucose + urea

Question 12

What is classed as hyperosomolality and what is hyperosmolality seen in

Answer 12

> 320mmol/L

Seen in HHS

Question 13

initial investigation for someone with a fever who is taking carbimazole

Answer 13

blood test
this is to check for neutropenia (low platelets) which can be caused by carbimazole

Question 14

high dose dexamethasone results for
pituitary adenoma
adrenal adenoma
ecoptic ACTH eg small cell lung cancer

Answer 14

PA: low acth, low cortisol (as acth dependant)
adrenal adenoma: low ACT, high cortisol (as ACTH independant)
ectopic ACTH: high ACTH, high cortisol (as ACTH isnt being produced from pituitary so does not respond to test)

Question 15

clinical examinations for hypoparathyroidism

Answer 15

chvosteks sign: tapping parotid= facial twitching
trousseaus sign: carpal spasm (fingers adduct, wrist flexes) when bp cuff on

Question 16

scintigraphy: faint diffuse uptake/ no uptake

Answer 16

subacute thyroiditis

Question 17

scintigraphy: increased homogenous uptake

Answer 17

graves

Question 18

suspected diabetes inspidus testing

Answer 18

1st investigate PTH levels and serum calcium as hypercalcaemia due to hyperparathyroidism needs to be excluded

2nd- diagnostic: water deprivation test

Question 19

what is diagnostic of osteomalacia

Answer 19

low vit D, hypocalcaemia, low serum phosphate, raised ALP

Question 20

Ix for non functional thyroid nodule

Answer 20

ultrasonography of neck

Fine needla aspiration (FNA) may be inidicated