Endocrinology 4

Question 1

Types of Ectopic hormone secretion

1. SCLC of lung produces?
2. Squamous lung produces?
3. HCC produces?
4. choriocarcinoma/hydatidform mole/testes
5. Breast cancer

Answer 1

1. SCLC of lung = SIADH ( low Na)
   SCLC of lung = ACTH ( low K)
2. Squamous cancer of lung = PTH ( hypercalcemia)
3. HCC = EPA ( Polycythemia)
   HCC = Insulin growth factor ( low BGL)
4. Choriocarcinoma/hydatidform mole/testes = TSH
5. Breast cancer = GNRH ( gynecomastia/galatorrhoea)

Question 2

Schmidt syndrome - what is it?

Answer 2

T1DM a/w adrenal insufficiency/autoimmune Thyroid!

Question 3

White adipocytes - what is it?

Brown adipocytes - what is it?

Answer 3

White =Normal adipose tissue

Brown
Uncoupling protein (UCP1) + Iron mitochondria
-convert fat into heat

-found in paravetebral/supraclavicular region

Question 4

MEN4 - what gene mutation and features?

Answer 4

CDNK1B

-Anterior pituitary + Parathyroid tumours

Question 5

Pagets’ mutation - SQSTM1 causes what?

Answer 5

Prevents p62 to bind to ubiquitin

SO RANKL have freedom! and activates osteoclast

Question 6

Diabetic gastroparesis

• what causes autonomic neuropathy?
• what causes enteric neuropathy?
• what causes iatrogenic neuropathy?

Answer 6

Autonomic neuropathy - vagal nerve problem

Enteric neuropathy - Loss Interstitial cells of Cajal!= delay gastric emptying

iatrogenic neuropathy - GLP1-agonist drug = blocks vagal nerve

Question 7

How does high glucose causes diabetic gastroparesis?

Answer 7

Pyloric muscle contractions but antral hypomotility due to acute hyperglycemic state

Question 8

When do you start thiazides for Diabetes insipidus?

Answer 8

Once urine volume > 4L/day

Question 9

Work up for Pheochromocytoma?

there are 4 lines of work-up

Answer 9

1st line = Plasma metanephrine

2nd line = 24 hours urine fractionated catecholamines/metanephrines

3rd line = MRI - hyperintense tumor

4th line = MIBG scan ( metadobenzylguanidine) - resembles norepinephrine taken up by pheochromocytoma

*Use 4th line esp. if CT/MRI can’t detect or multiple tumors

Question 10

Highest specificity test for pheo?

Lowest accuracy test for pheo?

Answer 10

Urinary EPInephrine

Plasma catecholamines

Question 11

what side effect strongly a/w Dapagliflozin?

Answer 11

UTI!!

Question 12

Majority of thyroid carcinoma - driver mutation comes from what pathway?

Answer 12

MAPK pathway

Commonest - BRAF V600E mutations! RAS 2nd

Question 13

Transgender people
aim hormone estradiol and testosterone at what level?

When is GnRH analogues used?

Answer 13

Estradiol - 300 - 600
Testosterone < 0.2

GnRH analogues only in adolescents as puberty blocker

Question 14

Bariatric surgery

-What mineral deficiency likely with Roux-en-Y bypass and Biliopancreatic diversion?

Answer 14

RYGB and BPD = Zinc deficiency

Question 15

Types of bariatric surgery

Restrictive?
Malabsorption?
Mixed

Answer 15

Restrictive = Gastric sleeve/banding

Malabsoprtion = BPD - biliopancreaticodiversion

Mixed - Roux-En-Y bypass

Question 16

According to Tirads score for thyroid nodules
when suspicious of malignancy?

when to FNA biopsy?

Answer 16

Micro-calcifications
Taller than wide
Hypo-echoic
Solid
Irregular/lobulated margin

High suspicious : > 1 cm
Moderate suspicion : > 1.5 cm
Low suspicious : > 2 - 2.5cm

Question 17

PCOS has 4 phenotypes
Which type;
No hyperandrogenism?
No oligomenorrhea?
No PCOS on ultrasound?
Has all features of PCOS - HOPE mneumonic

Answer 17

No hyperandrogenism = D phenotype
No oligomenorrhea = C phenotype
No PCOS on US = B phenotype
All features = A phenotype

Question 18

When adrenal tumor is carcinoma - based on contrast washout?

Answer 18

< 50% washout in 10 minutes

Tumor hungry - ABSORB contrast

Question 19

FRAX parameters?

FRAS mnemonic

Answer 19

Fracture/Fracture in parents
Femoral Neck BMD
RA
Age/Weight/Height etc
Steroids usage/Smoking/Drinking > 3 SD per day

Question 20

High index suspicion of Pheochromocytoma - what test?

IF CT/MRI doesn’t show pheo but still suspect- do what test?

Answer 20

Plasma metanephrines - more sensitive and specific

MIBG (metaiodobenzylguanidine) scintigraphy - form of compound like epinephrine which will be taken up by pheochromocytoma

Question 21

AME pathogenesis ( apparent mineralocorticoid excess)?

Answer 21

cortisol > aldosterone bcoz deficient of 11-B-HSD2,
So high cortisol, high aldosterone!

11B-HSD2 converts cortisol into cortisone ( inactive form)

Question 22

Liddle syndrome pathogenesis?

Answer 22

ENAC mutation - so keep reabsorbing Na ( resistant to degradation by aldosterone)

Question 23

Liquorice pathogenesis?

Answer 23

Liquorice inhibits 11B-HSD2

Question 24

Glucocorticoid-remediable aldosteronism (GRA) pathogenesis?

Answer 24

11 Beta hydroxlase mutation - so Cortisol and Aldosterone controlled by ACTH

Tx - steroids to suppress ACTH - so reduce aldosterone and cortisol production