Pituitary Disorders & Addison’s Crisis — MRCP Part 1 Guide
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Pituitary Disorders & Addison’s Crisis — MRCP Part 1 Guide

TL;DR


Pituitary and adrenal disorders are core topics in MRCP Part 1, especially prolactinomas, growth hormone excess, Addison’s disease, and adrenal crisis. Questions typically test biochemical interpretation and emergency management. This guide summarises the highest-yield facts, exam traps, and clinical reasoning needed to answer endocrine questions accurately.


Why this matters

Endocrinology provides a consistent proportion of questions in MRCP Part 1, and pituitary–adrenal disorders are among the most predictable areas. Candidates are expected to recognise laboratory patterns, imaging findings, and appropriate management.

Pituitary tumours such as prolactinomas and growth hormone–secreting adenomas test physiology and investigation strategies, while Addison’s disease and adrenal crisis test emergency recognition and treatment.

For a structured overview of the exam curriculum see:

Practise endocrine interpretation questions here:

You can reinforce these topics with structured teaching:


Scope of This Topic

This article focuses on the most frequently tested endocrine conditions:

  • Hyperprolactinaemia and prolactinomas

  • Growth hormone excess (acromegaly)

  • Addison’s disease

  • Adrenal crisis

  • Pituitary hormone interpretation

These topics commonly appear as single best answer questions requiring recognition of diagnostic patterns.


Five Most Tested Subtopics

1. Prolactinomas and Hyperprolactinaemia

Prolactinomas are the most common functioning pituitary adenomas.

Typical clinical features include:

  • Amenorrhoea

  • Galactorrhoea

  • Infertility

  • Reduced libido

  • Erectile dysfunction

  • Headache

  • Visual disturbance

Key biochemical findings:

  • Raised prolactin

  • Suppressed gonadotropins

  • Low testosterone or oestradiol

High-yield exam facts:

  • Prolactinomas cause very high prolactin levels

  • MRI pituitary confirms diagnosis

  • Dopamine agonists are first-line therapy

Cabergoline is usually preferred because of better tolerability and effectiveness.

Common drug causes of hyperprolactinaemia:

  • Antipsychotics

  • Metoclopramide

  • SSRIs

  • Verapamil

Drug-induced hyperprolactinaemia usually causes mild or moderate elevation rather than extreme levels.


2. Prolactinoma vs Stalk Compression

This differentiation is a classic exam question.

Moderate prolactin elevation may occur due to interruption of dopaminergic inhibition when the pituitary stalk is compressed by a tumour.

Feature

Prolactinoma

Stalk Compression

Prolactin

Very high

Moderately elevated

Cause

Pituitary adenoma

Non-functioning mass

Treatment

Dopamine agonist

Treat underlying lesion

Key exam rule:

Very high prolactin strongly suggests prolactinoma, while modest elevation suggests stalk compression or drugs.


3. Growth Hormone Excess (Acromegaly)

Acromegaly is caused by GH-secreting pituitary adenomas.

Typical clinical features:

  • Enlarged hands and feet

  • Prognathism

  • Coarse facial features

  • Hyperhidrosis

  • Headaches

Associated diseases:

  • Hypertension

  • Diabetes mellitus

  • Cardiomyopathy

  • Obstructive sleep apnoea

  • Colon polyps

Key investigations:

  • Raised IGF-1

  • Failure of GH suppression during oral glucose tolerance test

High-yield exam fact:

IGF-1 is the best screening test for acromegaly.

Authoritative reference:


4. Addison’s Disease (Primary Adrenal Insufficiency)

Primary adrenal insufficiency is commonly tested because of its characteristic biochemical pattern.

Common causes:

  • Autoimmune adrenalitis

  • Tuberculosis

  • Metastases

  • Adrenal haemorrhage

Typical symptoms:

  • Fatigue

  • Weight loss

  • Hypotension

  • Hyperpigmentation

  • Salt craving

Characteristic laboratory findings:

  • Hyponatraemia

  • Hyperkalaemia

  • Low cortisol

  • High ACTH

Hyperpigmentation occurs due to increased ACTH stimulating melanocytes.

Authoritative reference:


5. Adrenal Crisis

Adrenal crisis is a life-threatening emergency and frequently appears in MRCP questions.

Common triggers:

  • Infection

  • Surgery

  • Trauma

  • Sudden steroid withdrawal

Typical presentation:

  • Hypotension

  • Vomiting

  • Abdominal pain

  • Confusion

  • Shock

Emergency Management (High-Yield Steps)

  1. Give IV hydrocortisone 100 mg immediately

  2. Take blood for cortisol and ACTH (if possible)

  3. Give IV 0.9% saline

  4. Correct hypoglycaemia with dextrose

  5. Treat underlying cause

  6. Continue IV hydrocortisone

Key exam principle:

Treatment must not be delayed while waiting for blood tests.

Authoritative reference:


High-Yield Points for Rapid Revision

  1. Prolactinoma is the most common pituitary adenoma

  2. Dopamine agonists are first-line therapy

  3. MRI pituitary confirms diagnosis

  4. IGF-1 is best screening test for acromegaly

  5. OGTT confirms GH excess

  6. Hyperpigmentation suggests primary adrenal failure

  7. Hyponatraemia with hyperkalaemia suggests Addison’s disease

  8. Tuberculosis remains an important global cause

  9. Hydrocortisone is first-line treatment in adrenal crisis

  10. Visual field defects suggest macroadenoma


Practical Example (Typical MRCP Question)

A 39-year-old woman presents with amenorrhoea and galactorrhoea. Prolactin is 6800 mIU/L. MRI shows a 5 mm pituitary adenoma.

What is the most appropriate treatment?

A. SurgeryB. RadiotherapyC. CabergolineD. ObservationE. Oestrogen therapy

Answer: Cabergoline

Explanation

Microprolactinomas are treated first-line with dopamine agonists such as cabergoline. Surgery is reserved for resistant disease.

This is a classic endocrine question format in MRCP Part 1.


Practical Study Tip Checklist

Use this checklist when revising endocrine topics:

  • Memorise biochemical patterns

  • Learn diagnostic thresholds

  • Recognise emergencies

  • Practise interpretation questions

  • Learn first-line treatments

  • Revise imaging indications

  • Learn drug causes

  • Use timed question practice

Simulate exam conditions here:


Common Pitfalls

  • Treating prolactinoma with surgery first-line

  • Using GH instead of IGF-1 for screening

  • Missing hyperkalaemia in Addison’s disease

  • Delaying hydrocortisone in adrenal crisis

  • Assuming all raised prolactin indicates prolactinoma

Doctor revising endocrinology for MRCP Part 1 examination

FAQs

What pituitary topics are most common in MRCP Part 1?

Prolactinomas and acromegaly are the most frequently tested pituitary disorders. Questions usually focus on biochemical interpretation and first-line treatment.

What is the best screening test for acromegaly?

Serum IGF-1 is the recommended screening test. Diagnosis is confirmed with an oral glucose tolerance test showing failure of growth hormone suppression.

How is adrenal crisis treated in MRCP questions?

Immediate IV hydrocortisone and IV saline are essential. Blood tests should be taken first if possible, but treatment must not be delayed.

How do you distinguish prolactinoma from drug-induced hyperprolactinaemia?

Drug-induced hyperprolactinaemia usually causes mild or moderate prolactin elevation. Very high prolactin levels strongly suggest prolactinoma.


Suggested Illustrative Table

Condition

Best Initial Test

Confirmatory Test

First-Line Treatment

Prolactinoma

Prolactin level

MRI pituitary

Cabergoline

Acromegaly

IGF-1

OGTT

Surgery

Addison’s disease

Morning cortisol

Synacthen test

Hydrocortisone

Adrenal crisis

Clinical diagnosis

None required

IV hydrocortisone

Ready to start?

Strengthen your endocrine revision with structured resources from Crack Medicine:


Sources

NICE Acromegaly Guidelinehttps://www.nice.org.uk/guidance/ng48

British Society for Endocrinology

British Society for Endocrinology – Adrenal Crisishttps://www.endocrinology.org/clinical-practice/clinical-guidance/adrenal-crisis/

 
 
 
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