Acromegaly USMLE Notes

Acromegaly USMLE Notes & mnemonics contains all the high-yield points you need to know.

Definition:

• Acromegaly: A rare hormonal disorder caused by excess growth hormone (GH) production, usually due to a pituitary adenoma. (Ref)

Pathophysiology:

• GH Hypersecretion: Leads to liver producing more Insulin-Like Growth Factor 1 (IGF-1), promoting growth of bones and soft tissues.
• Pituitary Adenoma: Most common cause.

Epidemiology:

• Typically diagnosed in middle-aged adults.
• Rare, with an incidence of about 3 per million per year.

Clinical Features:

• Enlarged Hands and Feet
• Coarse Facial Features: Prognathism, enlarged nose, lips, and tongue.
• Macroglossia
• Sweating and Skin Tags
• Joint Pain and Arthritis
• Carpal Tunnel Syndrome
• Hypertension, Cardiomegaly
• Impaired Glucose Tolerance/Diabetes

Diagnosis:

• Elevated IGF-1 Levels: Reflects integrated GH levels.
• Oral Glucose Tolerance Test (OGTT): Lack of GH suppression after glucose administration confirms diagnosis.
• MRI of the Pituitary Gland: To detect adenoma.

Management:

• Transsphenoidal Surgery: First-line for pituitary adenomas.
• Somatostatin Analogs (e.g., Octreotide, Lanreotide): Reduce GH production.
• GH Receptor Antagonists (e.g., Pegvisomant): Block GH effects.
• Dopamine Agonists (e.g., Cabergoline): Reduce GH in some patients.
• Radiation Therapy: For uncontrolled cases after surgery and medications.

Complications:

• Cardiovascular Disease
• Sleep Apnea
• Colon Polyps and Increased Risk of Colorectal Cancer
• Hypopituitarism (post-treatment)

Prognosis:

• Normal life expectancy if adequately treated; increased mortality if untreated, primarily due to cardiovascular complications.

Mnemonic: “ACRO-MEGALY”

• Adults (commonly middle-aged)
• Coarse facial features
• Ring size increases (enlarged hands)
• Organomegaly (heart, liver, etc.)
• Macroglossia
• Enlarged feet
• Growth hormone excess
• Arthralgia
• Lanreotide & Octreotide (treatment options)
• You see pituitary adenoma on MRI

Chart: Diagnostic Approach to Acromegaly

Note: For the USMLE, focus on the classic presentation of acromegaly, including its insidious onset and distinctive physical changes. Recognize the importance of IGF-1 and OGTT in diagnosis and understand the first-line treatments and their purposes. Be aware of the complications and the need for lifelong follow-up due to the risk of tumor recurrence and development of comorbid conditions.

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