2.5 Adrenal & Pituitary Disorders

ABIM Internal Medicine Exam

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1 Chapter 0: The ABIM Exam, Blueprint & Study Strategy

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2 Chapter 1: Cardiovascular Disease (14% of Exam)

1.1 Ischemic Heart Disease & Acute Coronary Syndromes 1.2 Antithrombotic Therapy, Secondary Prevention & Mechanical Complications of MI 1.3 Atrial Fibrillation, Atrial Flutter & Stroke Prevention 1.4 Supraventricular Tachycardias, Ventricular Arrhythmias & Bradycardias 1.5 Heart Failure: Classification, Staging & Guideline-Directed Medical Therapy 1.6 Device Therapy, HFpEF & the Cardiomyopathies 1.7 Valvular Heart Disease & Endocarditis Prophylaxis 1.8 Pericardial Disease & Acute Aortic Syndromes 1.9 Hypertension: Classification, Diagnosis & Secondary Causes 1.10 Hypertensive Crises & Dyslipidemia 1.11 Adult Congenital Heart Disease & Coarctation of the Aorta 1.12 Syncope: Reflex, Orthostatic & Cardiac Causes 1.13 Cardiac Physical Examination, Murmurs & Antithrombotic Selection

3 Chapter 2: Endocrinology, Diabetes & Metabolism (9% of Exam)

2.1 Diabetes Mellitus: Diagnosis, Glycemic Targets & Pharmacotherapy 2.2 Insulin Therapy, Hyperglycemic Emergencies & Chronic Complications 2.3 Thyroid Function Testing & Hypothyroidism 2.4 Thyrotoxicosis, Thyroid Storm & Thyroid Nodules 2.5 Adrenal & Pituitary Disorders 2.6 Hypercalcemia, Hypocalcemia & Disorders of Mineral Metabolism 2.7 Osteoporosis & Paget Disease of Bone 2.8 Ovarian, Testicular & Reproductive Endocrine Disorders 2.9 Hypoglycemia, Endocrine Tumors, Polyglandular Syndromes & Severe Hypertriglyceridemia

4 Chapter 3: Gastroenterology & Hepatology (9% of Exam)

3.1 Esophageal Disease 3.2 Stomach & Duodenal Disease and Gastrointestinal Hemorrhage 3.3 Inflammatory Bowel Disease 3.4 Celiac Disease & Irritable Bowel Syndrome 3.5 Diverticular Disease & Colorectal Cancer Screening 3.6 Viral Hepatitis, Steatotic & Alcohol-Associated Liver Disease 3.7 Cirrhosis & the Complications of Portal Hypertension 3.8 Acute Pancreatitis 3.9 Chronic Pancreatitis & Biliary Tract Disease 3.10 Inherited, Autoimmune & Drug-Induced Liver Disease 3.11 Small Intestinal Disease, Ischemia & Gastrointestinal Complications of HIV

5 Chapter 4: Infectious Disease (9% of Exam)

4.1 Lower Respiratory Tract Infections & Sepsis Syndromes 4.2 Viral Respiratory Pathogens & Tuberculosis 4.3 Central Nervous System Infections 4.4 Skin, Soft Tissue, Bone & Joint Infections 4.5 Infective Endocarditis & Cardiovascular Infection 4.6 Clostridioides difficile & Catheter-Related Bloodstream Infection 4.7 HIV Diagnosis, Antiretroviral Therapy & Prevention 4.8 Opportunistic Infections & Sexually Transmitted Infections 4.9 Fever of Unknown Origin, Neutropenic Fever & Toxic Shock 4.10 Travel-Related Illness, Vector-Borne Disease & Outbreaks 4.11 Infection Prevention, Nosocomial Infection & Postexposure Prophylaxis 4.12 Rheumatic Fever, Poststreptococcal Disease, Enteric & Hepatic Infections

6 Chapter 5: Pulmonary Disease (9% of Exam)

5.1 COPD: Diagnosis, GOLD Classification & Initial Pharmacotherapy 5.2 Interventions That Reduce COPD Mortality & Exacerbation Management 5.3 Asthma: Diagnosis, Stepwise Therapy & Status Asthmaticus 5.4 Interstitial Lung Disease & Idiopathic Pulmonary Fibrosis 5.5 Sarcoidosis, Hypersensitivity Pneumonitis & Occupational Lung Disease 5.6 Pulmonary Embolism: Diagnosis, Risk Stratification & Anticoagulation 5.7 Pulmonary Hypertension & Sleep-Disordered Breathing 5.8 Acute Respiratory Distress Syndrome & Mechanical Ventilation 5.9 Pleural Disease, Empyema & Pneumothorax 5.10 Bronchiectasis, Cystic Fibrosis & Restrictive Lung Disease 5.11 Evaluation of Cough, Dyspnea, Hemoptysis & the Solitary Pulmonary Nodule

7 Chapter 6: Rheumatology & Orthopedics (9% of Exam)

6.1 Rheumatoid Arthritis: Diagnosis & Systemic Manifestations 6.2 Antirheumatic Pharmacotherapy & the Spondyloarthropathies 6.3 Gout: Pathophysiology & Acute Management 6.4 Urate-Lowering Therapy & Calcium Pyrophosphate Deposition Disease 6.5 Osteoarthritis 6.6 Systemic Lupus Erythematosus 6.7 Systemic Sclerosis, Sjogren Syndrome & Inflammatory Myopathies 6.8 The Vasculitides 6.9 Regional Musculoskeletal Syndromes, Back Pain & Sports Injuries 6.10 Other Primary Rheumatic Disorders & Mixed Connective Tissue Disease 6.11 Osteonecrosis & Metabolic Bone Disease

8 Chapter 7: Hematology (6% of Exam)

7.1 Approach to Anemia & the Microcytic Anemias 7.2 Macrocytic, Normocytic & Hemolytic Anemias 7.3 Hemoglobinopathies, Thalassemias & Paroxysmal Nocturnal Hemoglobinuria 7.4 Platelet Disorders, Thrombocytopenia & the Bleeding Patient 7.5 Coagulation Factor Disorders, Thrombophilia & Anticoagulant Reversal 7.6 Acute Leukemias, Chronic Leukemias & Myeloproliferative Neoplasms 7.7 Lymphomas & Plasma Cell Disorders 7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria 7.9 Transfusion Medicine & Late Complications of Transplantation

9 Chapter 8: Medical Oncology (6% of Exam)

8.1 Breast, Lung, Colorectal & Prostate Cancer 8.2 Oncologic Emergencies 8.3 Genitourinary & Gynecologic Malignancies 8.4 Head and Neck, Bone & Soft Tissue Cancer and Cancer of Unknown Primary 8.5 Complications of Cancer & Its Treatment 8.6 Cancer Prevention, Survivorship & Psychosocial Care

10 Chapter 9: Nephrology & Urology (6% of Exam)

9.1 Acute Kidney Injury: Staging, Etiology & Urine Microscopy 9.2 Glomerular Disorders & Nephrotic Syndrome 9.3 Nephritic Syndromes, RPGN & Indications for Renal Replacement Therapy 9.4 Chronic Kidney Disease: Staging & Progression Retardation 9.5 Complications of Chronic Kidney Disease: Anemia, CKD-MBD & Acidosis 9.6 Hyponatremia, Hypernatremia & Water Balance 9.7 Potassium Disorders & Systematic Acid-Base Analysis 9.8 Renal Tubular Acidosis & Nephrolithiasis 9.9 Prostate Disorders, Urinary Incontinence & Other Urologic Conditions 9.10 Cystic Kidney Disease, Obstructive Uropathy, Tubulointerstitial Disease & Hematuria

11 Chapter 10: Neurology (4% of Exam)

10.1 Acute Ischemic Stroke: Syndromes & Reperfusion 10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke 10.3 Headache & Facial Pain 10.4 Seizures, Epilepsy & Movement Disorders 10.5 Multiple Sclerosis & Neuromuscular Junction Disorders 10.6 Motor Neuron Disease & Acute Peripheral Neuropathy 10.7 Cranial Neuropathies & Neuro-Ophthalmology 10.8 Peripheral Neuropathies, CNS Tumors & Other Neurologic Disorders

12 Chapter 11: Psychiatry & Behavioral Health (4% of Exam)

11.1 Major Depressive Disorder & Medical Mimics 11.2 Antidepressant Pharmacotherapy & Treatment-Resistant Depression 11.3 Bipolar Disorder, Mood Stabilizers & Lithium Toxicity 11.4 Anxiety, Stress-Related & Obsessive-Compulsive Disorders 11.5 Alcohol Use Disorder & Withdrawal 11.6 Pharmacotherapy for Alcohol & Opioid Use Disorder 11.7 Toxidromes, Psychiatric Emergencies & Suicide Risk Assessment 11.8 Psychotic, Somatic Symptom, Factitious & Personality Disorders 11.9 Eating Disorders, Sleep Disorders & Sexual Health

13 Chapter 12: Dermatology (3% of Exam)

12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses 12.2 Acne, Rosacea & Cutaneous Infections 12.3 Herpes Zoster & Autoimmune Blistering Diseases 12.4 Nodules, Tumors & Cutaneous Oncology 12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions 12.6 Pigment Disorders, Alopecia, Nail Disease & Photosensitivity 12.7 Vascular Dermatoses, Environmental Injury & Cutaneous Signs of Systemic Disease

14 Chapter 13: Obstetrics & Gynecology / Women's Health (3% of Exam)

13.1 Contraception, Preconception Care & Teratogenicity 13.2 Hypertensive Disorders of Pregnancy & Gestational Diabetes 13.3 Thyroid Disease & Venous Thromboembolism in Pregnancy 13.4 Menopause & Menopausal Hormone Therapy 13.5 Abnormal Uterine Bleeding, Endometrial Disease & Gynecologic Cancer Screening 13.6 Breast Disorders & Diseases of the Vulva and Vagina 13.7 Menstrual Disorders, Fibroids, Endometriosis & Early Pregnancy Complications

15 Chapter 14: Geriatric Syndromes (3% of Exam)

14.1 Comprehensive Geriatric Assessment & Frailty 14.2 Falls, Gait Assessment & Polypharmacy 14.3 Urinary Incontinence & Pressure Injuries in Older Adults 14.4 Mild Cognitive Impairment, Dementia & Its Subtypes 14.5 Delirium & the Pharmacotherapy of Cognitive Disorders 14.6 Palliative Care, Hospice & Advance Care Planning 14.7 Chronic Wounds, Nutrition, Swallowing, Constipation & Hip Fracture 14.8 Sensory Impairment, Dizziness, Elder Mistreatment & Care Settings

16 Chapter 15: Allergy & Immunology (2% of Exam)

15.1 Anaphylaxis: Recognition & Emergency Management 15.2 Urticaria & Angioedema 15.3 Drug Allergy, Desensitization & Adult Immunodeficiency 15.4 Food Allergy, Insect Venom Hypersensitivity, Serum Sickness & Contrast Reactions 15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders

17 Chapter 16: Preventive Medicine, Immunization & Clinical Epidemiology

16.1 The USPSTF Framework & Evidence-Based Cancer Screening 16.2 Cardiovascular & Metabolic Screening and Primary Prevention 16.3 Adult Immunization & Vaccines in Special Populations 16.4 Clinical Epidemiology, Biostatistics & Study Design

18 Chapter 17: Miscellaneous - Ethics, Patient Safety & Quality Improvement (2% of Exam)

17.1 Principles of Bioethics & Decisional Capacity 17.2 Informed Consent, Treatment Refusal & Special Scenarios 17.3 Surrogate Decision-Making, Advance Directives & Confidentiality 17.4 Patient Safety Science, Medical Error & Diagnostic Reasoning 17.5 Quality Improvement Methods, Health Disparities & Health Equity

19 Chapter 18: Perioperative Medicine & Medical Consultation

18.1 Preoperative Cardiovascular Risk Assessment 18.2 Preoperative Pulmonary Risk & Perioperative Medication Management 18.3 Perioperative Anticoagulation, Bridging & Postoperative Complications

20 Chapter 19: Ophthalmology (1% of Exam)

19.1 The Acute Red Eye & Ophthalmic Emergencies 19.2 Painless Vision Loss & Chronic Ophthalmic Disease 19.3 Uveitis, Scleritis & Orbital Disease

21 Chapter 20: Otolaryngology & Dental Medicine (1% of Exam)

20.1 Dizziness, Vertigo & Epistaxis 20.2 Ear Disorders, Hearing Loss & Upper Respiratory Infections 20.3 Oral Cavity, Salivary Gland, Laryngeal & Taste and Smell Disorders

2.5 Adrenal & Pituitary Disorders

Key Takeaways Explain This Topic AI

Adrenal hormonal excess, adrenal insufficiency and adrenal masses form one blueprint subsection; hypothalamic, anterior pituitary and posterior pituitary disorders are three more.

Primary adrenal insufficiency produces hyperkalemia and hyperpigmentation with a markedly elevated corticotropin level; secondary insufficiency does not.

Treatment of suspected adrenal crisis with stress-dose glucocorticoid must precede confirmatory testing.

Alpha-blockade must be established before beta-blockade in pheochromocytoma, because unopposed alpha stimulation precipitates hypertensive crisis.

Endocrine causes of secondary hypertension are a distinct blueprint subsection, and primary aldosteronism is confirmed biochemically before any imaged nodule is assumed to be the source.

Last updated: August 2026

Adrenal and pituitary diseases present with complex hormonal excesses and deficiencies. The ABIM examination emphasizes discriminating primary from secondary/ectopic endocrine etiologies, mastering dynamic stimulation and suppression testing, and executing strict preoperative pharmacologic sequences.

1. Adrenal Insufficiency & Acute Adrenal Crisis

Primary vs. Secondary / Tertiary Adrenal Insufficiency +-------------------------------------------------------------------------------------------------------------+

| FEATURE | PRIMARY ADRENAL INSUFFICIENCY (Addison) | SECONDARY / TERTIARY INSUFFICIENCY |

+---------------------+-----------------------------------------------+---------------------------------------+

• | Anatomical Site | Adrenal Cortex (> 90% destruction) | Pituitary (ACTH) / Hypothalamus (CRH) |
• | Common Etiologies | Autoimmune adrenalitis (21-hydroxylase Abs), | Abrupt steroid withdrawal (most common|
• | | TB, fungal, adrenal hemorrhage (Waterhouse- | Pituitary adenoma, surgery, apoplexy, |
• | | Friderichsen, HIT, APS), Checkpoint inhibitors| Sheehan syndrome, infiltrative disease|
• | Hormones Deficient | Glucocorticoid (Cortisol) AND | Glucocorticoid (Cortisol) ONLY; |
• | | Mineralocorticoid (Aldosterone) + DHEA | Aldosterone is INTACT (RAAS regulated)|
• | Plasma ACTH | Markedly ELEVATED (> 100-200 pg/mL) | LOW or Inappropriately Normal |
• | Hyperpigmentation | PRESENT (buccal mucosa, palmar creases, scars)| ABSENT (Skin is pale / alabaster) |
• | Serum Electrolytes | Hyponatremia, HYPERKALEMIA, non-anion gap | Hyponatremia (SIADH-like free water |
• | | metabolic acidosis (aldosterone deficiency) | retention); POTASSIUM IS NORMAL |
• | Daily Replacement | Hydrocortisone/Prednisone PLUS | Hydrocortisone or Prednisone ONLY |
• | | Fludrocortisone (0.05-0.2 mg/day) | (Fludrocortisone is NOT needed) |

+-------------------------------------------------------------------------------------------------------------+

Diagnostic Workup of Adrenal Insufficiency

Morning Serum Cortisol & Plasma ACTH (8:00 AM):

Serum Cortisol < 3 mcg/dL: Confirms adrenal insufficiency.

Serum Cortisol > 18 mcg/dL: Excludes adrenal insufficiency.

Serum Cortisol 3–15 mcg/dL: Indeterminate; mandates dynamic stimulation testing.

High-Dose Cosyntropin (Synthetic ACTH 1–24) Stimulation Test:

Administer 250 mcg Cosyntropin IV or IM ; measure serum cortisol at 0, 30, and 60 minutes.

Normal Response: Peak serum cortisol >= 18 mcg/dL (500 nmol/L).

Primary AI: Subnormal cortisol rise (<18 mcg/dL) with elevated baseline plasma ACTH.

Secondary/Tertiary AI: Subnormal cortisol response due to chronic adrenal cortical atrophy (or normal acutely in very recent pituitary injury; evaluate with insulin tolerance test or metyrapone test if acute pituitary injury suspected).

Acute Adrenal Crisis: Emergent Resuscitation

Clinical Presentation: Refractory distributive and hypovolemic shock unresponsive to vasopressors, high fever, abdominal pain mimicking acute peritonitis, severe vomiting, lethargy, hyponatremia, hyperkalemia, and hypoglycemia.

Emergency Protocol:

Immediate IV Hydrocortisone: Administer 100 mg IV bolus stat , followed by 50–100 mg IV every 6–8 hours (or continuous infusion of 200 mg/24 hours). Never delay treatment to perform a cosyntropin stimulation test. (If dynamic testing is desired, Dexamethasone 4 mg IV can be given as it does not cross-react with serum cortisol assays).

Aggressive Crystalloid Resuscitation: Rapid infusion of 0.9% Normal Saline + 5% Dextrose (D5NS) to treat volume depletion, hypotension, and hypoglycemia.

Mineralocorticoid Note: High-dose hydrocortisone (>=100 mg/day) saturates mineralocorticoid receptors; fludrocortisone is unnecessary in the acute crisis phase.

Sick-Day Rules for Chronic AI: During minor febrile illnesses (fever >38°C / 100.4°F), patients must double or triple their oral hydrocortisone dose for 3 days ("3x3 rule"). For severe vomiting/diarrhea or major surgery, administer intramuscular hydrocortisone (100 mg IM) and present to the emergency department.

2. Cushing Syndrome (Hypercortisolism)

Cushing syndrome encompasses the signs and symptoms of prolonged exposure to inappropriately high glucocorticoid levels.

Clinical Features

Central obesity, moon facies, facial plethora, dorsocervical and supraclavicular fat pads ("buffalo hump"), wide violaceous cutaneous striae (>1 cm) on the abdomen and flanks, proximal muscle weakness (difficulty standing from a chair without arms), easy bruising from minimal trauma, severe osteoporosis/vertebral fractures, hypertension, glucose intolerance, and neuropsychiatric changes.

Screening & Diagnostic Algorithm (Rule of 2 Tests)

First-line screening requires at least two concordant abnormal screening tests from the following three validated modalities:

24-Hour Urinary Free Cortisol (UFC): > 3x upper limit of normal.

Late-Night Salivary Cortisol (>=2 measurements at 11:00 PM): Elevated (demonstrates loss of normal circadian cortisol nadir).

1 mg Overnight Dexamethasone Suppression Test (DST): Administer 1 mg dexamethasone at 11:00 PM; measure serum cortisol at 8:00 AM. Normal suppression is cortisol < 1.8 mcg/dL (50 nmol/L); failure to suppress (>1.8 mcg/dL) confirms hypercortisolism.

Loading diagram... Cushing Syndrome Diagnostic & Localization Algorithm

3. Primary Aldosteronism (Conn Syndrome)

Primary aldosteronism (PA) is the most common cause of secondary hypertension, accounting for 5–10% of all hypertensive patients and up to 20% of patients with resistant hypertension.

Clinical Suspicion & Screening

Indications for Screening: Resistant hypertension (uncontrolled on 3 antihypertensives including a diuretic, or requiring >=4 drugs), hypertension with spontaneous or diuretic-induced hypokalemia, hypertension with adrenal incidentaloma, or hypertension with family history of early-onset stroke (<40 yo).

Screening Test: Morning, ambulatory Plasma Aldosterone Concentration (PAC in ng/dL) and Plasma Renin Activity (PRA in ng/mL/hr) .

Positive Screen: PAC / PRA Ratio (ARR) > 20–30 with an absolute PAC >= 15 ng/dL and suppressed renin ( PRA < 1.0 ng/mL/hr \text{PRA} < 1.0\text{ ng/mL/hr} PRA < 1.0 ng/mL/hr ).

Testing Conditions: Correct hypokalemia before testing; discontinue mineralocorticoid antagonists (Spironolactone, Eplerenone) for 4–6 weeks prior to ARR measurement.

Confirmatory Testing: Oral sodium loading test (24-hour urine aldosterone >12 mcg/24h with urine sodium >200 mEq/24h) or IV Saline Infusion Test (2 L 0.9% NS over 4 hours; post-infusion PAC >10 ng/dL confirms autonomous production).

Subtype Differentiation & Targeted Therapy

Thin-Section Adrenal CT: Identifies large adrenocortical carcinoma and structural lesions.

Adrenal Venous Sampling (AVS): Mandatory in surgical candidates before adrenalectomy. Adrenal CT frequently misidentifies non-functional incidentalomas or misses microadenomas. AVS measures cortisol-corrected aldosterone ratios from both adrenal veins.

Unilateral Aldosterone-Producing Adenoma (APA) (Lateralization >4:1): Treat with Laparoscopic Unilateral Adrenalectomy (cures hypokalemia in 100%, cures/improves hypertension in >85%).

Bilateral Idiopathic Hyperplasia (IHA) (No lateralization): Treat medically with Mineralocorticoid Receptor Antagonists: Spironolactone (first-line, 25–100 mg/day; causes gynecomastia/impotence via anti-androgen effects) or Eplerenone (selective MRA, fewer side effects).

4. Pheochromocytoma & Paraganglioma

Pheochromocytomas are catecholamine-producing neuroendocrine chromaffin cell tumors of the adrenal medulla (paragangliomas arise from extra-adrenal sympathetic/parasympathetic ganglia).

Clinical Presentation & Genetics

Classic Paroxysmal Triad: Severe episodic headache, profuse diaphoresis, and tachycardia/palpitations in the setting of paroxysmal or sustained hypertension. Other symptoms: tremor, pallor, orthostatic hypotension (from contracted intravascular volume), and hyperglycemia.

Hereditary Associations (~35–40%): MEN 2A/2B ( RET ), Von Hippel-Lindau ( VHL ), Neurofibromatosis Type 1 ( NF1 ), and Succinate Dehydrogenase subunit mutations ( SDHB , SDHD ).

Diagnostic & Preoperative Protocol

Biochemical Diagnosis:

High-risk / Inpatient: Plasma Free Fractionated Metanephrines (highest sensitivity: 97–99%).

Standard / Outpatient: 24-Hour Urinary Fractionated Metanephrines and Catecholamines (high specificity).

Values > 3x upper reference limit confirm diagnosis.

Anatomical & Functional Imaging: Contrast-enhanced CT or MRI of abdomen/pelvis (classic hyperintense "lightbulb" sign on T2 MRI); functional imaging with 123-I MIBG or 68-Ga DOTATATE PET/CT for extra-adrenal or metastatic tumors.

CRITICAL Preoperative Medical Blockade Sequence:

Step 1 (Alpha-Blockade FIRST): Initiate Phenoxybenzamine (non-selective, non-competitive alpha-1/alpha-2 antagonist, 10 mg twice daily, titrating to orthostasis/nasal congestion) or selective alpha-1 blockers (Doxazosin, Terazosin) for 10–14 days preoperatively .

Step 2 (Volume Expansion): High-sodium diet and generous oral fluids starting on day 2–3 of alpha-blockade to restore contracted intravascular volume.

Step 3 (Beta-Blockade SECOND): Add Propranolol, Atenolol, or Metoprolol 2–3 days prior to surgery to treat reflex tachycardia ONLY AFTER establishing adequate alpha-blockade.

LETHAL EXAM TRAP: Never initiate beta-blockade prior to adequate alpha-blockade! Unopposed alpha-1 receptor activation causes catastrophic peripheral vasoconstriction, leading to severe hypertensive crisis, acute pulmonary edema, and intracerebral hemorrhage.

• 5. Pituitary Disorders & Pituitary Apoplexy
• Hyperprolactinemia

Etiology: Prolactinoma (microadenoma <10 mm, macroadenoma >=10 mm), medications (dopamine antagonists: haloperidol, risperidone, metoclopramide; SSRIs, verapamil), primary hypothyroidism (elevated TRH stimulates prolactin), and pituitary stalk compression ("stalk effect" with prolactin usually <100–150 ng/mL).

Clinical Manifestations: Women: galactorrhea, oligomenorrhea/amenorrhea, infertility; Men: decreased libido, erectile dysfunction, gynecomastia, mass-effect headaches/bitemporal hemianopsia.

Treatment: First-line therapy for both micro- and macroadenomas is Dopamine Agonist Therapy: Cabergoline (preferred over Bromocriptine due to higher efficacy, greater tumor shrinkage, and fewer GI side effects). Transsphenoidal surgery is reserved for drug-resistant tumors or acute visual deterioration.

Acromegaly

Pathophysiology: Autonomous Growth Hormone (GH) hypersecretion from a somatotroph pituitary macroadenoma (>75%), stimulating excessive hepatic production of Insulin-like Growth Factor-1 (IGF-1) .

Clinical Features: Acral enlargement (increase in hat/ring/shoe size), coarse facial features, prognathism, macroglossia, frontal bossing, carpal tunnel syndrome, obstructive sleep apnea, hypertension, cardiomyopathy, glucose intolerance, and increased risk of colorectal adenomas/adenocarcinoma (requires regular colonoscopy surveillance).

Diagnostic Protocol: Initial screening: Serum IGF-1 level (elevated; reflects integrated 24-hr GH levels). Confirmatory test: Oral Glucose Tolerance Test (OGTT with 75g glucose) ; normal individuals suppress GH to <1.0 mcg/L (or <0.4 mcg/L on sensitive assays); failure of GH suppression confirms acromegaly. Follow with pituitary MRI.

Treatment: Transsphenoidal surgery is first-line. Medical therapy for persistent disease: Somatostatin receptor ligands (Octreotide LAR, Lanreotide) , GH receptor antagonist ( Pegvisomant ), or Cabergoline.

Pituitary Apoplexy

Emergency Presentation: Acute infarction or hemorrhage into a preexisting pituitary adenoma. Characterized by sudden catastrophic severe headache ("thunderclap") , visual acuity loss, bitemporal hemianopsia, ophthalmoplegia (CN III, IV, VI compression in cavernous sinus), and acute panhypopituitarism with life-threatening secondary adrenal collapse.

Urgent Management: Immediate administration of Stress-Dose Glucocorticoids (Hydrocortisone 100 mg IV stat) to prevent fatal vascular collapse, emergent Pituitary MRI, and Urgent Neurosurgical Transsphenoidal Decompression within 24–48 hours for patients with visual field deficits or altered mental status.