Cushing Syndrome - Causes , Clinical Features , Diagnosis and Management | NEET PG | INI CET | FMGE

Unable to Access this Video ? Join our Channel Membership to Watch 1000+ of Premium Video on High Yield Topics of NEET PG , INI CET , FMGE and NeXT PG Exams at Just 159/- Month https://www.youtube.com/medicoapps/join Cushing's Syndrome Definition: Cushing's syndrome refers to the clinical condition resulting from chronic exposure to excessive glucocorticoids, either endogenous (overproduction of cortisol by the adrenal glands) or exogenous (prolonged use of corticosteroid medications). Causes Endogenous Causes: ACTH-Dependent (80-85%): Cushing’s Disease: Pituitary adenoma secreting ACTH. Ectopic ACTH Syndrome: ACTH production by non-pituitary tumors (e.g., small cell lung cancer, bronchial carcinoids). ACTH-Independent (15-20%): Adrenal Adenoma: Benign tumor of the adrenal gland. Adrenal Carcinoma: Malignant tumor of the adrenal gland. Adrenal Hyperplasia: Rare. Exogenous Causes (most common overall cause): Prolonged use of corticosteroids (e.g., prednisone) for conditions like rheumatoid arthritis or asthma. Clinical Features Systemic Symptoms: Weight gain. Fatigue and muscle weakness. Mood changes: Irritability, depression, or psychosis. Characteristic Signs: Fat Redistribution: Moon face. Buffalo hump (fat pad on the upper back). Central obesity with thin extremities. Skin Changes: Purple striae (stretch marks) on the abdomen, thighs, and breasts. Easy bruising. Thinning of the skin. Slow wound healing. Musculoskeletal: Proximal muscle weakness (difficulty climbing stairs or standing up). Osteoporosis (increased risk of fractures). Metabolic: Hypertension. Hyperglycemia or diabetes mellitus. Dyslipidemia. Other: Hirsutism (excess facial or body hair in females). Menstrual irregularities or amenorrhea in women. Impotence in men. Diagnosis Screening Tests: 24-Hour Urinary Free Cortisol: Elevated levels confirm hypercortisolism. Low-Dose Dexamethasone Suppression Test: Lack of cortisol suppression after dexamethasone suggests Cushing's syndrome. Late-Night Salivary Cortisol: Elevated levels due to the loss of diurnal variation in cortisol secretion. Differentiating ACTH-Dependent vs. Independent: ACTH Levels: Elevated: ACTH-dependent causes (Cushing’s disease, ectopic ACTH). Suppressed: ACTH-independent causes (adrenal tumor). Localization Tests: High-Dose Dexamethasone Suppression Test: Suppression indicates Cushing’s disease (pituitary source); no suppression suggests ectopic ACTH. Imaging: MRI of the pituitary: To detect adenomas. CT/MRI of the chest/abdomen: To detect ectopic ACTH-producing tumors or adrenal masses. Inferior Petrosal Sinus Sampling: Confirms pituitary ACTH secretion in cases of Cushing's disease. Management General Measures: Address complications: Control hypertension, hyperglycemia, and osteoporosis. Specific Treatment: Cushing’s Disease (Pituitary Adenoma): Surgery: Transsphenoidal resection of the adenoma (first-line treatment). Radiation Therapy: For residual or recurrent disease. Medical Therapy: If surgery is not an option. Drugs: Ketoconazole or metyrapone (inhibit cortisol synthesis). Pasireotide (reduces ACTH production). Ectopic ACTH Syndrome: Locate and treat the underlying tumor (e.g., surgical removal). Medical therapy to control cortisol if the tumor is inoperable. Adrenal Tumors: Adrenalectomy: Surgical removal of the tumor. Medical therapy (mitotane) for metastatic or inoperable adrenal carcinoma. Exogenous Cushing’s Syndrome: Gradual tapering of corticosteroids to allow adrenal recovery and prevent adrenal insufficiency. Postoperative Care: Temporary glucocorticoid replacement (hydrocortisone) may be needed after adrenal or pituitary surgery until adrenal function normalizes. Follow-Up: Regular monitoring of cortisol levels and associated complications. Bone density evaluation to manage osteoporosis. Prognosis Varies depending on the underlying cause. Early diagnosis and effective treatment improve outcomes significantly. Long-term monitoring is necessary to manage recurrence and complications.