### Date : 2024-06-19 18:12 ### Topic : Pituitary Adenomas (Cushing's Disease) #medicine #internalmedicine ---- ### Pituitary Adenomas (Cushing's Disease) Overview **Pituitary adenomas** are benign tumors of the pituitary gland that can cause a variety of hormonal imbalances. When a pituitary adenoma secretes excessive adrenocorticotropic hormone (ACTH), it leads to Cushing's disease, a specific form of Cushing's syndrome. This excess ACTH stimulates the adrenal glands to produce high levels of cortisol, resulting in the characteristic symptoms of Cushing's disease. ### Pathophysiology In Cushing's disease, the pituitary adenoma secretes excess ACTH, which stimulates the adrenal cortex to produce excessive amounts of cortisol. This overproduction of cortisol disrupts various body functions, leading to the clinical manifestations of the disease. ### Clinical Features **Physical Symptoms:** - **Weight Gain:** Especially around the abdomen, face (moon face), and upper back (buffalo hump). - **Skin Changes:** Thin, fragile skin that bruises easily, and purple striae (stretch marks) on the abdomen, thighs, and breasts. - **Muscle Weakness:** Particularly in the proximal muscles (e.g., hips, shoulders). - **Osteoporosis:** Increased risk of fractures due to bone loss. [[Understanding the relationship between cortisol and osteoporosis]] - **Hypertension:** High blood pressure. - **Hyperglycemia:** High blood sugar levels, which can lead to diabetes. **Psychological Symptoms:** - **Mood Changes:** Depression, anxiety, and irritability. - **Cognitive Impairment:** Memory and concentration difficulties. **Other Symptoms:** - **Menstrual Irregularities:** Irregular or absent periods in women. - **Hirsutism:** Excessive hair growth in women. - **Decreased Libido and Erectile Dysfunction:** In men. ### Diagnosis Diagnosis of Cushing's disease involves a combination of clinical evaluation, laboratory tests, and imaging studies: 1. **Clinical History and Physical Examination:** - Detailed assessment of symptoms and physical signs suggestive of Cushing's disease. 2. **Laboratory Tests:** - **24-Hour Urinary Free Cortisol:** Measures cortisol levels in urine collected over 24 hours. - **Late-Night Salivary Cortisol:** Measures cortisol levels in saliva late at night. - **Low-Dose Dexamethasone Suppression Test:** Evaluates how cortisol levels respond to synthetic glucocorticoids. In Cushing's disease, cortisol levels do not suppress adequately. - **Plasma ACTH Levels:** Elevated ACTH levels suggest a pituitary source. 3. **Imaging Studies:** - **MRI of the Pituitary Gland:** Preferred imaging modality to identify pituitary adenomas. ### Example Case Study **Patient Profile:** - **Name:** Jee Hoon Ju - **Age:** 45 - **Occupation:** Accountant **Medical History:** - **Symptoms:** Jee Hoon Ju reports significant weight gain, especially around his abdomen and face, with purple stretch marks on his abdomen. He also experiences high blood pressure, elevated blood sugar levels, and mood changes, including irritability and depression. **Physical Examination:** - **Facial Appearance:** Rounded face (moon face). - **Upper Back:** Fat deposition (buffalo hump). - **Skin:** Thin skin with purple striae on the abdomen. **Laboratory Tests:** - **24-Hour Urinary Free Cortisol:** Elevated cortisol levels. - **Late-Night Salivary Cortisol:** Elevated cortisol levels. - **Low-Dose Dexamethasone Suppression Test:** No significant suppression of cortisol levels. - **Plasma ACTH Levels:** Elevated. **Imaging:** - **MRI of the Pituitary Gland:** Reveals a small pituitary adenoma. **Diagnosis:** Based on the clinical features, laboratory test results, and imaging findings, Jee Hoon Ju is diagnosed with Cushing's disease due to a pituitary adenoma. ### Management 1. **Surgical Treatment:** - **Transsphenoidal Surgery:** The primary treatment for removing the pituitary adenoma. This minimally invasive surgery is performed through the nasal passages and is highly effective. 2. **Radiation Therapy:** - Considered if surgery is not completely successful or if the tumor recurs. Types include conventional radiotherapy or stereotactic radiosurgery (e.g., Gamma Knife). 3. **Medications:** - **Steroidogenesis Inhibitors:** Medications like ketoconazole, metyrapone, or mitotane to reduce cortisol production if surgery and radiation are not viable or as adjunctive therapy. - **Pituitary-Directed Drugs:** Medications such as cabergoline or pasireotide to reduce ACTH production from the adenoma. 4. **Monitoring and Follow-Up:** - Regular monitoring of cortisol levels and clinical symptoms. - Lifelong follow-up to detect recurrence or manage any long-term complications of the disease or its treatment. 5. **Management of Complications:** - **Hypertension:** Antihypertensive medications. - **Hyperglycemia:** Blood sugar management with diet, medications, or insulin. - **Osteoporosis:** Calcium and vitamin D supplements, bisphosphonates. ### Prognosis - The prognosis for Cushing's disease is generally good if the tumor is successfully removed and managed. - Regular follow-up is essential to monitor for recurrence and manage any long-term effects of hypercortisolism. ### Conclusion Cushing's disease, caused by ACTH-secreting pituitary adenomas, leads to excess cortisol production with widespread effects on the body. Early diagnosis and treatment, primarily through transsphenoidal surgery, are crucial for managing symptoms and improving patient outcomes. Continuous monitoring and follow-up care are essential to ensure long-term health and detect any potential recurrences.