Acromegaly

Disease Description (Causes and Symptoms)

• Definition/Pathophysiology: Excessive secretion of growth hormone (GH) from the anterior pituitary causes elevated blood IGF-1 levels and progressive enlargement of bone and soft tissue. If it occurs before closure of the growth plates, it causes gigantism; if it occurs afterward, it causes acromegaly.
• Main cause: Most commonly, a GH-secreting pituitary adenoma (a benign hormone-producing tumor). Rarely, other causes include exogenous GH administration and GHRH secretion by non-endocrine tumors.
• Main symptoms:
  • Enlargement of the extremities (hands, feet, jaw, nose, etc.), facial changes (protruding lower jaw, thickened nose), and skin changes (excessive sweating, oily skin)
  • Voice changes (hoarseness), joint pain and reduced joint function (degenerative arthropathy)
  • Headache, visual field impairment (when the optic nerve is compressed), and fatigue
  • Endocrine/metabolic: insulin resistance → diabetes, hypertension, and possible cardiomegaly and heart failure
  • Increased risk of complications: sleep apnea and increased risk of colorectal polyps and cancer (in some studies)
• Diagnosis (summary): Elevated blood IGF-1 is the key screening test. In an oral glucose tolerance test (OGTT) to assess GH suppression, GH is not adequately suppressed. Pituitary MRI is used to assess tumor size and invasion. Visual field testing (to identify visual field defects) and related endocrine tests (to determine whether other hormone deficiencies are present) are performed.

Treatment Methods

• Goals: Normalize GH/IGF-1, relieve symptoms and complications by removing or reducing the tumor, preserve vision, and prevent complications.
• 1. Surgery
  • Transsphenoidal surgery is the first-line treatment, particularly when there is optic nerve compression or a giant tumor. The complete resection rate depends on the surgeon’s experience.
  • Complications: diabetes insipidus, cerebrospinal fluid leakage, pituitary dysfunction, infection, etc.
• 2. Medication Treatment
  • Somatostatin analogs (injectable): octreotide, lanreotide — suppress GH secretion and reduce tumor size; administered once monthly or at modified intervals. Side effects may include gastrointestinal symptoms, gallstones, and possible worsening of blood glucose.
  • GH receptor antagonist: pegvisomant — blocks the effects of GH in peripheral tissues and is effective for normalizing IGF-1. Liver function monitoring is required. Changes in tumor size must be monitored.
  • Dopamine agonists: cabergoline, bromocriptine — oral medications used for mild disease or tumors that also secrete prolactin. Their effect as monotherapy is limited, but they are useful in some patients.
• 3. Radiation Therapy
  • Selectively used for residual tumors or when surgery and medication are ineffective. Precise focused radiation techniques such as Gamma Knife and CyberKnife are used.
  • Long-term hormone normalization takes time (several years), and the risk of pituitary dysfunction (hormone deficiency) increases after radiation.
• 4. Lifestyle Management and Monitoring
  • Blood glucose and blood pressure management, cardiac evaluation (echocardiography), and sleep apnea testing when necessary.
  • Regular blood tests (IGF-1 and, when necessary, GH), pituitary MRI (with frequency adjusted), and visual field testing.
• Precautions/Self-management
  • Monitor medication-specific side effects (gastrointestinal symptoms, gallstones, changes in liver enzyme levels, etc.)
  • Actively manage coexisting conditions such as diabetes and hypertension
  • Report immediately if visual symptoms or symptoms of diabetes insipidus (such as decreased sweating or a sudden increase in urine volume) occur after surgery
• Complications
  • Cardiovascular complications (cardiomegaly, heart failure, hypertension), metabolic complications (diabetes), joint disease (degenerative changes), sleep apnea, colorectal lesions (increased risk of polyps and cancer), and treatment-related pituitary dysfunction

Outpatient Visit Checklist (Including Preparation Items and Sample Questions)

• Items to bring/check in advance
  • A list of all current medications and supplements, including doses and administration times
  • Previous test results (IGF-1, GH, OGTT results, recent MRI, visual field test results, HbA1c, echocardiography, etc.)
  • When symptoms began, changes in symptoms (photos can be useful), and breathing or sleep symptoms (whether sleep apnea is suspected)
  • History of previous brain surgery or radiation therapy and other medical history (heart disease, diabetes)
  • Pregnancy plans (for women) or whether breastfeeding
• Examples of basic questions to ask the doctor during an outpatient visit
  • "Is my current IGF-1 level within the normal range? What is the target level?"
  • "Do you recommend surgery, or do you recommend starting with medication?"
  • "What are the main side effects of the medication, and how will they be monitored?"

Examples of General Questions to Ask the Doctor

• Regarding treatment/prognosis
  • "What is the likelihood that treatment will completely cure the disease? What is the risk of recurrence?"
  • "What tests should I have regularly after treatment, and how often?"
• Regarding medications/procedures
  • "What are the advantages, disadvantages, and side effects of the medication you recommend?"
  • "How likely are long-term side effects of radiation therapy, particularly hormone deficiency?"

Examples of Disease-Specific Questions

• "My tumor is compressing the optic nerve/surrounding structures. Is this a situation requiring immediate surgery? What is the likelihood that surgery will restore my vision?"
• "I am planning a pregnancy. How should GH/IGF-1 be managed before, during, and after pregnancy? Do I need to stop the medication?"