Multiple endocrine neoplasia syndromes - NYSORA

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Multiple endocrine neoplasia syndromes

Learning objectives

  • Define multiple endocrine neoplasia syndromes
  • Describe the differences between MEN type 1 and MEN type 2
  • Anesthetic management of patients with multiple endocrine neoplasia syndromes

Definition and mechanisms 

  • Multiple endocrine neoplasia (MEN) syndromes are characterized by hyperplasia of or a tumor in specific endocrine system glands and tissues
  • Caused by a genetic mutation, autosomal dominant inheritance


MEN type 1

  • Genetic condition in which multiple tumors affect different aspects of the endocrine system
  • Most common affected areas: Parathyroid glands, gastroenteropancreatic tract, and anterior pituitary gland
  • Less common types of tumors: Neuroendocrine tumors of the thymus and bronchi, adrenocortical tumors, lipomas, visceral leiomyomas, truncal and facial collagenomas, facial angiofibromas, breast cancer, meningioma, ependymomas
  • Most tumors are benign
  • Tumors are due to the inactivation of the MEN 1 oncosuppressor gene located on chromosome 11q13

MEN type 2

  • Genetic polyglandular cancer syndrome
  • All patients develop medullary thyroid carcinoma and have an increased risk of developing other tumors affecting other endocrine glands
  • Patients with MEN type 2 also develop one or both of the following conditions
  • Tumors result from oncogenic point mutations of the c-Ret proto-oncogene located on chromosome 10cen-10q11.2

Signs and symptoms

  • Symptoms vary depending on which glands are affected by the hyperplasia or tumor
  • Hyperplasia or tumors cause the affected glands to produce and release more hormones than normal
  • Symptoms vary from person to person 

MEN type 1 

Tumor/conditionIncidenceAssociated hormoneSymptoms
Hyperparathyroidism90%Parathyroid hormoneRelated to hypercalcemia
Mild: Joint pain, muscle weakness, fatigue, depression, trouble concentrating, loss of appetite
Severe: Nausea and vomiting, confusion and forgetfulness, increased thirst and frequent urination, constipation, bone pain
Gastrinomas40%GastrinAbdominal pain, diarrhea, gastroesophageal reflux (acid reflux), peptic ulcers
Insulinomas10%InsulineRelated to hypoglycemia
Confusion, shakiness, sweating, hunger, anxiety, heart palpitations, temporary vision changes
Prolactinomas25%ProlactinWomen: Changes in menstruation unrelated to menopause (i.e., irregular menstruation or amenorrhea), infertility, milky discharge from the nipples when not pregnant or breastfeeding (galactorrhea), decreased libido
Men: Decreased libido, erectile dysfunction, infertility
Large tumor: Nausea and vomiting, vision changes (i.e., double vision or decreased peripheral vision)

MEN type 2

Tumor/conditionIncidenceAssociated hormoneSymptoms
Medullary thyroid carcinoma100%Lump and pain in front of the neck, voice changes (e.g., hoarseness), coughing, trouble swallowing, dyspnea
Pheochromocytomas50%Epinephrine and norepinephrineHypertension, headache, excessive sweating, tachycardia, arrhythmia, feeling shaky
Hyperparathyroidism20%Parathyroid hormoneRelated to hypercalcemia
Mild: Joint pain, muscle weakness, fatigue, depression, trouble concentrating, loss of appetite
Severe: Nausea and vomiting, confusion and forgetfulness, increased thirst and frequent urination, constipation, bone pain


MEN type 1MEN type 2
DiagnosisAt least two of the three endocrine tumors associated with the condition
One of the associated tumors and a family history
Medullary thyroid carcinoma and pheochromocytoma and/or parathyroid enlargement (hyperplasia) or tumor (adenoma)
TestsBlood tests to detect elevated levels of certain hormones
- Hyperparathyroidism: Parathyroid hormone + hypercalcemia
- Gastrinomas: Gastrin
- Insulinomas: Insulin
- Prolactinomas: Prolactine
CT and MRI scans
Genetic testing of MEN 1 gene
Blood tests to detect elevated levels of certain hormones
- Medullary thyroid carcinoma: Calcitonin
- Pheochromocytoma: Catecholamines
- Hyperparathyroidism: Parathyroid hormone + hypercalcemia
CT and MRI scans
Genetic testing of RET gene


Dependent on what endocrine glands and organs are affected, treatment may include

  • Medications to treat symptoms and counteract the side effects of excess hormones
  • Surgery to remove tumors or entire affected glands (e.g., thyroidectomy, parathyroidectomy)
  • Replacement hormones if an endocrine gland is surgically removed
  • Cancer treatment (e.g., chemotherapy and radiation) in case of metastasis


MEN, Multiple endocrine neoplasia syndromes, hypercalcemia, hypoglycemia, Pheochromocytoma, hormone hypersecretion, malignant neoplasm, thyroid

Anesthetic challenges per tumor

  • Parathyroid tumors: Hypercalcemia 
    • Maintain hydration and urinary output 
    • Main risk: Potential for cardiac dysrhythmias
    • Unpredictable responses to muscle relaxants 
    • Careful positioning due to the possible presence of osteoporosis and the potential for pathologic fractures
  • Gastrinomas
  • Insulinomas: Hypoglycemia
    • Maintain normal blood glucose concentrations to prevent cerebral damage
      • Place an intra-arterial catheter to measure glucose levels regularly 
      • Administer IV glucose 
    • Anesthetic technique should focus on agents that decrease the cerebral metabolic rate for oxygen (avoid ketamine)
    • Maintain normocarbia during controlled ventilation
    • Patients might be obese → pay attention to the airway and address respiratory and cardiac issues
  • Prolactinoma
    • No specific anesthetic considerations
  • Medullary thyroid carcinoma
    • Enlarged thyroid causing airway compromise 
    • Intraoperative damage to the recurrent laryngeal nerve → may cause hoarseness, stridor, and complete airway obstruction upon extubation of the trachea or in the PACU
    • Airway may also become compromised by hematoma formation compressing the trachea
  • Pheochromocytoma: Hypertension
    • Prevent hypertension and tachycardia → smooth anesthesia induction and endotracheal intubation
    • Avoid catecholamine release induced by anesthetic or surgical maneuvers 
    • Correct hypovolemia and electrolyte imbalances

See also hyperparathyroidism considerations

See also pheochromocytoma considerations

Keep in mind

  • The anesthetic course may range from routine with no special requirements to severe and life-threatening depending on the tumor
  • Some syndromes demand specific management techniques, but a carefully and thoughtfully administered anesthetic is the key to a successful outcome in patients with MEN

Suggested reading

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