What Is an Insulinoma?

Insulinoma refers to the excessive secretion of insulin caused by pancreatic -cell tumors or -cell proliferation, which causes hypoglycemia; its insulin secretion is not inhibited by hypoglycemia. Hypoglycemia is a group of syndromes characterized by low blood glucose levels caused by a variety of causes. Generally, venous plasma glucose concentration (determined by glucose oxidase method) is <2.8mmol / L (50mg / dl) as hypoglycemia. Diagnostic criteria; clinical symptoms and signs are mainly sympathetic nervous system excitement and central nervous system depression.

Basic Information

English name

insulinoma

Visiting department

Oncology

Common causes

Islet -cell tumor or -cell hyperplasia causes excessive insulin secretion

Common symptoms

Pale complexion, cold limbs, cold sweats, palpitations, soft hand trembling, drowsiness, lethargy, coma, loss of consciousness, closed teeth, twitching of limbs, etc.

Clinical manifestations of insulinoma

Insulinoma often has the typical Whipple triad, that is, symptoms of hypoglycemia, coma, and neuropsychiatric symptoms, which are easy to attack on fasting or after work.

Sympathetic nerve excitement

It is a compensatory reaction caused by hypoglycemia, such as pale, cold limbs, cold sweats, palpitations, and soft legs.

2. Disorder of consciousness

It is caused by lack of glucose in brain cells caused by hypoglycemia, such as mental drowsiness, drowsiness, coma, etc .; it can also be manifested as unclear head, slow response, and mental retardation.

3. Mental disorders

As a result of the recurrence of hypoglycemia, the cerebral cortex is further suppressed, and the symptoms are diverse. The severe ones have obvious mental symptoms and are sometimes misdiagnosed as mental illness.

4. Temporal lobe epilepsy

Similar to a major epileptic seizure, it is the most severe neuropsychiatric symptom, loss of consciousness, closed teeth, twitching of limbs, and incontinence during the attack.

Insulinoma test

Biochemical examination

Hematuria routine, ESR, liver and kidney function, HbA1c levels, tumor markers.

2. Glycemic hormone test

Blood adrenocorticotropic hormone, blood F and 24-hour UFC, fasting value of IGF-1 and growth hormone, thyroid function, 24-hour urinary catecholamines; if necessary, relevant axial excitability tests can be performed. Closely monitor blood glucose, check blood glucose, insulin, proinsulin, and C-peptide when blood glucose drops, and check urine ketone body at the same time. Perform hunger tests if necessary.

3. Screening for anti-insulin antibodies in the circulation.

4. Localization of insulinoma

Transabdominal ultrasound, endoscopic ultrasound, pancreatic perfusion CT, octreotide imaging, and selective arteriography if necessary.

5. Screening for multiple endocrine adenoma disease.

Insulinoma diagnosis

Close monitoring of blood glucose confirmed the presence of Whipple's triad in patients. Insulinoma often has the typical Whipple triad, that is:

1. Symptoms of hypoglycemia, coma, and neuropsychiatric symptoms, which occur every abdomen or after work;

2. Blood glucose is lower than 2.8mmol / L at the onset;

3. Symptoms can disappear immediately after oral or intravenous glucose injection. In addition, detailed medical history, physical examination and analysis of the results of existing laboratory tests are needed to find clues to other causes, such as drugs that cause hypoglycemia, serious diseases, hypoglycemic hormone deficiency and non-islet cell tumors.

Insulinoma treatment

The main treatment is to treat the primary disease. Tumor resection or cytoreductive surgery is the first choice. For those who cannot undergo surgery or metastatic tumor recurrence, it can be supplemented with somatostatin therapy, systemic or local chemotherapy, and isotope-labeled somatostatin therapy. The perioperative period, those who cannot be operated or those whose symptoms are not relieved should be treated symptomatically, such as correcting hypoglycemia.

Insulinoma prevention

Hypoglycemia is prone to occur for those who do not know the cause of hypoglycemia, especially for patients with diabetes who use hypoglycemic drugs (including exogenous insulin and oral hypoglycemic drugs). At this time, even if the dose of hypoglycemic drug is reduced or the hypoglycemic drug is stopped, the possibility of concomitant insulinoma should be suspected. You must go to the hospital as soon as possible and check and diagnose under the guidance of a specialist. Once diagnosed, early surgical treatment should be performed to prevent irreversible changes in the central nervous system after prolonged illness, such as brain atrophy, severe functional impairment or obesity. Those who are not suitable for surgery should also actively use medication.