Insulinoma is a tumor on the pancreas that is about twice as common in women as in men. Its incidence is considered rare; however, insulinoma is the most common tumor of the pancreas that releases hormones directly into the blood (“endocrine”). The malignancy of insulinomas is 10%, so one in nine such tumors is malignant.
What is insulinoma?
Insulinoma gets its name from the fact that it produces extra insulin, causing damage to the body with excess insulin. In nine out of ten cases, insulinoma develops as a single tumor; only rarely are so-called multiple microadenomas present. In about 50% of cases, the insulinoma produces not only insulin, but also other hormones of the digestive tract, such as vasoactive intestinal peptide (VIP), which is responsible for muscle relaxation of the stomach, intestines, trachea and bronchi, among other things. The symptoms of an insulinoma can also occur during the treatment of diabetes mellitus as a result of blood sugar-lowering medication. Similarly, a similar clinical picture is present in so-called hypoglycaemia factitia, in which patients deliberately induce hypoglycemia in order to attract medical attention or provoke a stay in hospital. Both of these diagnoses must be ruled out before determining an insulinoma.
Causes
In most cases, insulinomas arise from B cells of the islets of Langerhans on the pancreas that have undergone adenomatous transformation. This degeneration results in the production of vast amounts of insulin, which is released directly into the bloodstream by the pancreas. The ultimate cause of the development of these tumors has not yet been clarified in conventional medicine. However, insulinomas occur more frequently in the context of MEN (multiple endocrine neoplasia). This genetic disease results in tumors of the pancreas, parathyroid gland, and pituitary gland developing at a comparatively younger age, behaving extremely aggressively, and often recurring after already complete healing.
Symptoms, complaints, and signs
Insulinoma is characterized by what is known as Whipple’s triad. In Whipple’s triad, the blood glucose level is very low, with a value below 45 milligrams per deciliter. Furthermore, there are symptoms of severe hypoglycemia, which include confusion, dizziness, nausea, palpitations, palpitations and tingling, and numbness. The third sign is the rapid improvement of the symptoms with the intake of carbohydrates. The hypoglycemic episodes occur repeatedly with cravings, trembling and sweating. In the long term, weight gain also occurs, as the cravings lead to excess food intake. While the symptoms of hypoglycemia can be relieved in the short term by ingesting carbohydrates, in the long term, removal of the tumor must be considered. Without treatment and removal of the tumor, secondary damage to the central nervous system can occur because the constant undersupply of glucose causes many nerve cells to die, and these cells are then no longer replaced. Very often there is only one insulin-producing tumor in the pancreas. Sometimes several tumors are present. In rare cases, the tumor or tumors are also located outside the pancreas. The insulinoma itself does not cause any symptoms, only their increased production of insulin. In most cases, the tumors are benign and do not usually metastasize. However, in approximately ten percent of cases, malignant degeneration may occur.
Diagnosis and course
Insulinoma is suspected if there are recurrent symptoms of hypoglycemia. In so-called hypoglycemia, the glucose level in the blood is only at or below 50mg/dl. This is manifested by the typical symptoms also found in diabetes patients, such as sweating, trembling, ravenous appetite, dizziness, nausea, pallor, fatigue, impaired concentration, visual disturbances, rapid heartbeat (tachycardia) and violent, often irregular palpitations (palpitation). Classically, medicine speaks of the so-called “Whipple triad”, which combines a blood glucose level below 45mg/dl with the described symptoms of hypoglycemia, as well as improvement by infusion of glucose solutions.The longer the disease is not treated, the higher the risk of the patient becoming overweight, which is caused by the anabolic effect of insulin. This means that the patient constantly feels the need to consume food (especially carbohydrates) to keep his circulation stable due to the insulin excess. Diagnosis is made by fasting the patient for three days until symptomatic hypoglycemia occurs. Meanwhile, the patient’s blood is tested at regular intervals and the levels of blood glucose, insulin and C-peptide are recorded. If an insulinoma is present, a very rapid drop in blood glucose and an increase in the insulin-glucose ratio may be observed. The latter should drop in a healthy organism, because to the same extent that there is less glucose in the blood, the body should also stop producing insulin.
Complications
Insulinoma causes a variety of symptoms. These are usually highly dependent on the spread of the tumor, so it is usually not possible to make a general prediction about complications. However, many affected individuals suffer from severe ravenous hunger and also palpitations. Loss of consciousness may still occur. It is not uncommon for patients to also suffer from anxiety or sweating and headaches. In addition, there is often a feeling of dizziness and nausea. Those affected also complain of speech disorders and visual disturbances, and generally of a strong sense of disorientation. Thus, insulinoma has a significant negative impact on the patient’s quality of life. Sufferers also appear tired and fatigued and no longer take an active part in life. The insulinoma also significantly reduces and limits the patient’s ability to cope with stress. It is not uncommon for cramps to occur in the muscles, which can lead to restricted movement. The treatment itself does not lead to further complications. With the help of medication or radiation, the insulinoma can be removed relatively well. Surgical intervention can also be performed. If no treatment is given, insulinoma can also lead to the death of the patient.
When should you see a doctor?
Individuals who notice symptoms of hypoglycemia or other signs of serious illness should consult their primary care physician promptly. If symptoms such as rapid heartbeat, sweating, or headache are added to the symptoms, a doctor should also be consulted. Recurring attacks of ravenous appetite, muscle cramps, trembling and other non-specific symptoms should also be clarified if they are not due to a clear cause. At the latest, if visual or speech disorders are added or even consciousness disorders develop, a general practitioner must be consulted with the complaints. In case of serious complications, a visit to the hospital is indicated. People who lead an unhealthy lifestyle are particularly susceptible to developing an insulinoma. Past tumor diseases or complaints of the pancreas or parathyroid gland are also risk factors. Anyone who belongs to these risk groups must see a doctor immediately if they have any of the above-mentioned complaints. Diseases of the gastrointestinal tract should be presented to a gastroenterologist or the family doctor. Specialists for tumor diseases can also be consulted in case of mentioned complaints. After the initial diagnosis, further treatment in a specialized clinic is indicated.
Treatment and therapy
The first step in treating an insulinoma is to administer octreotide, an artificial replica of the peptide hormone somatostatin, which slows the release of gastrointestinal hormones, including insulin. About half of insulinomas respond to this treatment, and the insulin excess can be stopped. If the insulinoma is malignant, surgical removal, known in the medical field as “resection,” is inevitable. In about 10 to 15% of insulinoma cases, metastases occur in the liver. If metastases have already formed, or if surgery of the tumor is not possible, insulinoma is treated with interdisciplinary therapy together with chemotherapy and radiation therapy. For surgical removal or efficient radiation therapy, the insulinoma is first localized as precisely as possible using imaging techniques. If the tumor is already several centimeters in size, it can be localized using MRI, CT, or an ultrasound of the pancreas.Otherwise, the insulinoma can be detected via punctual determinations of the insulin level via the portal vein, which leads past the pancreas and into the liver. Once the location of the insulinoma is known, surgical intervention can be performed. Depending on how completely the tumor can be removed, further treatment involves chemotherapy and radiation therapy.
Outlook and prognosis
Insolinoma usually has a very good prognosis. In more than 90 percent of patients, surgery is sufficient to remove the tumor without leaving any residue. Complications occur in the first few weeks after surgery but subside in the long term. Occasionally, larger parts of the pancreas must be removed in addition to the tumor. This can cause diabetes in some patients. In addition, a recurrence may develop after a few years. In this case, a new operation is necessary. Patients who have not been completely cured must have regular follow-up examinations. On the one hand, this can cause physical problems, as repeated ultrasound examinations, for example, can cause skin changes and tumors. On the other hand, a chronic tumor disease represents a considerable psychological burden for patients. In most cases, however, a positive prognosis can be given for an insolinoma. If the tumor is detected early and the operation succeeds without complications, the patient can leave the hospital after a few days and is considered cured after a few follow-up visits. In patients with existing chronic diseases or other medical conditions, the prognosis depends on the constitution and individual symptoms.
Prevention
Since the causes for the development of insulinoma are not clear, there are also no measures that could be used to prevent this tumor.
Follow-up care
After the medical treatment of insulinoma, the aftercare begins. For this phase, the doctor has some useful recommendations for patients on how to support the therapy. Stress reduction and physical rest are particularly important. Chemotherapy is an extreme strain on the body, so patients need to rest afterwards. Gentle sports or other hobbies that offer a little variety are also suitable as compensation. The positive influence on well-being should not be underestimated here. In consultation with the responsible physician, those affected will find out which activities are okay. The organism may be too weak for certain undertakings. Those who suffer greatly from the therapy want psychotherapeutic support. Here the fears but also hopes of the patients come up. Coming to terms with the situation helps them to come to terms with it. Establishing contact with other sufferers also improves the quality of life. In addition, the self-help group promotes understanding. From the medical side, there is often useful advice for therapy and aftercare that is as free of complications as possible. In order to detect any changes, patients should keep a kind of diary to identify any side effects. They then clarify these at regular follow-up appointments with the doctor.
Here’s what you can do yourself
An insolinoma must always be treated by a doctor. Some self-help measures and home remedies support the medical therapy. As with other tumor diseases, gentleness applies to an insolinoma. Chemotherapy in particular can put a great deal of strain on the body, which is why those affected need appropriate compensation. Depending on the physical condition, this can be sports, a hobby or something else. The doctor can best answer which measures are permitted and which activities could harm the already weakened organism. Affected persons who suffer greatly from the tumor disease should also consult a therapist. Talking to a professional is the best way to work through the fears associated with a serious illness. Other affected persons or the responsible physician can also be asked for advice. To ensure complication-free treatment, possible side effects and interactions of the therapy measures should be recorded in a diary. The doctor can then adjust the treatment accordingly. After treatment has been completed, regular follow-up visits to the physician are indicated. If there are signs of recurrence, the physician must be informed immediately.
