Insulinoma

What it is

From: Orphanet

A form of functioning pancreatic neuroendocrine tumor characterized most commonly by a solitary, small pancreatic lesion that causes hyperinsulinemic hypoglycemia.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormality of the pancreatic islet cells · Very frequent (99-80%)

An abnormality of the islet of Langerhans, i.e., of the regions of the pancreas that contain its endocrine cells. These are the alpha cells, which produce glucagon, the beta cells, which produce insulin and amylin, the delta cells, which produce somatostatin, the PP cells, which produce pancreatic polypeptide, and the epsilon cells, which produce ghrelin.

Fasting hyperinsulinemia · Very frequent (99-80%)

An increased concentration of insulin in the blood in the fasting state, i.e., not as the response to food intake.

Hyperhidrosis · Very frequent (99-80%)

Abnormal excessive perspiration (sweating) despite the lack of appropriate stimuli like hot and humid weather.

Hyperinsulinemia · Very frequent (99-80%)

An increased concentration of insulin in the blood.

Hyperinsulinemic hypoglycemia · Very frequent (99-80%)

An increased concentration of insulin combined with a decreased concentration of glucose in the blood.

Palpitations · Very frequent (99-80%)

A sensation that the heart is pounding or racing, which is a non-specific sign but may be a manifestation of arrhythmia.

Recurrent hypoglycemia · Very frequent (99-80%)

Recurrent episodes of decreased concentration of glucose in the blood.

Seizure · Very frequent (99-80%)

A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

Transient global amnesia · Very frequent (99-80%)

A paroxysmal, transient loss of memory function with preservation of immediate recall and remote memory but with a severe impairment of memory for recent events and ability to retain new information.

Tremor · Very frequent (99-80%)

An unintentional, oscillating to-and-fro muscle movement about a joint axis.

Nonketotic hypoglycemia · Very frequent (99-80%)

Atypical behavior · Frequent (79-30%)

Atypical behavior is an abnormality in a person's actions that can be controlled or modulated by the will of the individual. While abnormal behaviors can be difficult to control, they are distinct from other abnormal actions that cannot be affected by the individual's will.

Fluctuations in consciousness · Frequent (79-30%)

Changes in one's level of awareness and responsiveness to their environment.

Generalized muscle weakness · Frequent (79-30%)

Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature.

Other findings in the same source

From: Orphanet

Additional reported features include Increased body weight (Frequent (79-30%)); Pituitary prolactin cell adenoma (Frequent (79-30%)); Polyphagia (Frequent (79-30%)); Primary hyperparathyroidism (Frequent (79-30%)); Reactive hypoglycemia (Frequent (79-30%)); Reduced consciousness (Frequent (79-30%)); Zollinger-Ellison syndrome (Frequent (79-30%)); Abnormal rapid eye movement sleep (Occasional (29-5%)); Abnormality of higher mental function (Occasional (29-5%)); Abnormality of pain sensation (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

All ages

Inheritance in the source

From: Orphanet

Not applicable

Frequency and the population described

From: Orphanet

Annual incidence: 1-9 / 1 000 000; Ireland; Value and class. Annual incidence: 1-9 / 1 000 000; Worldwide; Value and class. Point prevalence: 1-9 / 1 000 000; Japan; Value and class. Point prevalence: Unknown; Europe; Class only.

Which doctor should you see?

The suggested department for discussing Insulinoma is Endocrinology, with a endocrinologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which hormone or metabolic finding is important in this case?
• How should test timing and current medicines be taken into account?
• What follow-up would show whether the care plan is working?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Insulinoma. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.