Carcinoid syndrome is a rare and complex condition linked to neuroendocrine tumors (NETs). These tumors develop from specialized cells within the neuroendocrine system, and understanding the journey from diagnosis to treatment is crucial for patients and caregivers.

Understanding Neuroendocrine Tumors (NETs)

NETs begin when neuroendocrine cells divide rapidly, forming tumors that release excessive amounts of serotonin and other substances. This hormonal imbalance can lead to the symptoms of carcinoid syndrome. Interestingly, sometimes the first sign of an underlying NET is the presence of carcinoid syndrome.

How Common is Carcinoid Syndrome?

Carcinoid syndrome is not very common. Studies show that about 1 in 5 individuals with NETs experience carcinoid syndrome. NETs themselves are quite rare, affecting roughly 5 in 100,000 people in the United States.

Recognizing Carcinoid Syndrome Symptoms

The symptoms of carcinoid syndrome can vary widely but often include:

• Flushing of the head and neck
• Wheezing and shortness of breath
• Abdominal cramping and frequent, explosive diarrhea
• Foul-smelling, fatty stools
• Swelling in the feet and legs, possibly indicating heart failure
• Reduced interest in sex or erectile dysfunction
• Jaundice (yellowing of the skin and eyes)
• Dizziness or fainting
• A racing heart

Causes and Risk Factors

Carcinoid syndrome results from NETs in the gastrointestinal tract or lungs that release excessive hormones into the bloodstream. The primary risk factor is having a neuroendocrine tumor in these areas.

Complications

Carcinoid syndrome can lead to serious complications, such as carcinoid crises. These life-threatening events can be triggered by surgery, medical procedures, or trauma and include:

• Fluctuations in blood pressure
• Severe flushing
• Shortness of breath
• Confusion

Other complications include:

• Carcinoid heart disease, affecting the heart's chambers, valves, and blood vessels
• Mesenteric fibrosis, causing inflammation and scarring of the tissue connecting the intestines to the abdominal wall
• Depression, due to the body's impaired ability to metabolize tryptophan, essential for serotonin production

Diagnosing Carcinoid Syndrome

To diagnose carcinoid syndrome, healthcare providers use various tests:

• Urine tests to check hormone levels
• Physical exams and medical history reviews
• Blood tests to measure substances released by organs and tissues
• Neuroendocrine PET scans using Gallium 68 dotatate dye
• CT scans for detailed 3D images of organs and bones
• Ultrasounds for organ and bone visualization
• MRIs for internal body imaging
• Endoscopy, using a camera-equipped tube to look inside the body

Treatment Options

Treating carcinoid syndrome involves addressing the underlying NETs through:

• Surgery to remove or reduce tumor size
• Somatostatin analogs to regulate hormone production and slow tumor growth
• Targeted therapy focusing on specific genes or proteins
• Chemotherapy to destroy cancer cells
• Embolization to block blood vessels supplying the tumor

Living with Carcinoid Syndrome

Living with carcinoid syndrome requires self-care and medical attention.

Self-Care Tips:

• Flushing: Practice deep breathing, use cooling measures, get fresh air, and avoid alcohol.
• Wheezing: Drink herbal tea, use inhalers or vaporizers, and avoid smoking.
• Diarrhea: Consult healthcare providers for medications to manage diarrhea.

When to Seek Medical Attention:

• Worsening symptoms of carcinoid syndrome
• Any changes that may indicate NETs

Emergency Situations:

• Heart palpitations or chest pain
• Severe diarrhea
• Acute abdominal pain
• Fainting episodes
• Intense flushing

Questions for Your Healthcare Provider

When discussing carcinoid syndrome and NETs, consider asking:

• How can I confirm if I have a neuroendocrine tumor?
• Where is the tumor located?
• What are my treatment options?
• What side effects might I experience from treatment?
• Is a complete cure possible?
• Can carcinoid syndrome recur after treatment?