Functioning Carcinoid: A Comprehensive Guide

Introduction

Functioning carcinoid, also known as carcinoid syndrome, is a rare neuroendocrine tumor (NET) characterized by the production of excess serotonin and other vasoactive substances. These substances can cause a variety of symptoms, including flushing, diarrhea, wheezing, and heart valve damage.

While functioning carcinoids can occur anywhere in the body, they are most commonly found in the gastrointestinal tract (gut), pancreas, and lungs. The most common type of functioning carcinoid is the midgut carcinoid, which occurs in the small intestine.

Symptoms

The symptoms of functioning carcinoid can vary depending on the location of the tumor and the amount of serotonin and other vasoactive substances that are being produced. The most common symptoms include:

• Flushing: This is the most common symptom of functioning carcinoid. Flushing is a sudden, intense redness of the face, neck, and chest. It can be accompanied by a feeling of warmth or burning.
• Diarrhea: Diarrhea is another common symptom of functioning carcinoid. It can be watery or loose, and it may be accompanied by abdominal pain and cramping.
• Wheezing: Wheezing is a high-pitched whistling sound that occurs when the airways are narrowed. It can be a sign of carcinoid heart disease, which is a condition that can develop in people with functioning carcinoids.
• Heart valve damage: Carcinoid heart disease can damage the heart valves, leading to regurgitation (leaking) of blood. This can cause shortness of breath, fatigue, and swelling in the legs and feet.

Other symptoms of functioning carcinoid can include:

• Abdominal pain
• Nausea and vomiting
• Weight loss
• Skin changes
• Increased sweating
• Headaches
• Dizziness

Diagnosis

The diagnosis of functioning carcinoid can be challenging, as the symptoms can be similar to those of other conditions. Your doctor will likely start by asking you about your symptoms and medical history. They may also perform a physical examination and order blood tests and imaging tests.

Blood tests can be used to measure the levels of serotonin and other vasoactive substances in your blood. Imaging tests can be used to locate the tumor and determine its size and extent.

Treatment

The treatment for functioning carcinoid depends on the location and stage of the tumor, as well as the severity of the symptoms. Treatment options may include:

• Surgery: Surgery is the primary treatment for functioning carcinoid. The goal of surgery is to remove the tumor and any affected lymph nodes.
• Radiation therapy: Radiation therapy can be used to shrink tumors and relieve symptoms.
• Chemotherapy: Chemotherapy is a type of drug treatment that can be used to kill cancer cells.
• Targeted therapy: Targeted therapy is a type of drug treatment that targets specific molecules on cancer cells.
• Somatostatin analogs: Somatostatin analogs are drugs that can help to reduce the production of serotonin and other vasoactive substances.

Prognosis

The prognosis for functioning carcinoid depends on the location and stage of the tumor, as well as the severity of the symptoms. The overall 5-year survival rate for people with functioning carcinoid is about 60%. However, the survival rate is higher for people with early-stage tumors that are located in the gastrointestinal tract.

Conclusion

Functioning carcinoid is a rare but serious condition. The symptoms of functioning carcinoid can be debilitating, but there are a variety of treatment options available. If you are experiencing any of the symptoms of functioning carcinoid, it is important to see your doctor right away.