A lung carcinoid tumor — or pulmonary carcinoid tumor — is a rare type of lung cancer. Carcinoids are tumors that develop from neuroendocrine cells found in different parts of the body, such as the lungs and digestive tract.

There are two types of lung carcinoid tumors: typical and atypical.

Typical lung carcinoid tumors are a slow-growing type of cancer that are not associated with smoking and do not tend to spread beyond the lungs.

Some people do not experience symptoms, but shortness of breath, facial flushing, weight gain, and high blood pressure may develop due to hormonal involvement.

Atypical carcinoid tumors are more likely to spread and may be linked to smoking.

The main treatment for lung carcinoid tumors is surgery, but a doctor may also recommend chemotherapy, radiation therapy, or both.

This article will look at the symptoms, stages, and treatment of lung carcinoid tumors.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Bronchoscopy equipment used to diagnose carcinoid lung cancer tumorsShare on Pinterest
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Lung carcinoid tumors — also known as pulmonary carcinoid tumors or lung neuroendocrine tumors — are a type of lung cancer that doctors sometimes call lung carcinoids. They are a rare, slow-growing type of lung cancer.

People start developing carcinoid lung tumors in a certain type of body cell called a neuroendocrine cell.

Neuroendocrine cells found in the lungs are like nerve cells found in the brain and spinal cord. They also act like hormone-making cells.

Neuroendocrine cells are not part of a single organ but are spread across different parts of the body. Within the lungs, neuroendocrine cells:

  • help control air and blood flow
  • help control the growth of other lung cells
  • detect oxygen and carbon dioxide levels in inhaled air and release chemicals to help the lungs adjust

While there are different types of lung cancers, only cancers that develop from neuroendocrine cells in the lungs are called lung carcinoids.

Doctors have identified two types of lung carcinoid tumors: typical and atypical carcinoids.

About 25% of people with carcinoid lung tumors may not experience any symptoms. Doctors may find the cancer when testing a person for another medical condition.

Symptoms of carcinoid lung tumors may include:

  • coughing or wheezing
  • blood in phlegm
  • symptoms of pneumonia
  • facial flushing
  • shortness of breath
  • high blood pressure
  • weight gain
  • asthma-like symptoms
  • excessive growth in females of dark or coarse hair in a male pattern

According to the American Cancer Society, typical carcinoid tumors are the most common type of lung carcinoid tumors. Smoking does not seem to cause typical carcinoids in the lung.

Typical carcinoids grow slowly and do not usually spread beyond the lungs. They are considered stage 1a, low-grade because they do not spread easily.

Atypical carcinoids grow faster than typical carcinoids and may spread to other body organs. They develop more commonly in people who smoke compared with typical carcinoid lung tumors.

Doctors consider atypical carcinoids to be intermediate-grade tumors because of the risk of spreading.

Doctors use the tumor-node-metastasis (TNM) staging system to determine the progression of atypical lung carcinoids. This combines factors such as the size of the tumor and how far cancer has spread.

FeatureConsiderationsWhat to expect
TumorHow large is the tumor and has it grown into nearby tissue?If cancer has not spread, a person may have no symptoms and treatment is often effective.
NodeHas cancer spread to the lymph nodes?As this starts to happen, a person may be able to feel swelling in the lymph nodes around the collarbone.
MetastasisHas cancer spread to more distant parts of the body, such as the liver or bones?Jaundice, joint pain, and other symptoms may arise as cancer spreads.

According to the American Cancer Society, researchers are unsure what causes carcinoid lung tumors.

Many of the factors that lead to more common lung cancer, called carcinomas, do not seem to cause carcinoid tumors.

Doctors may find early signs of carcinoid lung tumors when doing lung biopsies for other medical conditions.

“Tumorlets” in the lungs are small clusters of neuroendocrine cells that resemble lung carcinoid tumors. Most often, tumorlets do not develop into carcinoid tumors, but sometimes they do.

Researchers have identified certain alterations in chromosomes and genes of cells in carcinoid lung tumors that may affect how the cells function. It is not yet clear how these changes lead to tumor development.

Doctors are also unsure whether certain risk factors exist for lung carcinoid development. Some people who develop lung carcinoid tumors may not have any risk factors to explain their condition.

Risk factors for carcinoid lung tumors include:

  • being female
  • being white
  • being aged between 45–55 years old
  • having multiple endocrine neoplasia type 1, an inherited disease that puts people at risk for tumors in endocrine organs
  • having a family history of lung carcinoid tumors
  • tobacco smoke (for atypical carcinoids)
  • exposure to certain air pollutants and chemicals

Many of these risk factors are things that people cannot change.

Since doctors are unsure of the causes and risk factors of carcinoid tumors, it is unknown how to prevent this type of cancer.

Since about one-quarter of people with carcinoid lung tumors do not have any symptoms, doctors must use other tools to diagnose them.

Doctors will check for unusual hormonal features if they suspect a neuroendocrine tumor.

These include:

  • urinary dU-5-hydroxy indol-acetic acid
  • 24-hour urine free cortisol
  • blood cortisol
  • adrenocorticotropic hormone in people with Cushing’s disease
  • growth hormone-releasing hormone and insulin growth factor in people with acromegaly

Bronchoscopy and biopsy are the gold standard for diagnosing carcinoid lung tumors. Bronchoscopy allows doctors to see the inside of the lungs. If a doctor detects an unusual growth, they can remove a sample for analysis.

Medical imaging can also help detect carcinoid lung tumors. According to a 2021 article, a chest X-ray may detect around 40% of carcinoid lung tumors. A CT scan or a PET scan may be more sensitive to these tumors.

When diagnosing carcinoid lung tumors, doctors must distinguish between typical and atypical tumors. This distinction is necessary for selecting the correct treatment.

People with lung carcinoids will need surgery to remove the tumor. For people with atypical carcinoids, this may be extensive. Surgeons may need to remove an entire lung.

Some people may need bronchoplasty, which involves repairing the bronchi of the lungs.

Additional therapy for advanced atypical lung carcinoids may include chemotherapy with or without radiation therapy.

Certain cancer societies also recommend additional therapy for atypical carcinoids with lymph node involvement.

According to a 2021 article, the most important factor that affects the outlook of carcinoid lung tumors is whether the cancer is typical or atypical.

Atypical lung carcinoids are more likely to spread to other parts of the body than typical lung carcinoids.

Other factors affecting the outlook are:

  • older age
  • where the tumor has spread
  • the stage at diagnosis
  • sex, as the outlook tends to be better for females

The relative chance of living at least another 5 years after a diagnosis of atypical carcinoids is 60%, while for typical carcinoids it is 90%.

Here are some questions people often ask about lung or pulmonary carcinoid tumors.

How serious is a carcinoid lung tumor?

A typical carcinoid lung tumor is considered low-stage and low-grade, as it tends to grow slowly. An atypical carcinoid lung tumor, however, can spread more rapidly. Without treatment, it can be fatal.

What is the survival rate of carcinoid lung cancer?

The relative chance of living at least another 5 years after a diagnosis of atypical carcinoids is 60%, while for typical carcinoids it is 90%.

Are lung carcinoid tumors curable?

Typical lung carcinoids grow very slowly and often respond to minor surgery. Low-grade and small tumors often need only regular monitoring to ensure the tumor has not spread.

Atypical carcinoids, however, can be harder to resolve, particularly with a later-stage diagnosis.

Is a carcinoid tumor in the lung considered lung cancer?

Lung carcinoid tumors — also called pulmonary carcinoid tumors or neuroendocrine tumors — are a type of lung cancer.

Lung carcinoid tumors develop from changes in neuroendocrine cells in the lungs. They may be typical or atypical.

Typical lung carcinoids are more common, and most do not spread outside the lungs. Atypical tumors may grow more quickly and spread to other parts of the body.

Doctors will diagnose carcinoid lung tumors using biopsies, blood and urine samples, and medical imaging. Once diagnosed, people may require surgery to remove the growth. Some doctors may recommend additional treatment.