Carcinoid Tumors

A lung carcinoid tumor is a type of cancerous tumor that starts in the neuroendocrine cells in your lungs. Neuroendocrine cells help regulate many of your body’s functions, like moving food through your digestive tract and air through your lungs.

Typical lung carcinoid tumors — the most common kind — grow slowly and rarely spread (metastasize) to other parts of your body. Atypical lung carcinoid tumors tend to grow faster and are more likely to spread to other organs.

Carcinoid tumors can start in many parts of your body, including your digestive tract, appendix, kidneys and other organs. About 1 in 3 start in your lungs.

Typical carcinoid tumors

Typical carcinoid tumors account for up to 90% of lung carcinoid tumors. They’re slow-growing and don’t often metastasize elsewhere in your body. Typical carcinoid tumors can be central carcinoids (located in the large airways in your lungs) or peripheral carcinoids (found around the edges of your lungs and small airways).

Atypical carcinoid tumors

Atypical lung carcinoid tumors are much less common than typical lung carcinoids and tend to grow faster. They have a greater chance of spreading to other organs. They’re also more likely to be associated with smoking than typical carcinoids. Atypical lung carcinoid tumors are more often peripheral carcinoids, but they’re sometimes found in your large airways.

How common are lung carcinoid tumors?

Lung carcinoid tumors are rare. About 2,000 to 4,500 new cases of lung carcinoid tumors are diagnosed in the U. S. each year. Only 1% to 2% of all lung cancers are carcinoid tumors.