Types of lung NETs

There are 4 different types of neuroendocrine tumours (NETs) of the lung. Some lung NETs are called carcinoid tumours.

The type of lung NET you have depends on which neuroendocrine cell the tumour started in. Knowing this helps your doctor decide which treatment you need.

Primary and secondary cancer

A NET that starts in the lung is called a primary lung NET. A cancer that spreads to your lung from somewhere else in your body is a secondary lung cancer. Secondary cancers are also called metastases.

This is important because the primary cancer tells your doctor which type of treatment you need. The information on this page is about primary lung NETs.

Functioning and non functioning tumours

Some lung NETs make hormones and cause hormone related symptoms. Doctors call these functioning tumours (F-NETs). Those that don’t make hormones are non functioning tumours (NF-NETs).

More than 9 in every 10 NETs of the lung (90%) are non functioning tumours.


There are 4 types of lung NETs:

  • small cell lung cancer (SCLC)
  • large cell neuroendocrine carcinoma (LCNEC)
  • typical carcinoid (TC)
  • atypical carcinoid (AC)

Small cell lung cancer (SCLC)

Around 15 to 20 out of every 100 lung cancers (around 15 - 20%) diagnosed are this type. It is usually caused by smoking. SCLC tends to spread quickly early on.

Large cell neuroendocrine carcinoma (LCNEC)

Around 3 out of every 100 lung cancers (3%) diagnosed in the UK every year are large cell neuroendocrine carcinomas. They are usually caused by smoking.

Typical carcinoid (TC)

Typical carcinoids are also called carcinoid tumours. About 2 in every 100 lung cancers (2%) diagnosed in the UK every year are typical carcinoids.

TCs usually grow slowly over some years. They rarely spread outside the lungs.

Atypical carcinoid (AC)

Atypical carcinoids are also called carcinoid tumours. Fewer than 1 in every 100 lung cancers (1%) diagnosed in the UK every year are atypical carcinoids.

ACs usually grow quicker and are more likely to spread than typical carcinoids. They often spread to the liver and bones.


DIPNECH stands for diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. It’s a very rare condition where the neuroendocrine cells of the lung start to grow in an uncontrolled way.

Researchers think that in some people these cells develop into a typical or atypical carcinoid. Some doctors call DIPNECH a pre cancer. The abnormal cells are all contained within the lining of the lung and have not spread.


The type of the lung NET helps your doctor decide which treatment you need. Treatment also depends on:

  • the stage of the lung NET
  • where the tumour is
  • other health conditions you may have
  • Latest advances in management of small cell lung cancer and other neuroendocrine tumors of the lung
    Hussein A. Assia and Sukhmani K. Paddab
    Cancer Treatment and Research Communications 23 (2020) 

  • Lung and thymic carcinoids: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up
    E Baudin and others
    Annals of Oncology, 2021. Volume 32, Issue 4 

  • Neuroendocrine tumours of the lung: current challenges and advances in the diagnosis and management of well-differentiated disease
    A E Hendifar and others
    Journal of thoracic oncology, 2016. Vol 12, Issue 3, Pages 425-436

  • Pulmonary neuroendocrine (carcinoid) tumors: European Neuroendocrine Tumor Society expert consensus and recommendations for best practice for typical and atypical pulmonary carcinoids
    M E Caplin and others
    Annals of oncology, 2015. Vol 26, Issue 8, Pages 1604-1620

  • Small-cell lung cancer (SCLC): ESMO clinical practice guidelines for diagnosis, treatment and follow up
    M Fruh and others
    Annals of oncology, 2013. Vol 24, Supplement 6, Pages 99-105

  • Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia syndrome
    G Rossi and others
    European respiratory journal, 2016. Vol 47, Pages 1829-1841

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
26 Mar 2021
Next review due: 
26 Mar 2024

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