Small cell lung cancer

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Evidence last reviewed: 12 Jul 2026

Topic last updated: 28 Jul 2026

Small cell lung cancer (SCLC) is an aggressive malignancy that primarily affects older adult smokers. Approximately two-thirds of patients have evidence of distant metastasis at presentation.

Most common presenting symptoms are cough, chest pain, hemoptysis, dyspnea, and weight loss.

A suspicious lung mass should be biopsied during bronchoscopy or transthoracic needle aspiration.

Staging studies include chest/abdomen computed tomography (CT) and brain magnetic resonance imaging (preferred) or head CT, with mediastinoscopy and/or bone marrow aspirate and biopsy in selected cases.

Localized disease should be treated with concurrent chemotherapy and radiation therapy. Surgery should be offered to patients with clinical T1N0 or T2N0 disease after mediastinoscopy.

Prophylactic cranial irradiation should be considered for all patients with limited-stage disease. Extensive-stage disease should be treated with chemotherapy and immunotherapy.

Definition

Lung cancer comprises a group of malignant epithelial tumors arising from cells lining the lower respiratory tract. Lung cancer is divided into two histologic categories: SCLC and non-small cell lung cancer (NSCLC). SCLC tumor cells are small and densely packed, with scant cytoplasm, finely granular nuclear chromatin, and absence of nucleoli.[1]

SCLC accounts for approximately 11% to 13% of all lung cancers.[2][3]

History and exam

Key diagnostic factors

cough
dyspnea
hemoptysis
chest pain
weight loss

Full details

Other diagnostic factors

older age
male sex
fatigue
pulmonary exam abnormalities
hoarseness
confusion
personality changes
nausea and vomiting
headache
dysphagia
bone pain and/or fractures
seizures
cervical or supraclavicular adenopathy
facial swelling
dilated neck or chest/abdominal wall veins
finger clubbing
hypertrophic osteoarthropathy

Full details

Risk factors

cigarette smoking
environmental tobacco exposure
radon gas exposure
older age
chronic obstructive pulmonary disease
asbestos exposure
ambient air pollution
male sex

Full details

Diagnostic tests

1st tests to order

chest x-ray
contrast-enhanced CT chest, abdomen, and pelvis

Full details

Tests to consider

CBC
LFTs
renal function
blood urea nitrogen (BUN) and electrolytes
serum calcium
LDH
sputum cytology
pulmonary function tests
MRI head
FDG-PET/CT scan
bone scintigraphy scan
bone marrow aspiration/biopsy
flexible bronchoscopy
endobronchial ultrasound-guided biopsy
transthoracic needle aspiration biopsy
thoracentesis
pericardiocentesis
video-assisted thoracoscopic surgery
pathologic confirmation

Full details

Treatment algorithm

ACUTE

limited stage disease

extensive stage disease

ONGOING

relapsed or primary progressive disease

Contributors

Authors

Bingnan Zhang, MD, MBA

Assistant Professor

Department of Thoracic/Head and Neck Medical Oncology

Division of Cancer Medicine

The University of Texas MD Anderson Cancer Center

Houston, TX

Disclosures

BZ declares that she has no competing interests.

Acknowledgements

Dr Bingnan Zhang would like to gratefully acknowledge Dr Leena Gandhi, Dr Alvin R. Cabrera, Dr Christopher R. Kelsey, Dr Lawrence B. Marks, Dr Rebecca Suk Heist, and Dr Catherine B. Meador, previous contributors to this topic.

Disclosures

LG, ARC, CRK, and LBM declare that they have no competing interests. RSH has received honoraria for consulting from Novartis, Abbvie, Daichii Sankyo, and EMD Serono. RSH's institution (not RSH) has received research funding from Agios, Abbvie, Exelixis, Daichii Sankyo, Novartis, Lilly, Mirati, Corvus, Incyte, and Genentech Roche.

Peer reviewers

Alan Neville, MD

Professor

Assistant Dean

Undergraduate Program

McMaster University

Hamilton

Ontario

Canada

Disclosures

AN declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: small cell lung cancer [internet publication].Full text

Dingemans AC, Früh M, Ardizzoni A, et al. Small-cell lung cancer: ESMO clinical practice guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2021 Jul;32(7):839-53.Full text Abstract

National Institute for Health and Care Excellence. Lung cancer: diagnosis and management. Mar 2024 [internet publication].Full text

Simone CB 2nd, Bogart JA, Cabrera AR, et al. Radiation therapy for small cell lung cancer: an ASTRO clinical practice guideline. Pract Radiat Oncol. 2020 May - Jun;10(3):158-73.Full text Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials
- Non-small cell lung cancer
- Pneumonia/bronchitis
- Carcinoid tumor
More Differentials
Guidelines
- NCCN clinical practice guidelines in oncology: small cell lung cancer
- NCCN clinical practice guidelines in oncology: lung cancer screening
More Guidelines
Patient information
Lung cancer: questions to ask your doctor
Bronchoscopy
More Patient information
Videos
Pleural aspiration animated demonstration
Insertion of intercostal drain, Seldinger technique: animated demonstration
More videos
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Small cell lung cancer

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic tests

1st tests to order

Tests to consider

Treatment algorithm

limited stage disease

extensive stage disease

relapsed or primary progressive disease

Contributors

Authors

Bingnan Zhang, MD, MBA

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Alan Neville, MD

Disclosures

Peer reviewer acknowledgements

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials

Guidelines

Patient information

Videos

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice