Small cell lung cancer
Updates to Article Attributes
Small cell-cell lung cancer (SCLC), also known as oat cell-cell lung cancer, is a subtype of bronchogenic carcinoma and considered separate separated from non-small-cell lung cancer (NSCLC) as it has a unique presentation, imaging appearances, treatment, and prognosis. Small cell SCLCs are neuroendocrine tumours of the lung cancers that rapidly grow, are highly malignant, widely metastasise, and show, despite showing an initial response to chemotherapy and radiotherapy. Despite this, SCLCs have a poor prognosis and are usually unresectable.
Epidemiology
Small cell lung cancers represent 15-20% of lung cancers 1 and are strongly associated with cigarette smoking.
Clinical presentation
Clinical presentation can significanctlysignificantly vary and can present in the following ways:
- constitutional
- fever
- weight loss
- malaise
- primary tumour
- cough
- haemoptysis
- dyspnoea
- local invasion
- dysphagia (oesophageal compression)
- hoarseness
(recurrent(recurrent laryngeal nerve palsy) - stridor (airway compression)
- SVC obstruction
- rib erosion
- metastatic spread (affecting ~70% of patients are presentation)
- bone pain (bone metastases)
- focal neurological deficit
(CNS(CNS involvement) - right upper quadrant pain
(liver(liver metastases)
-
paraneoplastic syndromes
(see:bronchogenic carcinoma)
Pathology
Small cell carcinoma is considered a neuroendocrine tumour of the lung. It arises from the bronchial mucosa. Local invasion occurs in the submucosa with subsequent invasion of peribronchial connective tissue. Cells are small, oval, with scant cytoplasm and a high mitotic count.
It is the most common lung cancer subtype to produce necrosis, superior vena cava (SVC) infiltration/SVC obstruction, and paraneoplastic syndromes (see bronchogenic carcinoma).
Location
Approximately 90-95% of SCLCs occur centrally, and usually usually arising inadjacent to a lobar or main bronchus 3 3.
Radiographic features
Small cellAs previously mentioned, small-cell tumours are located centrally in the vast majority of cases (90%). They arise from main-stem of lobar bronchi and thus appear as hilar or perihilar masses 2. They, and frequently have mediastinal lymph node involvement at the presentation.
Plain radiograph
Appearances on chest x-rays are non-specific. They may be seen as a hilar/perihilar mass usually with mediastinal widening due to lymph node enlargement 2. In fact, the mediastinal involvement is often the most striking feature and the primary mass may be inapparent.
CT
On CT, mediastinal involvement may appear similar to lymphoma, with numerous enlarged nodes. Direct infiltration of adjacent structures is more common. Small cell carcinoma of the lung is the most common cause of SVC obstruction, due to both compression/thrombosis and/or direct infiltration 2.
NecrosisSCLCs are usually characterised as a mass lesion, where necrosis and haemorrhage are both common. Only rarely do small cell carcinomasthey present as a solitary pulmonary nodule.
CT is ableFor tumour staging, please refer to the article on IASLC (International Association for the timeStudy of diagnosis. Initially, the TNM system of staging was not used. It was traditionally divided using a two-stage system, i.e. limited and extensive (see small cellLung Cancer) 8th edition lung cancer staging system).
Limited disease is treated using combined chemotherapy and radiotherapy with a 5-year survival rate of ~20%. Extensive disease is treated with palliative chemotherapy and supportive care with a 2-year survival rate of 20%.
Since (Since 2013, small cell lung cancer is staged the same way as non-small cell lung cancer).
Treatment and prognosis
Most cases will present in advanced stages, not operable, and with a dismal prognosis. Only about 5% of patients present at an early stage (Ia, Ib, or IIa), with a potentially curable disease. These patients are usually managed with an aggressive chemo-radiation therapy and, selected ones, with lobectomy associated with mediastinal lymph node dissection 4,5.
Surgical excision is commonly not recommended beyond these early stages, as studies have shown that any nodal involvement (N1–3 disease) will not benefit from the excisional treatment 4,5.
Brain metastases are found in up to a quarter of patients at presentation 4 and are known as a common site of disease recurrence after an initial treatment response. Prophylactic cerebral irradiation (PCI) can be offered for those with adequate systemic control and without metastases to the CNS 4.
Advanced disease (stage IV) is managed only with chemotherapy aiming for palliation and symptoms control.
Differential diagnosis
Imaging differential considerations include:
- non-small-cell lung cancer
- lymphoma
- pulmonary sarcoma (rare)
- pulmonary metastases
- benign lung lesions
See also
-<p><strong>Small cell lung cancer (SCLC)</strong>, also known as <strong>oat cell lung cancer</strong>, is a subtype of <a href="/articles/lung-cancer-3">bronchogenic carcinoma</a> and considered separate from <a href="/articles/non-small-cell-lung-cancer">non-small-cell lung cancer (NSCLC)</a> as it has a unique presentation, imaging appearances, treatment, and prognosis. Small cell lung cancers rapidly grow, are highly malignant, widely metastasise and show an initial response to chemotherapy and radiotherapy. Despite this, SCLCs have a poor prognosis and are usually unresectable.</p><h4>Epidemiology</h4><p>Small cell lung cancers represent 15-20% of lung cancers <sup>1</sup> and are strongly associated with cigarette smoking.</p><h4>Clinical presentation</h4><p>Clinical presentation can significanctly vary and can present in the following ways:</p><ul>- +<p><strong>Small-cell lung cancer (SCLC)</strong>, also known as <strong>oat-cell lung cancer</strong>, is a subtype of <a href="/articles/lung-cancer-3">bronchogenic carcinoma</a> separated from <a href="/articles/non-small-cell-lung-cancer-2">non-small-cell lung cancer (NSCLC)</a> as it has a unique presentation, imaging appearances, treatment, and prognosis. SCLCs are <a href="/articles/neuroendocrine-tumour-of-the-lung">neuroendocrine tumours of the lung</a> that rapidly grow, are highly malignant, widely metastasise, and, despite showing an initial response to chemotherapy and radiotherapy, have a poor prognosis and are usually unresectable.</p><h4>Epidemiology</h4><p>Small cell lung cancers represent 15-20% of lung cancers <sup>1</sup> and are strongly associated with cigarette smoking.</p><h4>Clinical presentation</h4><p>Clinical presentation can significantly vary and can present in the following ways:</p><ul>
-<li>hoarseness (recurrent laryngeal nerve palsy)</li>- +<li>hoarseness (<a href="/articles/recurrent-laryngeal-nerve">recurrent laryngeal nerve</a> palsy)</li>
-<li>focal neurological deficit (CNS involvement)</li>-<li>right upper quadrant pain (liver metastases)</li>- +<li>focal neurological deficit (<a href="/articles/brain-metastases">CNS involvement</a>)</li>
- +<li>right upper quadrant pain (<a href="/articles/hepatic-metastases-1">liver metastases</a>)</li>
- +<li><a href="/articles/paraneoplastic-syndromes">paraneoplastic syndromes</a></li>
- +</ul><h4>Pathology</h4><p>Small cell carcinoma is considered a <a href="/articles/neuroendocrine-tumour-of-the-lung">neuroendocrine tumour of the lung</a>. It arises from the bronchial mucosa. Local invasion occurs in the submucosa with subsequent invasion of peribronchial connective tissue. Cells are small, oval, with scant cytoplasm and a high mitotic count. </p><p>It is the most common lung cancer subtype to produce necrosis, superior vena cava (SVC) infiltration/<a href="/articles/superior-vena-cava-obstruction">SVC obstruction</a>, and paraneoplastic syndromes (see <a href="/articles/lung-cancer-3">bronchogenic carcinoma</a>).</p><h5>Location</h5><p>Approximately 90-95% of SCLCs occur centrally, usually arising adjacent to a lobar or main bronchus<sup> 3</sup>.</p><h4>Radiographic features</h4><p>As previously mentioned, small-cell tumours are located centrally in the vast majority of cases. They arise from main-stem of lobar bronchi and thus appear as hilar or perihilar masses <sup>2</sup>, and frequently have mediastinal lymph node involvement at the presentation.</p><h5>Plain radiograph</h5><p>Appearances on chest x-rays are non-specific. They may be seen as a hilar/perihilar mass usually with mediastinal widening due to lymph node enlargement <sup>2</sup>. In fact, the mediastinal involvement is often the most striking feature and the primary mass may be inapparent.</p><h5>CT</h5><p>On CT, mediastinal involvement may appear similar to lymphoma, with numerous enlarged nodes. Direct infiltration of adjacent structures is more common. Small cell carcinoma of the lung is the most common cause of <a href="/articles/superior-vena-cava-obstruction">SVC obstruction</a>, due to both compression/thrombosis and/or direct infiltration <sup>2</sup>. </p><p>SCLCs are usually characterised as a mass lesion, where necrosis and haemorrhage are both common. Only rarely they present as a <a href="/articles/solitary-pulmonary-nodules">solitary pulmonary nodule</a>.</p><p>For tumour staging, please refer to the article on <a href="/articles/lung-cancer-staging-iaslc-8th-edition">IASLC (International Association for the Study of Lung Cancer) 8th edition lung cancer staging system</a> (Since 2013, small cell lung cancer is staged the same way as non-small cell lung cancer). </p><h4>Treatment and prognosis</h4><p>Most cases will present in advanced stages, not operable, and with a dismal prognosis. Only about 5% of patients present at an early stage (Ia, Ib, or IIa), with a potentially curable disease. These patients are usually managed with an aggressive chemo-radiation therapy and, selected ones, with lobectomy associated with mediastinal lymph node dissection <sup>4,5</sup>. </p><p>Surgical excision is commonly not recommended beyond these early stages, as studies have shown that any nodal involvement (N1–3 disease) will not benefit from the excisional treatment <sup>4,5</sup>.</p><p><a href="/articles/brain-metastases">Brain metastases</a> are found in up to a quarter of patients at presentation <sup>4</sup> and are known as a common site of disease recurrence after an initial treatment response. Prophylactic cerebral irradiation (PCI) can be offered for those with adequate systemic control and without metastases to the CNS <sup>4</sup>. </p><p>Advanced disease (stage IV) is managed only with chemotherapy aiming for palliation and symptoms control. </p><h4>Differential diagnosis</h4><p>Imaging differential considerations include:</p><ul>
-<a href="/articles/paraneoplastic-syndromes">paraneoplastic syndromes</a> (see: <a href="/articles/lung-cancer-3">bronchogenic carcinoma</a>)</li>-</ul><h4>Pathology</h4><p>Small cell carcinoma is considered a <a href="/articles/neuroendocrine-tumour-of-the-lung">neuroendocrine tumour of the lung</a>. It arises from the bronchial mucosa. Local invasion occurs in the submucosa with subsequent invasion of peribronchial connective tissue. Cells are small, oval, with scant cytoplasm and a high mitotic count. </p><p>It is the most common lung cancer subtype to produce necrosis, superior vena cava (SVC) infiltration/<a href="/articles/superior-vena-cava-obstruction">SVC obstruction</a>, and paraneoplastic syndromes (see <a href="/articles/lung-cancer-3">bronchogenic carcinoma</a>).</p><h5>Location</h5><p>Approximately 90-95% of SCLCs occur centrally, and usually arising in a lobar or main bronchus<sup> 3</sup>.</p><h4>Radiographic features</h4><p>Small cell tumours are located centrally in the vast majority of cases (90%). They arise from main-stem of lobar bronchi and thus appear as hilar or perihilar masses <sup>2</sup>. They frequently have mediastinal lymph node involvement at presentation.</p><h5>Plain radiograph</h5><p>Appearances on chest x-rays are non-specific. They may be seen as a hilar/perihilar mass usually with mediastinal widening due to lymph node enlargement <sup>2</sup>. In fact, the mediastinal involvement is often the most striking feature and the primary mass may be inapparent.</p><h5>CT</h5><p>On CT mediastinal involvement may appear similar to lymphoma, with numerous enlarged nodes. Direct infiltration of adjacent structures is more common. Small cell carcinoma of the lung is the most common cause of SVC obstruction, due to both compression/thrombosis and/or direct infiltration <sup>2</sup>. </p><p>Necrosis and haemorrhage are both common. Only rarely do small cell carcinomas present as a <a href="/articles/solitary-pulmonary-nodules">solitary pulmonary nodule</a>.</p><p>CT is able to <a href="/articles/small-cell-lung-cancer-staging-1">stage small cell lung cancer</a>.</p><h4>Treatment and prognosis</h4><p>Small cell lung cancer is rarely operable at the time of diagnosis. Initially, the TNM system of staging was not used. It was traditionally divided using a two-stage system, i.e. limited and extensive (see <a href="/articles/small-cell-lung-cancer-staging-1">small cell lung cancer staging</a>).</p><p>Limited disease is treated using combined chemotherapy and radiotherapy with a 5-year survival rate of ~20%. Extensive disease is treated with palliative chemotherapy and supportive care with a 2-year survival rate of 20%.</p><p>Since 2013 small cell lung cancer is staged the same way as non-small cell lung cancer.</p><h4>Differential diagnosis</h4><p>Imaging differential considerations include:</p><ul>-<li>-<a href="/articles/non-small-cell-lung-cancer">non-small-cell lung cancer</a><ul>- +<a href="/articles/non-small-cell-lung-cancer-2">non-small-cell lung cancer</a><ul>
-<li><a href="/articles/benign-lung-lesions">benign lung lesions</a></li>-</ul><h4>See also</h4><ul>-<li><a href="/articles/lung-cancer-3">bronchogenic carcinoma</a></li>-<li><a href="/articles/small-cell-lung-cancer-staging-1">staging of small cell lung cancer</a></li>- +<li><a href="/articles/benign-lung-lesions">benign lung lesions </a></li>
References changed:
- 4. Alvarado-Luna G & Morales-Espinosa D. Treatment for Small Cell Lung Cancer, Where Are We Now?-A Review. Transl Lung Cancer Res. 2016;5(1):26-38. <a href="https://doi.org/10.3978/j.issn.2218-6751.2016.01.13">doi:10.3978/j.issn.2218-6751.2016.01.13</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/26958491">Pubmed</a>
- 5. Schneider B, Saxena A, Downey R. Surgery for Early-Stage Small Cell Lung Cancer. J Natl Compr Canc Netw. 2011;9(10):1132-9. <a href="https://doi.org/10.6004/jnccn.2011.0094">doi:10.6004/jnccn.2011.0094</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/21975913">Pubmed</a>
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