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Roman L Kleynberg, MD
UC Irvine Medical Center
Orange, CA
Disclosure: Roman L Kleynberg, MD, has disclosed no relevant financial relationships.
Vi K Chiu, MD, PhD
UC Irvine Medical Center
Orange, CA
Disclosure: Vi K Chiu, MD, PhD, has disclosed no relevant financial relationships.
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Roman L Kleynberg, MD; Vi K Chiu, MD, PhD | June 25, 2015
Small cell lung cancer (SCLC), previously known as oat cell carcinoma, is considered distinct from other lung cancers, which are called non–small cell lung cancers (NSCLCs), on the basis of their clinical and biologic characteristics. This high-power field photomicrograph, stained with hematoxylin and eosin (H&E), displays SCLC on the left side, with normal respiratory epithelium on the right side.
Which of the following statements about SCLC is not true?
Image courtesy of Medscape.
Answer: D. Small cell carcinomas originate only in the lung.
Although the majority (~95%) of SCLCs do originate in the lungs, the remainder can arise from extrapulmonary structures, such as the nasopharynx, the gastrointestinal (GI) tract, and the genitourinary (GU) tract. Lung cancer can originate in the bronchi, bronchioles, and alveoli (shown).
Image courtesy of American Cancer Society.
A substantial increase in US cigarette consumption in the first half of the 20th century led to a corresponding increase in deaths from lung cancer after a lag time in the range of 20 years. The graph in this slide illustrates the increase in cigarette consumption in the United States (expressed in terms of cigarettes smoked per person per year) and the associated rise in lung cancer mortality (expressed in terms of deaths per 100,000 people) from the 1900s into the 1970s.
Image courtesy of Wikimedia Commons.
For SCLC as well as NSCLC, clinical staging according to the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) system is helpful in estimating the prognosis.[1]
For full staging of SCLC, which of the following is/are not necessary?
Image courtesy of Wikimedia Commons.
Answer: F. None of the above; all are necessary.
All of the steps listed in answers A, B, C, D, and E are required for full lung cancer staging. In addition, mediastinoscopy may be required, as well as bone marrow biopsy and bone scanning to differentiate limited-stage from extensive-stage disease. This broader distinction between limited-stage and extensive-stage disease (shown) is commonly employed to guide treatment of SCLC.[2]
Lung cancer comprises several histologic subtypes, which are associated with differing management approaches and prognoses.[3] The pie chart in this slide depicts these histologic subtypes and their relative frequency; in addition, it further divides each group of patients into nonsmokers and smokers, as defined by a current history, a former history of smoking, or a 1-year history of smoking.
Image courtesy of Wikimedia Commons. Data from Kenfield SA et al.[3]
The scanning electron micrograph in this slide shows a lung cancer cell dividing.
Which of the following statements regarding SCLC is not true?
Image courtesy of Wikimedia Commons.
Answer C. SCLC is associated with mutations, such as exon 19 deletion, exon 21 substitution, and epidermal growth factor receptor (EGFR) mutation.
Such mutations are more commonly associated with NSCLC. The brain is a common site of spread for SCLC. This slide shows a contrast-enhanced axial MRI scan of the brain of a patient known to have SCLC; two ring-enhancing lesions are visible in the periventricular region.
Image courtesy of Medscape.
The bones are a common site for spread in SCLC. This slide shows a whole-body bone scan from a patient with SCLC, with anterior and posterior views. Radiotracer uptake is visible in the spine, the ribs, the left scapula, and the pelvis, indicating metastatic bony disease.
Which of the following statements is not true?
Image courtesy of Medscape.
Answer: A. Between 30% and 40% of patients with SCLC have disseminated or extensive-stage disease on presentation.
As noted on slide 6, approximately two thirds of patients with SCLC have extensive-stage disease on presentation.
This slide shows a CT scan at the level of the hilum from a patient with SCLC. A large hilar tumor can be seen on the right side, as well as pleural thickening, indicative of pleural metastasis. A loculated pleural effusion is also visible adjacent to the tumor mass in association with an atelectatic lung.
Image courtesy of Medscape.
Progression of SCLC can cause increased pressure on the mediastinal structures, which can lead to further complications.[5]
Which of the following may develop as a result of this increased pressure on the mediastinal structures?
Image courtesy of Wikimedia Commons.
Answer: F. All of the above.
The adrenal glands are also a common site of spread for SCLC. This slide shows a nonenhanced CT scan of the abdomen at the level of the adrenals. A large left adrenal mass with associated hypoattenuation can be seen. In a patient with SCLC, this finding is likely to represent metastatic disease.
Image courtesy of Medscape.
This slide shows a contrast-enhanced axial CT scan from a patient with known SCLC. Innumerable hypoattenuating liver lesions are present. In view of the history of SCLC, the hypoattenuating liver lesions, and the indistinct borders of the liver lesions, it is very likely that this patient has metastatic SCLC.
With respect to limited-stage SCLC, which of the following statements is not true?
Image courtesy of Medscape.
Answer: A. Limited-stage SCLC should fit within two radiation "ports."
As noted on slide 6, limited-stage disease should fit within one radiation field.[2]
This slide shows a coronal PET scan from a patient with SCLC. Increased uptake is visible in the left hilum and the left adrenal; this probably represents metastatic SCLC.
Image courtesy of Medscape.
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