CT findings of small cell lung carcinoma

Abstract

The purpose of this study was to clarify the recognizable computed tomography (CT) features of small cell lung carcinoma (SCLC).Contrast enhanced CT scans were reviewed retrospectively for mass location, mediastinal extension, and other concomitant findings in 142 patients with pathologically proven SCLC. SCLC was classified into hilar mass only (type I), hilar mass with ipsilateral mediastinal extension (type II), hilar mass with bilateral mediastinal extension (type III), and peripheral mass (type IV). When mediastinal lymphadenopathy (m-LAP) was indistinguishable from a hilar mass, we defined it as a mediastinal conglomerate mass (m-CM). Type IIa or IIIa had ipsilateral or bilateral m-LAP and type IIb, IIIb or IIIc had ipsilateral or bilateral m-CM.Type I (n = 8, 5.6%), type II (n = 58, 40.8%), type III (n = 55, 38.8%), and type IV (n = 21, 14.8%) were manifested. The combination of a hilar mass and m-CM was found in 68 patients (47.9%). Type IV masses showed lobulation in 11, microlobulation in 4, both lobulated and irregular margins in 4, and spiculation in 2. A total of 120 patients (84.5%) had a bronchial stenosis/obstruction; single (n = 52) and 2 or more (n = 68). Ninety-five patients (67.0%) had vascular invasion including main/lobar pulmonary artery and superior vena cava, and 55 (38.7%) had pleural effusion and/or pleural nodules. Concomitant parenchymal findings (n = 92, 64.8%) were noted: contiguous consolidation/nodule (n = 45), hematogeneous spread (n = 32), lymphangitic spread (n = 21), obstructive pneumonia (n = 22), and obstructive atelectasis (n = 14).In conclusion, the recognizable CT features of SCLC were a hilar mass with m-CM. Most of the hilar masses showed 2 or more bronchial stenoses/obstructions. Most cases of peripheral SCLC manifested as a lobulated mass rather than a spiculated mass. Vascular invasion and concomitant parenchymal findings were observed commonly.

Computed tomography-based differentiation of primary pulmonary lymphoepithelioma-like carcinoma and small-cell lung cancer

“… 2 , 6 , 10 , 12 , 13 LELC and SCLC tumors of a relatively large size are situated centrally more frequently, and they are often characterized by the encasement or involvement of vessels and bronchi. 2 , 6 , 10 , 12 , 13 , 19 – 21 Regarding SCLC, less than 5% of patients analyzed in previous studies had peripheral nodules with well-defined margins and homogeneous enhancement without associated lymphadenopathy on contrast-enhanced CT images, and most of these tumors were of an early stage. 20 , 33 In the present study, we matched the patients with SCLC to the patients with LELC based on the tumor stage of LELC, and a greater proportion of the patients with SCLC were in the early stage; accordingly, the proportion of peripherally located SCLC (28.0%) was also larger in our study as compared with real practice.…”

“… 15 – 18 Similar to those of LELC, common CT findings of SCLC include a centrally located tumor with lymphadenopathy. 19 – 21 However, SCLC is more aggressive than NSCLC and is associated with a poor prognosis. 16 , 22 …”

Small cell lung cancer mimicking lymphoma in CT and 68Ga-DOTA-NOC PET/CT

“…[ 1 , 2 , 8 ] All pulmonary neuroendocrine neoplasm include typical carcinoid, which is a low-grade malignancy, atypical carcinoid, which is a medium-grade malignancy, and large cell neuroendocrine carcinoma and SCLC, which are high-grade malignancies. [ 2 , 9 ] SCLC accounts for 15% to 20% of all lung cancers and is the most common pulmonary neuroendocrine neoplasm. [ 8 ] SCLC is well known to be closely associated with smoking and is more aggressive than nonsmall cell lung carcinoma (NSCLC) due to a rapid doubling time, high growth fraction (the ratio of proliferating cells to total cells), and greater propensity for early development of widespread metastases.…”

“…Because 90% to 95% of SCLCs arise from lobar or main bronchi, the most common manifestations of SCLC is a large mass centrally located within the lung parenchyma or a mediastinal mass involving the hilum. [ 9 , 10 ] However, SCLC may occasionally arise as a relatively small bronchial tumor. Contrast-enhanced CT scans can be useful for the diagnosis and revealing the extent of mediastinal invasion.…”

“…However, only a few studies have reported CT findings of SCLC. Lee et al [ 9 ] reported distribution of lymph node enlargement and classified the SCLC types according to tumor location and meditational extension on CT scans and identified recognizable CT features for predicting SCLC. SCLC was classified into 4 types.…”