title: Small cell lung carcinoma: Eight types of extension and spread on computed tomography.
abstract: OBJECTIVE
  The aim of this study was to classify the types of tumor extension and spread of small cell lung carcinoma (SCLC) and to recognize the unusual types of spread pattern of SCLC on computed tomography (CT) including multidetector row CT (MDCT) using contrast-enhanced material.
  
  
  METHODS
  Sixty-eight cases (53 men and 15 women aged 54-83 years old) of pathologically proven SCLC were examined mainly by contrast-enhanced CT scan. In surgically treated 7 cases, CT-pathologic correlations were performed.
  
  
  RESULTS
  Eight types of extension and spread were recognized by the examinations of chest CT. The type of central mass + mediastinal extension (n = 20 [29.4%]) was the most common manifestation. The types of central perihilar mass (n = 12 [17.6%]), peripheral mass + mediastinal extension (n = 14 [20.6%]), and peripheral mass (n = 7 [10.3%]) were frequently observed. The primary site of SCLC was in peripheral lung tissue in 21 of 68 cases (30.9%) in this study. Unusual CT manifestations, such as the types of lymphangitic spread (n = 6 [8.8%]), pleural dissemination (n = 4 [5.9%]), lobar replacement (n = 3 [4.4%]), pneumonialike air-space infiltrative spread (n = 2 [2.9%]) were recognized in our study. Stenosis of trachea and main bronchus caused by peribronchial extension were commonly noted. In the advanced cases with mediastinal extension, we observed the extension of SCLC to superior vena cava (n = 22), main pulmonary artery (n = 18), pulmonary vein (n = 11), and thoracic aortic wall (n = 7). Peri-and intracardial invasions were also observed in 9 cases.
  
  
  CONCLUSIONS
  Computed tomography including MDCT analysis revealed 8 types of extension and spread of SCLC including unusual forms in 68 SCLC cases. Peribronchial extension and great vessel wall involvement, such as superior vena cava, main pulmonary artery, and peri-/intra-cardial extension, were commonly observed in advanced stage.
authors.affiliation: Department of Radiology, Kyoto University Hospital, Shogoin Kawaharamachi 54 Sakyo, Kyoto-City, Kyoto Prefecture Japan. nk1207@kuhp.kyoto-u.ac.jp
authors.forename: Nobukata
authors.initials: N
authors.lastname: Kazawa
authors.forename: Masanori
authors.initials: M
authors.lastname: Kitaichi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hiraoka
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
authors.forename: Naoshi
authors.initials: N
authors.lastname: Mio
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
authors.forename: Hiromi
authors.initials: H
authors.lastname: Wada
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media