title: Clear cell tumor of the lung: Two case reports and a review of the literature.
abstract: BACKGROUND
  Clear cell tumor of the lung (CCTL) is a rare and mostly benign pulmonary tumor arising from perivascular epithelioid cells. We reported 2 cases of CCTL in a 24-year-old man with chest pain and a 59-year-old man with dyspnea.
  
  
  METHODS
  Their chest CT images revealed a well-defined, homogeneous nodule located in the peripheral region of lung parenchyma. The solid nodule showed intense heterogenous postcontrast enhancement in the arterial phase and a homogenous appearance in the venous phase. The two patients underwent thoracotomy, and pathological examinations, including immunohistochemical studies revealed that both cases were benign clear cell tumors.
  
  
  RESULTS
  Due to the fact that only a few cases about CCTL were reported, clinicopathological aspects and radiological characteristics of this type of tumor are not well established.
  
  
  CONCLUSIONS
  CCTL is a rare and benign primary tumor and majorly occurs in middle-aged and elder people. The finding of a small vessel extending along and partially wrapping up one side of the mass in the CT-enhanced images might be a helpful feature to differentiate CCTL from other lung neoplasms.
authors.affiliation: Department of Radiology Department of Pathology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu Province, P.R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.forename: Cailuan
authors.initials: C
authors.lastname: Lu
authors.forename: Linlin
authors.initials: L
authors.lastname: Li
authors.forename: Kai
authors.initials: K
authors.lastname: Xu
mesh_terms: D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D054973:Perivascular Epithelioid Cell Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed; D055815:Young Adult