title: Reactive alveolar epithelium in chondroid hamartoma of the lung.
abstract: OBJECTIVE
  To determine the morphologic characteristics of the nonciliated epithelium found in chondroid hamartoma of the lung.
  
  
  METHODS
  The morphologic characteristics and immunohistochemical reaction for surfactant protein A of the nonciliated epithelium in chondroid hamartoma of the lung was studied by immunohistochemistry. Alveolar epithelium in normal lung tissue and lung tissue surrounding primary lung cancer or metastatic lung lesions was used as a control.
  
  
  RESULTS
  In all cases, the nonciliated epithelium in chondroid hamartoma showed the morphologic criteria of hyperplastic alveolar type II cells and a very strong positive surfactant protein A reaction in the cytoplasm when compared with alveolar epithelium of the normal lung. Similar hyperplastic type II cells were also found in the alveolar lung around metastatic or primary lung tumors.
  
  
  CONCLUSIONS
  These findings may indicate that the nonciliated cells found in chondroid hamartoma of the lung are hyperplastic type II cells. This suggests that the alveolar epithelium found in chondroid hamartoma of the lung is a secondary reaction around the hamartoma and not a primary component of the lesion.
authors.affiliation: General and Experimental Pathology, University of Bochum, Bochum, Germany.
authors.forename: Esra
authors.initials: E
authors.lastname: Uzaslan
authors.forename: Michael
authors.initials: M
authors.lastname: Ebsen
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Freudenberg
authors.forename: Shinobu
authors.initials: S
authors.lastname: Nakamura
authors.forename: Ulrich
authors.initials: U
authors.lastname: Costabel
authors.forename: Josune
authors.initials: J
authors.lastname: Guzman
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D015415:Biomarkers; D002356:Cartilage / Q000473:pathology*; D002828:Choristoma / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006222:Hamartoma / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008171:Lung Diseases / Q000473:pathology*; D008175:Lung Neoplasms / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011650:Pulmonary Alveoli / Q000473:pathology*; D037662:Pulmonary Surfactant-Associated Protein A / Q000378:metabolism; D020545:Respiratory Mucosa / Q000473:pathology*
chemical_list: D015415:Biomarkers; D037662:Pulmonary Surfactant-Associated Protein A