Reactive alveolar epithelium in chondroid hamartoma of the lung.
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.
Uzaslan
Esra
E
General and Experimental Pathology, University of Bochum, Bochum, Germany.
Ebsen
Michael
M
Freudenberg
Nikolaus
N
Nakamura
Shinobu
S
Costabel
Ulrich
U
Guzman
Josune
J
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*
D015415:Biomarkers; D037662:Pulmonary Surfactant-Associated Protein A