Clara cell and type II pneumocyte adenoma. An immunocytochemical and ultrastructural study of three cases
Franco, V.; Aragona, F.; Genova, G.
Pathologica 78(1057): 593-602
1986
ISSN/ISBN: 0031-2983 PMID: 3627846 Document Number: 279317
A combined histological, immunocytochemical and ultrastructural study was performed on three cases of pulmonary adenoma. The histological picture showed clusters, cords or, less frequently, tubules of polygonal cells characterized by indistinct margins, abundant and eosinophilic cytoplasm, oval vesicular nucleus with evident nucleolus. The ultrastructural features of the neoplastic elements were indicative of Clara cells and of type Ii pneumocytes. Cells with intermediate characteristics were frequently observed. Immunoperoxidase staining revealed no positivity for factor VIII-related antigen, keratin and S-100 protein; CEA-positive cells were found only among the cuboidal elements lining the tubular spaces. All cases followed a benign course. In conclusion, the reported tumors are benign epithelial neoplasms, composed by type II pneumocytes and Clara cells.