ABSTRACT
Pulmonary blastomas (PBs) are rare primary malignancies that include adult types: biphasic pulmonary blastoma (BPB) and well-differentiated fetal adenocarcinoma (WDFA); and childhood type: pleuropulmonary blastoma (PPB). Their pathogenesis and relationship to bronchogenic carcinoma (BCA) are controversial. To determine whether or not PB share molecular pathological features with BCA, the authors immunostained three BPB, three WDFA, three PPB, and 80 standard BCA for p53 protein and MDM2 protein, gene products believed to be significant in the pathogenesis of BCA. Paraffin-embedded tissue sections were immunostained with monoclonal antibody to p53 and MDM2 proteins. Strong intranuclear staining in greater than 10% of cells was considered positive. Three (50%) BPB and WDFA stained for p53 and five (83%) for MDM2. None of the PPB stained for p53, and one PPB did not stain for either p53 or MDM2. Five of six adult type PB occurred in smokers, whereas none of the PPB was associated with smoking. Seventy-five (94%) of the BCA stained for MDM2 and 46 (61%) for p53. Immunostaining patterns for p53 and MDM2 in adult types of PB, and not PPB, appear similar to those for BCA. This may suggest that adult type PB, but not childhood PB, have a similar pathogenesis to BCA.
Subject(s)
Carcinoma, Bronchogenic/chemistry , Lung Neoplasms/chemistry , Neoplasm Proteins/analysis , Nuclear Proteins , Proto-Oncogene Proteins/analysis , Pulmonary Blastoma/chemistry , Tumor Suppressor Protein p53/analysis , Adenocarcinoma/chemistry , Adenocarcinoma/pathology , Adult , Aged , Biomarkers, Tumor/analysis , Carcinoma, Bronchogenic/pathology , Child, Preschool , Female , Fetus , Humans , Immunohistochemistry , Infant , Lung Neoplasms/pathology , Male , Middle Aged , Proto-Oncogene Proteins c-mdm2 , Pulmonary Blastoma/pathology , Staining and LabelingABSTRACT
We report two cases of peripheral biphasic adenocarcinoma primary in the lung. To our knowledge, peripheral adenocarcinoma of the lung with a spindle-cell component has not been described previously. Diffuse positive cytokeratin and negative vimentin immunostaining of the spindle-cell components support an epithelial differentiation of the malignant spindle cells. Although study of additional cases is needed, our initial findings suggest that immunohistochemical staining pattern may help distinguish these neoplasms from other biphasic neoplasms primary or secondary to the lung, such as carcinosarcoma or malignant mesothelioma.
