title: Expression of thyroid transcription factor-1 in malignant pleural effusions.
abstract: Separating adenocarcinoma of the lung from non-pulmonary adenocarcinoma or malignant mesothelioma is difficult, especially in cytology specimens. Consequently, it is important to identify markers that may facilitate this distinction. Thyroid transcription factor-1 (TTF-1) is a homeodomain containing transcription factor expressed selectively in the thyroid, lung, and diencephalon. TTF-1 is also expressed in adenocarcinomas of the lung and is widely used as a pulmonary adenocarcinoma marker in surgical specimens. However, the utility of TTF-1 has rarely been investigated in cytology. In this study, we evaluated the expression of TTF-1 in malignant pleural effusions. The primary tumors included 26 pulmonary adenocarcinomas, 26 non-pulmonary adenocarcinomas (13 breast, 5 ovarian, 2 gastric, 2 prostatic, 1 esophageal, 1 colonic, 1 pancreatic and 1 renal) and 4 malignant mesotheliomas. Immunocytochemistry was performed on sections of cell blocks, using a mouse monoclonal TTF-1 antibody (clone 8G7G3/1) and a biotin-streptavidin detection system. Nuclear immunoreactivity for TTF-1 was detected in 19 pulmonary adenocarcinomas. All non-pulmonary adenocarcinomas and malignant mesotheliomas were negative. These data indicate that TTF-1 maintains its sensitivity (73%) and specificity (100%) in cell block preparations and is useful in separating adenocarcinoma of the lung from non-pulmonary adenocarcinoma and malignant mesothelioma in cytology specimens.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA. khoor.andras@mayo.edu
authors.forename: Andras
authors.initials: A
authors.lastname: Khoor
authors.forename: Angela L
authors.initials: AL
authors.lastname: Byrd-Gloster
authors.forename: Santo V
authors.initials: SV
authors.lastname: Nicosia
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000175:diagnosis*; D008297:Male; D008654:Mesothelioma / Q000175:diagnosis; D009687:Nuclear Proteins / Q000096:biosynthesis*; D016066:Pleural Effusion, Malignant / Q000209:etiology / Q000378:metabolism*; D012680:Sensitivity and Specificity; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000096:biosynthesis*
chemical_list: D014408:Biomarkers, Tumor; C000614412:NKX2-1 protein, human; C000614414:Nkx2-1 protein, mouse; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors