Alaa M Afify1, Basim M al-Khafaji. 1. Department of Pathology, University of Michigan Medical School, 1500 East Medical Center Drive, 2G322, Box 0054, Ann Arbor, Michigan 48109, USA.
Abstract
OBJECTIVE: To evaluate the diagnostic utility of the immunohistochemical expression of thyroid transcription factor-1 (TTF-1) in adenocarcinomas from serous fluid specimens. STUDY DESIGN: Archival paraffin-embedded cell blocks of serous fluids from 82 cases, including 34 cases of metastatic lung adenocarcinoma, 12 of metastatic ovarian adenocarcinoma, 12 of metastatic breast adenocarcinoma, 12 of metastatic gastrointestinal adenocarcinoma and 12 of malignant mesothelioma, were immunostained with anti-TTF-1. All the staining was carried out using a Ventana Automated System. Staining was evaluated according to the intensity of the nuclear staining (1+ to 4+) by two observers. RESULTS: Of the metastatic lung adenocarcinomas, 79% (27/34) expressed 3+ to 4+ reactivity against TTF-1. None of the malignant mesotheliomas or other metastatic adenocarcinomas expressed nuclear reactivity. CONCLUSION: Immunostaining with TTF-1 is a useful marker that can be applied to cytologic specimens. Anti-TTF-1 can be used as a reliable component of an antibody panel to support the diagnosis of adenocarcinoma of pulmonary origin in patients presenting with metastatic adenocarcinoma in serous fluid with an unknown primary site.
OBJECTIVE: To evaluate the diagnostic utility of the immunohistochemical expression of thyroid transcription factor-1 (TTF-1) in adenocarcinomas from serous fluid specimens. STUDY DESIGN: Archival paraffin-embedded cell blocks of serous fluids from 82 cases, including 34 cases of metastatic lung adenocarcinoma, 12 of metastatic ovarian adenocarcinoma, 12 of metastatic breast adenocarcinoma, 12 of metastatic gastrointestinal adenocarcinoma and 12 of malignant mesothelioma, were immunostained with anti-TTF-1. All the staining was carried out using a Ventana Automated System. Staining was evaluated according to the intensity of the nuclear staining (1+ to 4+) by two observers. RESULTS: Of the metastatic lung adenocarcinomas, 79% (27/34) expressed 3+ to 4+ reactivity against TTF-1. None of the malignant mesotheliomas or other metastatic adenocarcinomas expressed nuclear reactivity. CONCLUSION: Immunostaining with TTF-1 is a useful marker that can be applied to cytologic specimens. Anti-TTF-1 can be used as a reliable component of an antibody panel to support the diagnosis of adenocarcinoma of pulmonary origin in patients presenting with metastatic adenocarcinoma in serous fluid with an unknown primary site.