Thyroid transcription factor-1 staining is useful in identifying brain metastases of pulmonary origin.
Metastatic carcinomas of the brain are a common intracranial tumor and may be the first manifestation of the cancer in a patient. The primary site of these tumors is often difficult to determine based solely on histology. Thyroid transcription factor-1 (TTF-1) is a fairly specific immunohistochemical marker for primary lung and thyroid carcinomas. Recent studies have indicated that TTF-1 may be useful in identifying metastatic brain carcinomas arising from primary lung carcinomas. This study evaluates TTF-1 immunoreactivity in 101 metastatic brain carcinomas and 50 glioblastoma multiform. In patients with a known pulmonary primary, 59% of the metastases were positive for TTF-1. The one patient with a thyroid primary also had a metastasis positive for TTF-1. None of the metastatic lesions arising from other sites was positive for TTF-1. None of the 50 glioblastoma multiform was positive for TTF-1. This study indicates that TTF-1 may be useful in evaluating metastatic carcinomas of unknown primary and TTF-1 immunoreactivity may be indicative of a lung or thyroid primary.
Prok
Alan L
AL
Department of Anatomic Pathology, The Cleveland Clinic Foundation, Cleveland OH 44195, USA.
Prayson
Richard A
RA
D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D002277:Carcinoma / Q000175:diagnosis* / Q000556:secondary; D005909:Glioblastoma / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000473:pathology*; D009687:Nuclear Proteins / Q000032:analysis*; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000032:analysis*
C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors