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.

Interobserver variability in determining MIB-1 labeling indices in oligodendrogliomas.

Several studies have shown that MIB-1 labeling indices correlate well with tumor grade and prognosis in a variety of tumor types. Several factors are responsible for some degree of variability in the determination of labeling indices. Interobserver variability is one of the factors often cited as responsible for this variability.