METASTATIC ADENOCARCINOMA TO THE BRAIN - MR WITH PATHOLOGICAL CORRELATION

PURPOSE: To describe the appearance on T2-weighted scans of metastatic adenocarcinoma to the brain and to show that the hypointensity freque ntly associated with these lesions is not related to the presence of m ucin, blood products, iron, or calcium. METHODS: The MR scans of 14 pa tients with metastatic adenocarcinoma to the brain were reviewed retro spectively. The signal intensity on T2-weighted scans of the solid enh ancing portion of the tumors was compared with white matter. Histologi c examination of the surgical specimens included special stains to sea rch for calcium, mucin, and iron. RESULTS: Eight of nine surgical and all six nonsurgical lesions were either iso- or hypointense to white m atter on T2-weighted scans. There was no correlation with tumor histol ogy or the presence of mucin, blood products, iron, or calcium. CONCLU SIONS: The presence of a hypointense intraaxial mass on T2-weighted sc ans strongly suggests the possibility of metastatic adenocarcinoma. Th e MR appearance is not explained by the presence of mucin, blood produ cts, iron, or calcium. This phenomenon most likely reflects the relaxa tion parameters of the tissue from which the metastasis arose.