59-year-old man with history of glioblastoma status post resection with adjuvant chemotherapy and radiation therapy completed 10/20/2016. Postoperative findings are seen at the junction of the left parietal and temporal lobes. The previous hemorrhage-containing surgical cavity has evolved into a larger cystic space with homogeneous T2 hyperintense, T1 hypointense fluid which does not suppress on FLAIR imaging suggesting proteinaceous contents. In largest cross-sectional dimension (6/20), this measures 48 x 31 mm. Surrounding this cystic space is a rim of new, continuous enhancement. While this rim of enhancement is prominently smooth and thin, there is thicker and in some areas nodular enhancement along its superior margin. No additional suspicious foci of enhancement are seen.T2/FLAIR signal hyperintensity in the surrounding white matter extending to the atrium of the left lateral ventricle, and into the splenium of the corpus callosum, has progressed. Scattered small foci of signal hyperintensity in the right superior frontal gyrus and the right inferior frontal gyrus are unchanged and nonspecific. Very small foci of diffusion restriction surrounding the surgical cavity have decreased from the prior exam. Slight susceptibility artifact surrounding the surgical cavity is suggestive of trace residual blood products, but there is no significant intracranial hemorrhage. Mass effect upon the left lateral ventricular atrium has slightly increased. Otherwise, the ventricles are normal in size and morphology.
A fluid-filled, rim-enhancing lesion has developed at the junction of the left parietal and temporal lobes, at the site of the prior resection cavity. The enhancing rim of this lesion is predominantly thin and smooth, though there is thick and nodular enhancement along its superior margin. Given the recent timing of treatment, these findings could at least in part represent treatment effect, but there is suspicion for viable tumor as well.