Reason: grade III oligodendroglioma, s/p RT/TMZ, 12 cycle TMZ, assess status History: grade III oligodendroglioma, s/p RT/TMZ, 12 cycle TMZ, assess status. There is redemonstration of the expansile infiltrative T2/FLAIR hyperintense lesion extending along the left pons, midbrain, and into the left thalamus. There is again no associated enhancement or diffusion restriction. There is a similar degree of lobulated extension into the mesial left temporal lobe, with localized mass effect. Compared to more recent exams, this area of abnormality is unchanged, although comparing to more remote exams suggests gradual decreased size since September 2013. However, there is now increased conspicuity of small cysts along the medial aspect of the lesion seen on 8/20-21. There is increased conspicuity of the anterior oval cyst, with emergence of a now well delineated 7 mm posterior cyst on 6/15. On perfusion imaging, there is relative hypoperfusion along the area of abnormal signal in the left brainstem and thalamus.There is redemonstration of subtle FLAIR hyperintensity along the left ventral lateral cerebellum, and questioned along the right ventral pons on T2-weighted images. The right ventral medulla also appear slightly asymmetrically prominent on 6/5 with questioned abnormal signal.Postsurgical changes including right cerebellar tissue loss appear similar to the prior exam. There has been slight interval increased number of scattered foci of susceptibility, especially along the superior frontal gyri, which may be posttreatment related. There is no pathological enhancement.The ventricles and basal cisterns prominent for age, consistent with diffuse volume loss. There is no midline shift or herniation. The major cerebral flow voids are intact.
1. No significant recent change in size of the left brainstem/thalamic nonenhancing infiltrative mass, although overall gradually decreasing in size since baseline exam. Increased conspicuity and size of discrete cysts along the medial aspect of the lesion. Overall, is no definite associated hyperperfusion.2. Stable additional questioned areas of subtle signal and contour abnormality along the left ventral cerebellum, right ventral pons and possibly the right ventral medulla. Continued follow-up is recommended.