Male, 51 years old, with history of GBM status post RT, now on temozolomide. Postoperative findings are seen compatible with partial resection of an ill-defined infiltrative and originally minimally enhancing lesion from the left temporal lobe. The lesion originally involved both the lateral and medial aspects of the temporal lobe extending anteriorly along both sides of the temporal horn.Over the subsequent examinations, enhancement has developed around the resection cavity and this has continued to progress on the present study. Enhancement is now seen extending anteriorly along the temporal horn. A significant portion of this enhancing tissue is seen to correlate with elevate rCBV. T2 hyperintensity within and surrounding the lesion has also progressed, now filling the entire left temporal lobe with extension into the occipital lobe and superiorly into the parietal lobe. Regional mass effect is seen in the form of sulcal effacement and effacement of the left ventricular atrium. The left temporal horn is relatively more dilated than on earlier exams, but it is difficult to tell if this is from volume loss or from entrapment and dilatation.Scattered small foci of T2 hyperintensity elsewhere in the cerebral hemispheres are nonspecific and not significantly changed. No definite evidence of tumor involvement is seen in the contralateral hemisphere.Findings related to functional endoscopic sinus surgery are noted on the left. The paranasal sinus mucosa is diffusely thickened.
Progressive irregular enhancement is noted around the left temporal lobe resection cavity extending further anteriorly along the left temporal horn. A significant portion of this enhancing tissue correlates with elevated blood volume which would favor the presence of viable tumor. Given the timing relative to treatment, the possibility of a mixed process with some true progression and some pseudoprogression should also be considered.