Clinical question: assess brain massSigns and Symptoms: posterior fossa mass on CT, HA There is a 33 x 38 mm sagittal dimension heterogeneously enhancing mass centered in the vermis which measures 33 mm in width. There are punctate foci of susceptibility effect associated with this. On T2 imaging there are cystic-appearing components as well as low signal component medially. It appears multiseptated and well circumscribed. There is no associated diffusion restriction. There is surrounding T2 and FLAIR signal hyperintensity within the left cerebellar hemisphere into a lesser degree right cerebellar hemisphere compatible with edema and/or tumor infiltration. There is some signal hyperintensity present within the medial aspect of the left middle cerebellar peduncle on T2 and FLAIR imaging. It is associated with the mass effect and compression of the fourth ventricle. The lateral ventricles are minimally dilated. The cerebellar tonsils are low lying.There is a mild degree of periventricular and subcortical punctate hyperintense white matter lesions present identified in the frontal lobes and parietal lobes bilaterally on the FLAIR and T2 images.Normal vascular flow voids are present in the distal carotid and vertebral arteries, the basilar artery and the proximal anterior, middle and posterior cerebral arteries as well as the internal cerebral veins and superior sagittal sinus.The visualized portions of the paranasal sinuses are clear. The visualized portions of the mastoid air cells are clear. The visualized portions of the orbits are intact. There is thinning of the left posterior sclera compatible with staphyloma. The right eye is irregular in shape. There is no enhancing lesion identified in the right eye.Fiducial markers are in place.
1.There is a well circumscribed multiseptated mass centered in the superior aspect of the vermis and eccentric towards the left which is suspicious for neoplasm. This mass compresses the fourth ventricle but is currently not associated with any significant amount of ventriculomegaly. In this age group metastatic disease is the most likely explanation. The patient is known to have a history of colon cancer. A primary brain tumor would be alternative but less likely.2.There is a staphyloma in the left eye. 3.The right eye is irregular and the right retina possibly appears thickened. This is an equivocal finding. The possibility of retinal lesion cannot be excluded if clinically appropriate ophthalmoscopy the may be of further benefit