Further evaluation of cerebellar lesion. History of medulloblastoma. Status post resection in April 2007 followed by chemotherapy and radiation treatment (which was reported). Presented with three-week history of worsening headache, nausea and vomiting. CT scan of the head from outside institution shows right cerebellar mass. BRAIN: A lobulated, septated mass has developed in the lateral aspect of the right cerebellar hemisphere, at the site of previous tumor resection. The mass measures axially 3.9 cm x 3.6 cm and craniocaudally 2.4 cm. The mass is partly solid and partly cystic, with the largest cystic component being in the superior medial aspect of the mass along its interface with the cerebellar parenchyma, measuring up to 2.4 cm. The solid component shows heterogeneous contrast enhancement and diffusion restriction, reflecting dense hypercellularity. There is vasogenic edema in the right cerebellar hemisphere extending along the right-sided cerebellar peduncles. In addition to deforming the right cerebellar hemisphere and causing downward herniation of the right cerebellar tonsil 8 mm below the level of the foramen magnum, the mass also deforms the brainstem and partially effaces the fourth ventricle and its outflow tracts without obstructive hydrocephalus. The mass, along its superior part, abuts the junction between the right transverse and sigmoid sinuses without definite invasion. There is mild dural thickening and enhancement subjacent to the right retrosigmoid craniotomy but this is nonspecific and can be postoperative.There is no other contrast-enhancing or space-occupying brain lesion. There is no acute infarct. There is no sizable intracranial hemorrhage. A few, tiny foci of susceptibility effect in the occipital and frontal lobes may reflect mineralizing angiography from previous radiation treatment. Supratentorially, the ventricles and other CSF-containing spaces are normal in size and there is no midline shift. The major intracranial vascular flow voids are preserved.There is mild mucosal thickening in the left sphenoid and right maxillary sinuses. There are small cystic lesions involving the left ear pinna without associated inflammatory change, which were not present on the previous examination. Please correlate with possible history of ear piercing and physical examination.WHOLE SPINE:Cervical: There is reversal of the normal cervical lordosis along with desiccation of the upper and mid cervical discs. There is also a mild leftward convex curvature. There is no significant spinal canal or neural foraminal stenosis. The cervical spinal cord is unremarkable. There is no abnormal intrathecal contrast enhancement. Thoracic: Alignment is anatomic. The vertebral bodies and discs are preserved in height. The spinal canal is preserved. The thoracic spinal cord is unremarkable. There is no abnormal intrathecal contrast enhancement.Lumbar: Off note, there are 6 lumbar-type vertebrae and the last well-formed disc is at S1-S2. Alignment is anatomic accounting for straightening which may relate to patient position. The vertebral bodies and discs are preserved in height. The spinal canal is preserved. The conus medullaris tip lies at L1-L2 level. The conus medullaris is unremarkable. There is no abnormal intrathecal contrast enhancement.
1.Large heterogenous lateral right cerebellar mass along the previous resection cavity margin, most likely represents medulloblastoma recurrence. This shows strong resemblance in composition and signal characteristics to the original tumor from the pretreatment examination from April 3, 2007.2.The associated mass-effect compresses the fourth ventricle and causes secondary Chiari malformation but there is no obstructive hydrocephalus. 3.There is no intracranial metastasis, otherwise. A few, tiny foci of susceptibility effect in the cerebrum may reflect mineralizing angiopathy from previous radiation treatment.4.No spinal drop metastasis. Please note transitional spinal anatomy as above, and if surgery is to be contemplated, correlation with imaging of the entire spine is recommended.