T1 coronal post gad T1 axial post gad T2 axial

Diagnosis: Grade 3 oligodendroglioma- recurrent.

Oligodendrogliomas represent about 10% of all glial neoplasms and are often indolent lesions involving the cortex. They are extremely rare in children and usually present in young adulthood with seizures. Calcification and cystic change are common and enhancement is variable. They usually involve the frontal lobe and are very rare in the posterior fossa. This appearance may be compatible with a low grade astrocytoma; however, the mostly cortical location of the signal abnormality is unusual for astrocytoma. This site is more typical of a ganglioglioma however they tend to be cystic and well circumscribed with a nodular enhancing component. This patient was biopsied in 1972 and radiated. An indolent lesion present for over 20 years plus the cortical location suggests oligodendroglioma rather than low grade astrocytoma. The increased T2 signal in the periventricular occipital white matter is probably due to prior radiation with a higher dose given from the left. Related Cases

Oligodendroglioma Ganglioglioma Multiple Astrocytomas