Lhermitte-Duclos disease (dysplastic gangliocytoma): a case report with CT and MRI.

A 31 year old female was admitted with a one month history of left foot drop and diplopia. CT of the posterior fossa revealed gross displacement of the 4th ventricle by a large non-enhancing cerebellar mass but gave no indication of its nature. MRI sequences showed two masses within the left cerebellar hemisphere extending into the vermis and demonstrated a very unusual septation within the lesion. In addition both cerebellar tonsils were displaced below the foramen magnum and there was a syrinx extending from C2 to the conus. At operation a demarcated lesion was excised from the apparently normal surrounding cerebellar tissue and proved histologically to be Lhermitte-Duclos disease. We believe that these are the first diagnostic magnetic resonance images of this condition.