Presentation
Headaches.
Patient Data
A non-enhancing region within the vermis and left cerebellar hemisphere is seen, with mass effect and hydrocephalus.
Intraaxial mass-like lesion is demonstrated in the left cerebellar hemisphere and vermis. It is heterogeneously high-signal on T2-weighted imaging, with a striated appearance. There are multiple flow voids related to the lesion, although most appear to be at the peripheries and may be adjacent or in compressed sulci. On postcontrast T1-weighted imaging, there is only enhancement of vessels with no convincing enhancement of the lesion. No associated cystic component. MRS is unremarkable (not shown).
The mass distorts the fourth ventricle, compressing the foramina of Magendie and Luschka with resultant hydrocephalus. The mass also expands the left cerebellar hemisphere, with descent of the left cerebellar tonsil 10 mm below the foramen magnum.
No other intracranial lesion. No collection or acute hemorrhage. No cortical infarct.
Conclusion: Features are those of a dysplastic cerebellar gangliocytoma (Lhermitte-Duclos disease).
Case Discussion
The patient went on to have a biopsy.
Histology
Sections of cerebellum show enlarged, architecturally distorted folia. There is diffuse enlargement of the molecular and internal granular layers expanded by a population of ganglion cells. The outer molecular layer contains abnormal bundles of myelinated axons. There are focal deposits of dystrophic calcification present. The dysmorphic ganglion cells contain abundant amphophilic cytoplasm, oval vesicular nuclei and prominent nucleoli. No necrosis or microvascular proliferation is seen. There is no evidence of malignancy.
FINAL DIAGNOSIS: dysplastic cerebellar gangliocytoma (Lhermitte Duclos disease) - WHO Grade I.