Diagnosis: Lhermitte-Duclos disease
Lhermitte-Duclos disease is caused by abnormal ganglion cells in the cerebellar granular layer with thickened and hypermyelinated molecular layer with loss of Purkinje cells. It was first described in 1920, and is also known as granular cell hypertrophy, dysplastic gangliocytoma of the cerebellum, benign hypertrophy of the cerebellar cortex, Purkinjeoma, gangliomatosis of the cerebellum, hamartoma of the cerebellum, myelinated neurocytoma, and gangliocytoma myelinicum diffusum. Associations of LDD include Cowden's disease (most consistent), neurofibromatosis I, megaencephaly, heterotopias, microgyria, hydromyelia, polydactyly, spongioblastomas, hemangiomas, partial giantism, macroglossia, and leontiasis ossea. LDD usually presents with symptoms of hydrocephalus from mass affect upon the fourth ventricle or cerebellar signs including gait disturbance. The average age of presentation is about 35 years, however LDD has been reported in a newborn and has a higher incidence in women. One familial case was reported between a mother and son. On CT, LDD presents as a cerebellar mass which may have calcifications. On MR, signal is usually hypointense to brain on T1 and increased on T2. Gadolinium enhancement, if any, is patchy, probably owing to the abnormal draining veins which may be within or adjacent to the lesion and have been described as a sign of LDD. If the imaging is high enough resolution, the thickening of the dysplastic cerebellar folia may be seen and is considered nearly pathognomonic. Thinning of the adjacent occipital bone may be present and hydrocephalus is a complication. The classic appearance of LDD limits the differential to include atypical astrocytoma as well. In general, the lesion is considered to be a low grade neoplasm with a tendency to grow, become symptomatic, and recur after resection. Treatment consists of resection of as much abnormal tissue as possible. There is no role for chemotherapy or radiation. Follow-up with MR is indicated due to the tendency of LDD to recur. Related Cases Ashley DG, Chi Sing Z, Parakrama T, et al. Lhermitte-Duclos Disease: CT and MRI findings. JCAT, Nov-Dec 1990; 14(6):984-987.
Smith RR, Grassman R, Goldberg H, et al. MR Imaging of Lhermitte-Duclos Disease: A Case Report. AJNR, Jan-Feb 1990; 10:187-189.
Williams DW, Elster AD, Ginsberg LF, et al. Recurrent Lhermitte-Duclos Disease: Report of Two Cases and Association with Cowden's Disease. AJNR, Jan-Feb 1992; 13:287-290.
