The Center for Cerebellar Malformations
Lhermitte-Duclos Disease
(PTEN mutations)
General Information
This is
a rare dysplastic hamartomatous gangliocytoma of the cerebellar midline. It is
believed to be a result of overgrowth of hypertrophic ganglion cells that
replace the granular-cell layer and Purkinje cells of the cerebellum, resulting
in global thickening of the cerebellar folia (Albrecht et al., 1992; Ambler et al., 1969; Nowak and
Trost, 2002). Clinically, patients
with LDD may present with ataxia, signs and symptoms of increased intracranial
pressure, and seizures. Surgery
may be required to relieve posterior fossa pressure or hydrocephalus (Tuli et al., 1997). It is
also critical to distinguish LDD from medulloblastoma, as they may appear
similar on brain imaging studies (Chen et al., 2002).
In
approximately half of the published cases of LDD, there are features of Cowden
syndrome (Robinson and Cohen, 2000), an autosomal-dominant condition with age-related
penetrance characterized by multiple hamartomas affecting derivatives of all
three germ layers and by a high risk of breast, thyroid, and endometrial
cancers (Eng, 2000; Marsh et al., 1997; Robinson and Cohen,
2000). Germline mutations in
the PTEN (Phosphatase and Tensin
homologue) gene are a frequent cause of Cowden syndrome, and mutations in this
gene have been identified in some patients with LDD (Liaw et al., 1997; Nelen et al., 1997), but the frequency of these mutations among these
patients is unknown. Careful diagnosis is important, because recognition may
lead to earlier diagnosis of systemic malignancies (Prabhu et al., 2004).
MRI Scans
T1 weighted images.
LEFT: Coronal view showing thickened cerebellar folia (multiple linear
striations). RIGHT: Sagittal view showing
multiple enlarged folia and vermis, reduced fourth ventricle. (modified from
Bero et al 2000)