Sunday 29 December 2013

Lhermitte Duclos disease MRI

MRI Brain T2w images show a well demarcated hyper intense lesion in right cerebellum with striations ("corduroy" sign). Despite of its size results in little mass effect.

Lhermitte-Duclos disease (Dysplastic cerebellar gangliocytoma)

• Cowden syndrome (CS) ~ multiple hamartoma syndrome, multiple hamartoma-neoplasia syndrome.
o Hamartoma of cerebellum.
o Hamartoblastoma.
o Granule cell hypertrophy, granulomolecular hypertrophy.
o Diffuse ganglioneuroma of cerebellar cortex.
o Neurocytic blastoma.
o Myelinated neurocytoma.
o Purkingeoma.

Dysplastic cerebellar gangliocytoma (LD) is a rare tumour of cerebellum.
Grading WHO grade 1 tumor.
Varies in size and extent, always occur in cerebellum.

Imaging findings: 
Generally affects one hemisphere but commonly extends to vermis, as a well demarcated area of abnormal low density on CT / T2 hyper intensity on MRI with striations ("corduroy" or "tiger-striped" pattern).
No edema.
Usually little mass effect.
No restricted diffusion on MRI Diffusion.
No enhancement on post contrast. Very rarely mild enhancement.
MRS Reduced NAA, decreased to normal Choline, raised Lactate.

Histopathological findings: 
Gross pathologic and surgical features includes markedly enlarged cerebellar hemisphere/vermis with thick folia, Pale appearing mass.
Microscopic features includes widening of molecular cell layer ~ occupied by abnormal ganglion cells, Absence of Purkinje cell layer, Hypertrophy of granule cell layer, decreased volume of white matter.
Histologically may be confused with ganglion cell tumor

Clinical Presentation: 

Signs/symptom are often vague related to raised intracranial pressure, brainstem and cerebellar findings (cranial nerve palsies, ataxia), hydrocephalus.
Onset of symptoms most common during 3rd-4th decades of life
Age and Gender:
Any age, birth-60 years, more common between 30-40 years.
M = F / M >  F

LD is very rare, all patients must be screened for CS.
Cowden syndrome is a hereditary hamartoma-tumor syndrome ("phakomatosis") characterized by
1. LD in brain,
2. Mucocutaneous lesions,
3. Multiple hamartomas/neoplasias in breast/thyroid,
4. Gastrointestinal tract polyps,
5. Genitourinary malignancies,

Clinically CS include:
Benign breast, skin lesions
Oral papillomas,
Benign thyroid lesions (adenomas),
Gastrointestinal tract polyps/hamartomas,
Genitourinary neoplasias.

Surgical resection in symptomatic patients
Borders of lesion blend into normal surrounding cerebellum may cause total resection difficult.

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