The patient presented in medicine OPD with non-radiating remitting moderate intensity occipital headache for 2 months. There was no history of any trauma or drug intake. The patient was well oriented and could tell the time, place and person. Neurological examination showed no signs of cerebellar dysfunction.
T1WI showed a hypointense lesion in the left cerebellar hemisphere (Fig. 1) which showed alternate iso and hyperintense thickened folia "Tiger striped pattern" on T2WI (Fig. 2, 3a).
The lesion showed mild restriction diffusion on DWI/ADC (Fig 3c, 3d) with no evidence of post contrast enhancement (Fig. 4a), ruling out inflammatory aetiology.
MR spectroscopy showed a mildly reduced choline peak with a reduced Cho/Cr ratio and an almost normal Cho/NAA ratio, ruling out neoplastic aetiology(Fig. 4b).
Lhermitte-Duclos disease (LDD) is a rare hamartomatous lesion of the cerebellar cortex, first described in 1920. It is a rare lesion of the posterior fossa with a reported incidence of about 5 per million per year . It is also known as granular cell hypertrophy, diffuse hypertrophy of the cerebellar cortex, Purkinjeoma, cerebellar hamartoma, gangliomatosis, neurocysticblastoma, ganglioneuroma and hamartomoblastoma . A combination of cerebellar granule neuron aberrant migration & hypertrophy results in its development. It is still not very clear whether this disease process is hamartomatous or neoplastic . Malformative histopathological features such as absent proliferative activity and progression, favour hamartomatous origin. Clinically, patients may remain asymptomatic. However, most times presenting clinical symptoms are due to mass effect resulting in signs of increased intracranial pressure or sometimes mild headache. LDD is commonly associated with other congenital malformations such as multiple hemangiomata, megalencephaly, polydactyly, and skull abnormalities . LDD association with Cowdens disease is well established now. Lhermitte-Duclos disease appears as a hypodense non-enhancing mass in the cerebellar hemisphere with enhancing and thickened folia on CT. Lack of enhancement on the post contrast scans helped rule out metastatic lesions or inflammatory diseases. Magnetic resonance imaging (MRI) remains the modality of choice in LDD. On MR imaging, LDD appears as a non-enhancing cerebellar mass lesion with a typical “Striated or Tiger stripped” folial pattern due to alternate isointense & hyperintense bands on T2WI corresponding to the thickened cerebellar folia [4, 5]. On diffusion weighted imaging, the lesion appears similar to the normal cortex or may show hyperintensity due to the T2 shine through effect. On angiography lesions appear avascular. Despite the benign nature of the lesion, surgical excision is the treatment of choice for large lesions with mass effect on ventricles, although most centres may prefer conservative management in asymptomatic cases. Long-term follow-up is indicated. In our patient, a repeat scan after 6 month showed no significant change in signal intensity and size of the lesion.
A non-enhancing, unilateral cerebellar mass in a middle-aged patient, which is characterized by a ‘tiger-striped’ pattern of hyperintensity on the T2WI and T2 shine through effect probably suggestive of LDD.
Coexistence with the Cowden syndrome should prompt thorough clinical examination and proper investigations to detect or exclude concomitant malignancies.
Differential Diagnosis List