Background: Dysplastic gangliocytoma (Lhermitte-Duclos disease [LDD]) typically presents as a PTEN (phosphatase and tensin homolog)-positive, insidious unilateral mass of the cerebellar cortex. Patients can present with symptoms of increased intracranial pressure. Magnetic resonance imaging (MRI) will reveal a characteristic laminar/tigroid appearance. Surgical management has been superior to conservative measures for symptomatic lesions. The outcomes for bilateral craniotomy have not yet been described.

Case description: A 50-year-old patient with Cowden syndrome had initially presented with vertigo and imbalance. T2-weighted MRI showed a striated pattern of hypointensity and hyperintensity in bilateral cerebellar hemispheres consistent with Lhermitte-Duclos disease. He underwent right posterior fossa craniotomy with near total surgical resection and achieved symptom resolution. However, 3 years later, asymptomatic recurrence of the right-sided LDD and progression of left-sided LDD were noted. These were managed with a 1-year course of temozolomide. Both lesions remained stable until 4 years after completion of temozolomide. MRI demonstrated progression in the left hemisphere requiring a second surgical resection. PTEN analysis of the resected lesion was negative for mutation.

Conclusions: To the best of our knowledge, the present case is the first reported case of bilateral cerebellar hemisphere LDD ultimately managed by temporally dissociated bilateral surgical resections. Our patient was unique in that he had undergone surgery for resection of LDD, followed by a second surgery for contralateral progression 8 years later. The therapeutic options to prevent recurrence are limited, although temozolomide did seem to impede progression. Symptomatic patients will typically benefit most from surgical intervention. Given the strong association between adult LDD and Cowden syndrome, maintaining close follow-up care and possible surveillance imaging will be essential.