Three adolescents with Lhermitte-Duclos disease.

Lhermitte-Duclos disease (LDD) is a rare, benign cerebellar disorder, characterized by replacement of granular cells and Purkinje cells by an overgrowth of cerebellar ganglion cells. LDD can be associated with Cowden's syndrome (CS). We studied three adolescent LDD patients, including two with CS. MRI revealed the typical tiger-stripe pattern in all patients. CS was diagnosed on the basis of secondary mucocutaneous lesions and a PTEN/MMAC1 gene mutation. Adolescent-onset LDD appears to have the same phenotype and genotype as adult-onset LDD. Total resection of the lesion is recommended as an initial management strategy. We strongly recommend that patients with LDD undergo genetic screening to find out as early as possible whether CS has developed.