[A Case of Cowden Syndrome Associated with Lhermitte-Duclos Disease].

A 24-year-old woman slowly developed mild unsteadiness of gait. Neurological examination revealed mild dysmetria of the left upper and lower limbs. Standing and gait were unsteady, and tandem gait was impossible. Cranial magnetic resonance imaging (MRI) showed an enlarged left cerebellar hemisphere with striated lines, a characteristic finding of Lhermitte-Duclos disease. She also had papules on the forehead, goiter, lactating adenoma, glycogenic acanthosis in the esophagus, café-au-lait spot, and hemangioma and keratosis on the dorsum of foot. The diagnosis of Cowden syndrome was established by finding the mutation in the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene. Cowden syndrome is an autosomal dominant disorder characterized by multiple hamartomas in a variety of tissues. Recognition of Lhermitte-Duclos disease as a neurological condition of Cowden syndrome is important, and once the diagnosis of Lhermitte-Duclos disease is made, a close physical investigation is necessary because the hamartomas tend to develop malignancies. (Received March 15, 2017; Accepted July 24, 2017; Published December 1, 2017).