Lhermitte-Duclos病（小脳異形成性神経節細胞腫）を伴ったCowden症候群の1例

A Case of Cowden Syndrome Associated with Lhermitte-Duclos Disease

症例は24歳女性。最近発症した歩行障害を主訴に受診した。神経学的には左上下肢および体幹に軽度の小脳失調を示し，頭部MRIで左小脳半球に縞状模様を呈する腫瘤性腫大を認めたことからLhermitte-Duclos病と診断された。そのほか，前額部丘疹，甲状腺腫，食道グリコーゲンアカントーシス，足背部角化症などを認め，PTEN遺伝子変異が陽性を示したためCowden症候群と診断した。Cowden症候群は全身に過誤腫を生じる常染色体優性の遺伝性疾患である。Lhermitte-Duclos病はCowden症候群の中枢神経病変であり，それを認めた場合には全身の過誤腫を検索し，その悪性化に注意すべきである。

Abstract

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)