両眼性脈絡膜骨腫の家族例

Familial bilateral occurrence of choroidal osteoma

　両眼性に発症した典型的な脈絡膜骨腫choroidal osteomaを，24歳女子と26歳の姉に観察し，さらにこの姉妹の49歳の父の両眼に，乳頭鼻側から黄斑部下方にかけて，広い帯状の網脈絡膜萎縮に脈絡膜骨腫が混在すると推定される病巣を観察した．また，これら3症例のすべてに，梨子地眼底として形容できる，周辺部眼底にびまん性に網膜背景の黄褐色の不透明化と，不規則な斑状の色素増殖が見られた．

　脈絡膜骨腫がこのような家族内発症をしたことは，本症が常染色体優性遺伝をしていると解釈された．また，梨子地眼底が眼底周辺部に起こることは，脈絡膜骨腫の前段階ないしはその素地となっている変化であり，脈絡膜骨腫の診断ならびに発症機転の解明に重要な意味を持つ所見であると判断された．

Three members of a family manifested typical funduscopic features of choroidal osteoma bilaterally. The affected members included a 24-year-old female, her 26-year-old sister and their father aged 49 years. All the three cases showed normal visual acuity. The osteomas were located in the posterior fundus sparing the macula. Besides the presence of cho-roidal osteoma, which was also confirmed by CT scanning, all the affected 6 eyes manifested mottling of the fundus pigmentation extending over the midperipheral area. This mottling seemed to indi-cate the presence of pathologically affected retinalpigment epithelium as a possible precursor of osteo-ma formation.

The present findings show that choroidal osteoma may occur conforming to an autosomal dominant hereditary pattern. The fundus mottling would merit due attention as a collateral clinical feature of choroidal osteoma.