Membranous Lipodystrophy （Nasu）の1剖検例

AN AUTOPSY CASE OF MEMBRANOUS LIPODYSTROPHY (NASU)

　抄録　35歳で骨症状，その約10年後に神経精神症状を生じ，50歳で死亡したmembranous lipodys—trophy （Nasu）の男性剖検例を報告した。本邦では9例目に該当し，最年長例であった。両親はいとこ結婚で，次姉は35歳膀胱癌で死亡したが，骨粗鬆症と病的骨折を多発し，脂肪織に膜嚢胞変性を認め，同胞発生例と考えた。X線上，四肢長管骨の主に骨端部に多発性嚢胞状透亮像を認めた。3年間のCTによる観察では，神経症状の著しい増悪に比べると脳萎縮の進行は軽度であり，基底核の石灰化，大脳白質内の低吸収域は認めなかった。剖検により，背椎骨の他，全身脂肪織に特徴的な膜嚢胞性病変を認めた。神経病理学的には脳重最1,030g，前頭葉優位の脳回萎縮，白質のびまん性萎縮を認めた。前頭葉に限局した脱髄巣とその一部の血管周囲に軽微なズダン好性脂肪顆粒の出現を認めたが，線維性gliosisはびまん性にみられ，硬化性白質脳症を示した。大脳自質，特に外包付近に多数のspheroidを認め，その電顕像ではneurofilamentの著しい増生，多数のvesicleと共に，小塊状の高電子密度の物質が胞体内に一様に点在し，mitochondriaの多くは変性していた。これらの所見から軸索の一次的変性過程の存在が示唆された。

Membranous lipodytrophy (Nasu) is characteri-zed by polycystic osteodysplasia associated with dementia. We recently experienced a 9th autopsy case in Japan. This 50 year-old male, eldest in the reported autopsied case in Japan, presented bone fracture at 35 year of age and dementia started at 45. His parents were cousins. His sister, died with carcinoma of the bladder at 35, develo-ped marked osteoporosis with multiple pathologi-cal fractures and "membrano-cystic" lesions were found in her adipose tissue. The roentgenogram of the patient's long bone revealed radiolucent and cystic areas with irregular boundaries at the metaphyses. Computer tomography of the brain examined during the last 3 years showed slowly progressive brain atrophy. Calcifications of the basal ganglia or low density area in the white matter were not foud.

Autopsy showed typical "membrano-cystic" le-sions in the adipose tissue of the whole body including bone marrow.

Brain weighed 1,030 g. There was a mild con-volutional atrophy at the frontal lobe. White mat-ter was diffusely atrophic. Demyelination was li mited to the frontal lobe, where only small num-ber of perivascular sudanophilic lipid-laden mac-rophages were found. Fibrillary astrocytes were rather diffusely proliferated, consistent with scle-rosing leukoencephalopathy. Many spheroids were found in the frontal and occipital deep white matters, and external capsule. Ultrastructural study of spheroid revealed increased amount of neuro-filament, vesicles with free patchy dense materials and degenerated mitochondria, which were consis-tent with primary axonal degeneration.