[An autopsy case of membranous lipodystrophy (Nasu)]

Membranous lipodystrophy (Nasu) is characterized 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, developed marked osteoporosis with multiple pathological 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 found. Autopsy showed typical "membrano-cystic" lesions in the adipose tissue of the whole body including bone marrow. Brain weighed 1,030 g. There was a mild convolutional atrophy at the frontal lobe. White matter was diffusely atrophic. Demyelination was limited to the frontal lobe, where only small number of perivascular sudanophilic lipid-laden macrophages were found. Fibrillary astrocytes were rather diffusely proliferated, consistent with sclerosing leukoencephalopathy. Many spheroids were found in the frontal and occipital deep white matters, and external capsule. Ultrastructural study of spheroid revealed increased amount of neurofilament, vesicles with free patchy dense materials and degenerated mitochondria, which were consistent with primary axonal degeneration.