The structure of the terminal villi was observed in placentae from non-diabetic mothers and mothers with diabetes mellitus using scanning and transmission electron microscopy. The metabolic condition of maternal diabetes was tightly controlled. In the diabetic group, the diameter of the terminal villi was significantly smaller than in the control group. The ramification pattern of villi, classified into hypo-, moderate-and hyper-ramifications, was shown to be mostly moderate in the non-diabetics whereas most of the diabetic placentae had either hypo-or hyper-ramifications. Mothers with a longer duration of diabetes and complicated with retinopathy tended to have hypo-ramification ; in these mothers, the weight of the neonates was significantly less than normal. Moreover, in the diabetic placentae, syncytial knots were found more frequently, the percentage of vasculo-syncytial membranes tended to be lower, and the trophoblastic basement membrane was significantly thicker than in the control. These abnormalities in the diabetic placentae were independent of the methods of delivery ; they seem to be related with fetal growth retardation and poor neonatal outcome, which are commonly seen in diabetic pregnancy. diabetic placenta ; electron microscopy ; quantitative investigation ; terminal villi
This report describes an unusual neuronal tumor detected at the autopsy of a 17-year-old boy. The tumor showed multifocal parenchymal involvement with extensive leptomeningeal dissemination. The intraparenchymal lesions were small and located mainly in the subpial region of the cerebrum, cerebellum and spinal cord. Leptomeningeal dissemination was particularly pronounced at the base of the brain and around the spinal cord and presumably took place during the relatively long clinical course. The tumor was composed of small round cells and ganglion-cell-like cells. Only neuronal differentiation, as represented by immunostaining with antisynaptophysin antibody and the presence of dense-core vesicles in the cytoplasm, was evident in both types of cells. The small round cells appeared to exhibit the features of small, relatively mature neurons rather than those of neuroblasts. Moreover, our results suggested maturation from small round cells to ganglion-cell-like cells. The tumor appears to be related to gangliogliomas or dysembryoplastic neuroepithelial tumors, and we have chosen the term neurocytoma/gangliocytoma for the unusual lesion.
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