Isocortical pathology in type C Niemann-Pick disease. A combined Golgi-pigmentoarchitectonic study

A case of Niemann-Pick disease was examined with Golgi preparations and a transparent Golgi impregnation counterstained for intraneuronal pigment deposits. There was a specific type of storage of unmetabolized substrate restricted to certain nerve cell types. The most conspicuous changes in the isocortex were: 1) dilated axonal segments in layer IIIab pyramidal cells filled with storage material; the volume of these axonal expansions often exceeded that of the soma; 2) distension of layer IIIc, layer V, and layer VIa pyramidal cell perikarya with storage material; 3) new formation, elongation, and vertical orientation of basal dendrites in layer V pyramidal cells; 4) well-preserved pyramidal cells almost devoid of storage material and generally small in size were frequently found in layers II and IV, and to a lesser extent in layers III, V, and VI; 5) severe numerical reduction of small pigment-laden stellate cells in layers II and III; and 6) reduction of stellate cells devoid of lipofuscin pigment. These cells only occasionally contained small amounts of storage material.