Segmental solidification of the glomerular tuft by increased extracellular matrix, causing glomerular capillary obliteration is present at the vascular pole, involving less than 50% of the tuft. It can be accompanied by other descriptors such as hyalinosis, foam cells, hypertrophy of overlying glomerular epithelial cells, podocyte depletion, halo and adhesion of the tuft to the Bowman's capsule. [from
HPO]