Histopathological features of surgical samples taken from patients with Type IIb FCD. a, d, e: Examples of a severe lesion (parietal lobe): a, d (SMI immunoreactivity, ir) and e (NeuN ir) highlight typical features of Type II FCD, which is characterised by the total disruption of cortical lamination and the presence of numerous DNs throughout the cortex intermingled with fewer normal-looking neurons. j, k: Details of the regions marked with asterisks in d and e, respectively, show DNs that are clearly distinguishable by their very large size and abnormal shape (arrows). In the same case, vimentin-positive BCs (l) are diffusely distributed in the subcortical white matter. b, f, g: Examples of a less severe lesion (frontal lobe). b, f (SMI ir) and g (NeuN ir) showing cortical areas in which lamination is relatively preserved and DNs (arrows) are scattered in restricted cortical layers (deep layers) intermingled with numerous normal-looking neurons. m, n: Details of the regions marked with asterisks in f and g, respectively, show DNs (arrow) and normal-looking neurons. c, h, i: Examples of perilesional cortex (temporal lobe). c, h (SMI ir) and i (NeuN ir) showing normal cortex adjacent to the principal lesion. Scale bars: 3.8 mm (a); 2.5 mm (b); 3.6 mm (c); 540 μm (d, e); 450 μm (f, g); 414 μm (h, i); 120 μm (j, k, m, n); 4.68 mm (l) and 50 μm for inset in l.