[Brain warts]

26% of the brains studied (108) reveal warty extraversions which predominantly lie within the limits of the frontal lobe where they can be most frequently encountered on the lower frontal gyrus. Most of them occupy the crest of a gyrus. Only a few elongated ones can be found in the vicinity of the bottom of a sulcus. The various laminae of the cortex are subjected to variations. The molecular layer (I) contains a great number of ectopic nerve cells. Pigment-laden stellate cells and those devoid of pigment inclusions can be encountered besides a great number of various types of pyramidal cells. The nerve cells of the corpuscular layer (II) appear loosely arranged. The pyramidal layer (III) follows the curvature of the wart but appears attenuated towards its tip. Both the ganglionic layer and the multi-form layer show a lens-shaped thickening. If compared with an equal-sized part of the adjoining normal isocortex there is no numerical increase of nerve cells within the wart.