Pathologic findings of interdigital neuroma. A, Interdigital nerve is greatly thickened by perineural fibrous tissue (hematoxylin and eosin stain). B, Vessels in region often show degenerative changes such as fraying and duplication of internal elastic lamina (Verhoeff-van Gieson stain). C, Some axons are missing, and others show degenerative changes (Bielschowsky stain). D, Small bursa may be found in region (hematoxylin and eosin stain).