Figure 4

Case 1. XP-A Axonal neuropathy and denervation atrophy of skeletal muscle. A: Electron microscopy showing mild to moderate reduction in the number of large myelinated axons accompanied by increased collagen and axonal degeneration and axonal atrophy consistent with axonal neuropathy. B: Skeletal muscle showing marked variation in fiber size, with rounded and angulated atrophic fibers, pyknotic nuclear clumps, fibrosis with fat replacement.