Clinical Presentation
A 30-year-old man presents with scattered areas of skin discoloration and soft-tissue masses along the right arm.
Imaging Findings
(A–C) Magnetic resonance (MR) images of the right arm reveal convoluted multinodular masses and thickening (long arrows) along the expected course of the radial nerve. The axial T2-weighted MR image shows high signal intensity peripherally (short arrow) with low signal intensity centrally (asterisk), the “target sign.”