pubmed-article:3340305 | pubmed:abstractText | Electrophysiologic studies indicated a lesion of the deep branch of the ulnar nerve in the palm of a 42-year-old man with painless weakness and wasting of ulnar-innervated intrinsic hand muscles. Magnetic resonance imaging of this region demonstrated a soft-tissue mass in the palm distal to Guyon's canal. Surgical exploration disclosed a giant cell tumor of the tendon sheath, compressing the deep branch of the ulnar nerve. | lld:pubmed |