case_images: PMC7750753_01
case_images: Mild atrophy of the dorsal and palmar interosseous muscles was found in the left
  hand.
case_images: 10.1177_2050313X20972850-fig1.jpg
case_images: PMC7750753_01_10.1177_2050313X20972850-fig1.jpg
case_images: fig1-2050313X20972850
case_images: Atrophy of the dorsal and palmar interosseous muscles was found (Figure 1).
case_images: Axial view obtained using ultrasonography shows the occult ganglion (arrow) and the
  ulnar nerve (arrowhead) at the level of the medial epicondyle.
case_images: 10.1177_2050313X20972850-fig2.jpg
case_images: PMC7750753_01_10.1177_2050313X20972850-fig2.jpg
case_images: fig2-2050313X20972850
case_images: Axial view obtained using MRI shows the occult ganglion (arrow) inside the ulnar nerve
  (arrowhead) at the level of the medial epicondyle.
case_images: 10.1177_2050313X20972850-fig3.jpg
case_images: PMC7750753_01_10.1177_2050313X20972850-fig3.jpg
case_images: fig3-2050313X20972850
case_images: Netherlands; Figure 3) showed an occupied lesion inside the ulnar nerve at the medial epicondyle of the humerus. Nerve conduction study results indicated the motor nerve conduction velocity of the ulnar nerve on the affected side as 40.2 m/s between the upper elbow and the below elbow, compared to 54.4 m/s on the unaffected side.
case_images: (a) The ulnar nerve was compressed by the Osborn ligament over the flexor carpi ulnaris
  (FCU) (arrow). (b) Decompression was performed by releasing the Osborn ligament and FCU
  fascia. Neuroedema of the ulnar nerve (arrowhead) caused by compression was found at the
  proximal position of the fibrous bundle. (c) We tried to resect the small ganglion as en
  bloc. However, the ganglion was ruptured (arrowhead).
case_images: 10.1177_2050313X20972850-fig4.jpg
case_images: PMC7750753_01_10.1177_2050313X20972850-fig4.jpg
case_images: fig4-2050313X20972850
case_images: The ulnar nerve was compressed by Osborn's ligament, which was apparently harder and thicker than normal (Figure 4(a)). Neuroedema of the ulnar nerve caused by compression was found at the proximal position of the fibrous bundle (Figure 4(b)). However, the ganglion was ruptured (Figure 4(c)).