Intraneural ganglion: Review of the literature

Ganglions which occur in the nerves are named intraneural ganglion or nerve sheath ganglion. It should be considered in the differential diagnosis of any tumors causing neural disturbance. We review an intraneural ganglion, particularly arising in the common peroneal nerve with emphasis placed on usefulness of MRI for detecting this very unusual condition. MRI can clearly visualize a multilobular mass in the course of the nerve near the joint. The mass has low-signal intensities on T1-weighted images and homogenously high-signal intensities on T2-weighted images. The alteration of signal intensities of the muscles in the innervated compartments due to denervation is another finding for this unusual condition. During the surgery, dissection between ganglia and the nerve is difficult due to adhesions. Early diagnosis and treatment are recommended to prevent nerve damage.