c

Fig. 11.111  (continued)

a

11.5.13  Inclusion Cysts

11.5.13.1\ Discussion

Cutaneously derived inclusion cysts or epidermoids can occasionally form within the spinal canal and cause pain and neurological deficits following a spine procedure. Most cases have been reported following myelomeningocele repair, although this complication can presumably result from any other procedure, including lumbar punctures, in which fragments of skin are introduced into the spinal canal. The cysts can grow and exert mass effect upon the nerve roots. MRI typically reveals low T1 and high T2 signal (Fig. 11.112). The presence of high signal on diffusion-weighted imaging can be helpful in distinguishing epidermoid from arachnoid cyst.

b

Fig. 11.112  Inclusion cysts. The patient has a history of prior myelomeningocele repair and presents with a lump at the surgical site. Sagittal T2-weighted (a) and T1-weighted (b) MR images show two well-defined,

ovoid cystic masses in the posterior spinal canal at the site of prior myelomeningocele repair. Sagittal DWI (c) and ADC map (d) show that the lesions display restricted diffusion