Spinal dermoid cyst manifesting with acute urinary retention: CT and MR imaging findings

Spinal dermoid cysts are rare congenial lesions resulting from inclusion of electrodermal elements at the time of closure of the neural groove in the third to fifth week of embryonic life. A dermal sinus, present in over 20% of spinal dermoids, is very helpful in the differential diagnosis. If the dermal sinus is absent, the images on CT and MR are similar to those of spinal lipoma, as this case clearly illustrates.