Magnetic resonance imaging of ruptured spinal dermoid tumors with spread of fatty droplets in the central spinal canal and/or spinal subarachnoidal space.

OBJECTIVE: To evaluate magnetic resonance imaging (MRI) features of ruptured spinal dermoid tumors with spread of lipid droplets in the central spinal canal and/or spinal subarachnoid space and to understand the underlying mechanism.
METHODS: The MRI features of 12-ruptured spinal dermoid tumors were retrospectively analyzed. A literature review was performed to analyze the reported cases of ruptured spinal dermoid tumors along with our cases.
RESULTS: The locations of dermoids in our series are all at or below T12 level. Of the 12 cases, 10 ruptured into the central spinal canal, 1 ruptured into the central spinal canal as well as the subarachnoid space, and 1 ruptured into subarachnoid space only. Free lipid droplets exhibited hyperintensity on T1 weighted images, hypointensity on T2 weighted images, and low signal on fat-suppression sequence.
CONCLUSION: Spinal dermoid tumors ruptured into central spinal canal and/or spinal subarachnoid space have unique MRI features. The absorption of lipid droplets within central spinal canal is rather difficult, and their movement is extremely slow. We propose that fatty components within the central canal of spinal cord may be partially associated with spinal dermoid tumors developmentally.