Dermoid tumors are benign, rare congenital intracranial lesions which arise from the ectoderm. These tumors are seen as non-enhancing, low-density masses that may include peripheral calcification on computed tomography. On magnetic resonance imaging, these tumors are observed hyperintense on T1-weighted images, depending on the lipid content while they are heterogeneous hypo-hyperintense on T2 weighted images. Lipid fraction of these tumors lose their intensity in the fat-suppressed T1 sequences. Spontaneous rupture of dermoid tumors occurs in a small percentage of patients. When they are ruptured, fat droplets spread throughout the subarachnoid space and ventricular system. These fat droplets in the subarachnoid space and ventricular system are often seen as hypodens on computed tomography and as hyperintense on T1 weighted images on magnetic resonance imaging. Also, fat-liquid leveling in the ventricular system have a diagnostic value on magnetic resonance imaging. In this study, we present the computed tomography and magnetic resonance imaging findings of a ruptured parasellar dermoid tumor.
Key words: Dermoid; Ruptured; CT; MRI.
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