Epidural angiolipoma
General description
Epidural angiolipomas are benign mesenchymal neoplasms composed of mature adipocytes intermingled with abnormal vascular channels. Epidural angiolipomas account for approximately 0.14%–1.2% of all spinal tumors and 2%–3% of extradural spinal neoplasms. They predominantly affect adults in the fourth to sixth decades of life, with a mean age at presentation around 50 years. A clear female predominance is noted in spinal cases, with reported male:female ratios ranging from 1:1.4 to 1:2.
References
- Lu, Taikun, et al. "Demographic and clinical data of patients with spinal epidural angiolipomas." Scientific Reports 14.1 (2024): 17473.
Spinal lesion
Margins of epidural angiolipomas are typically well circumscribed, often encapsulated in non-infiltrative subtypes, and exhibit a spindle-shaped, “pen-tip” appearance on sagittal MRI.
On CT, the lipomatous component demonstrates negative Hounsfield units (–37 to –110 HU), reflecting fat density, interspersed with regions of soft tissue attenuation corresponding to vascular stroma. Contrast-enhanced CT reveals heterogeneous enhancement confined to the vascular component.
MRI signal characteristics mirror the mixed composition of fat and vessels. The fatty regions are hyperintense on T1-weighted and T2-weighted sequences and suppress on fat-saturated or STIR images. The vascular elements are isointense to hypointense on T1-weighted images and hyperintense on T2-weighted images, with marked, often heterogeneous enhancement following gadolinium administration. No restricted diffusion has been reported in either spinal or intracranial angiolipomas, consistent with their benign, low-cellularity nature.