PMC9633206_01
Computed tomography scans in coronal (a, d), sagittal (b), and axial (c, e) views showing posterior vertebral scalloping changes of L3, L4, and L5 without erosion of the cortical and medullary bone (arrowheads) and the cavity of the posterior wall connecting the foramen (arrow). Schmorl's nodes at the endplates of L3, L4, and L5 are observed (circle).
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Computed tomography (CT) revealed posterior vertebral scalloping change of L3, L4, and L5 without erosion of the cortical and medullary bone and Schmorl's nodes at the endplate of the L3, L4, and L5 (Figure 1).
Magnetic resonance imaging on T1-weighted (a), T2-weighted (b), and T2-fat suppression (c) reveal a mass (circles) of high-signal intensity at the L4 pedicle level in the left epidural space. The following were observed: a hyperintense anterior epidural mass (arrows) with strangulation of the dural sac at L4-5 levels (the first row), epidural mass (arrowheads) at L4 compressed asymmetrically on the left side of the cauda equina, and exiting left L4 nerve root on axial T1- and T2-weighted images (d, e) (the second row).
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T1- and T2-weighted MRI (Figure 2) and gadolinium contrast-enhanced imaging (Figure 3). Thus, a spinal epidural lipoma was suspected with differential diagnoses of epidural tumor and neurinoma.
Contrast-enhanced MRI scans in coronal (a), sagittal (b), and axial (c, d) views reveal an epidural mass at L4/5 and bone defects with concentric rim of edema (circle) (hypointense in T1-weighted, hyperintense in T2-weighted and short tau inversion recovery (STIR)) in the endplates of the L3, L4, and L5 vertebrae and acute Schmorl's nodes.
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T1- and T2-weighted MRI (Figure 2) and gadolinium contrast-enhanced imaging (Figure 3). Thus, a spinal epidural lipoma was suspected with differential diagnoses of epidural tumor and neurinoma.
(a) Adipose tissue mass (circle) between the left L4 nerve root (arrow) and dural sac (arrowhead) intraoperatively. (b) Intraoperative echo image reveals the location of adipose tissue mass (circle) ventral to the dura, with no invasion to the intradural space.
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Moreover, the lipomatous mass was present along the left L4 nerve root (Figure 4) and tightly adhered to the epidural venous plexus and ventral dura mater; thus, it could not be easily detached.
Hematoxylin and eosin-stained microscopic findings ((a) x40 and (b) x100) confirm mature adipose tissue with large adipocytes enclosed by fibrous tissue (arrowheads), compatible with a lipoma.
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Histological examination of the encapsulated epidural mass showed lobulated mature adipose tissue enclosed by fibrous tissue, compatible with a lipoma (Figure 5).