Presentation
Myelopathic symptoms.
Patient Data
An intrathecal mass from T3/4 to T6/7, with a probable sizable intramedullary component, demonstrates hyperintense signal on both T2 and T1 sequences and fat saturation on fat-sat sequences.
On the post-contrast fat-saturated T1 sequences, however, regions of fat saturation at the superior margin of the abnormality demonstrate an enhancing component.
The lesion results in expansion of the cord. No syrinx of the imaged cord. No evidence on MRI of intralesional calcification. No surrounding prominent flow voids. No hemosiderin cap. No demonstrable bony remodeling or extrusion out the neural exit foraminae.
Conclusion: Intrathecal and almost certainly intramedullary lesion with heterogeneous morphology containing macroscopic fat and non-fatty, probably enhancing, components. The differential is therefore primarily between a mature teratoma or a lipoma complicated by hemorrhage. Absence of spinal dysraphism excludes a lipomyelocele.
The features are not those of an ependymoma, astrocytoma or other glial series spinal cord tumors.
Case Discussion
The patient went on to have a resection.
Histology
The pieces of tissue show sheets and lobules of mature adipocytes with a few larger vessels and some adjacent fibrous tissue. There is no nuclear atypia, mitoses or necrosis. Other mesenchymal elements are not present. There is no evidence of malignancy.
FINAL DIAGNOSIS: benign mature adipose tissue consistent with a spinal lipoma.