Age / Sex : 61 / F

Chief complaint : Left lower extremity radiating pain (2YA)


What is your diagnosis?


Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).

Courtesy : 김보람 Bo Ram Kim, 분당서울대학교병원 Seoul national university Bundang hospital

Epidural angiolipoma

Discussion

Findings: 2.9 x 1.6 x 3cm size epidural mass at S1-2 level, Lt. side

 - Lt. S1 neural foraminal extension with bony remodeling

 - The major part of the tumor showed T2 high and T1 low signal intensity with prominent enhancement

 - internal fat component (+) with T1 hypersigntal intensity

Differential Diagnosis: Epidural hemangioma, epidural lipoma, neurogenic tumor, Lymphoma

Discussion: Spinal angiolipoma is a rare, benign tumor that accounts for approximately 1% of all spinal tumors and 2%–3% of extradural spinal tumors. The tumor was composed of adipose and vascular elements. The ratio of fat to vessels range from 1:3 to 2:3. The fat components were the same as the normal adipose. The blood channels were composed as capillary, sinusoidal, thin-walled or thick-walled vessels with proliferation of the smooth muscle, and occasionally well-developed small artery. The thin-walled blood vessels were mostly common seen and easily ruptured as the vessel wall was weak. Patient can be demonstrated as an intraspinal hematoma due to intratumoral bleeding. A majority of tumors have typical MR features and can be diagnosed easily, as the signal of the lesion can be divided into two parts: the fatty content which was hyperintense on both T1-weighted and T2-weighted images and hypointense on fat-suppressed images. The blood vessels showed to be hypointense in T1-weighted and hyperintense in T2-weighted with significant enhancement after the injection of contrast. Blood flow-void shadow is rarely seen because the well-developed intratumoral small arterial are seldom seen. Angiolipomas can be divided into infiltrating and non-infiltrating varieties, and both as seen in the epidural space. Non-infiltrating angiolipomas are more common and are usually located in the dorsal epidural space, typically in the thoracic region. Infiltrating angiolipomas are more common in the anterior epidural space, and can infiltrate not only adjacent soft tissues, but also adjacent vertebrae.

References:

Leu NH, Chen CY, Shy CG et-al. MR imaging of an infiltrating spinal epidural angiolipoma. AJNR Am J Neuroradiol. 2003;24 (5): 1008-11. AJNR Am J Neuroradiol

Hu S, Hu CH, Hu XY et-al. MRI features of spinal epidural angiolipomas. Korean J Radiol. 2013;14 (5): 810-7.