The "Eagle Ray Sign" of the lumbar epidural space: A case of vascular-dominant spinal angiolipoma mimicking Aetobatus spp. morphology with favorable outcome and literature review.

INTRODUCTION/RESEARCH QUESTION: Spinal epidural angiolipomas (SEALs) are rare, benign mesenchymal tumors composed of mature adipocytes and anomalous vascular channels, representing only 0.04-1.2% of all spinal tumors. This study presents a rare case of a lumbar SEAL and proposes the "Eagle Ray Sign" as a morphological descriptor to characterize its unique macroscopic appearance during surgical resection.

MATERIAL AND METHODS: A 32-year-old woman presented with a history of insidious, progressive, and mechanically induced low back pain. Diagnostic evaluation included lumbar CT, MRI, and spinal cord angiography. Total surgical resection was performed via a bilateral L2-L3 laminectomy, followed by definitive histopathological analysis.

RESULTS: MRI revealed a posterior epidural mass with T1 hyposignal and T2 hypersignal, showing marked homogeneous enhancement. Preoperative angiography demonstrated no tumor blush, suggesting a discrepancy between MRI enhancement and actual vascularity. Intraoperatively, the resected en bloc specimen exhibited a distinctive morphology resembling a duckbill eagle ray (Aetobatus spp.). Histology confirmed a benign proliferation of mature adipocytes and dilated capillary structures. Postoperatively, the patient achieved complete resolution of symptoms.

DISCUSSION AND CONCLUSION: While SEALs typically favor the thoracic region, they should be considered in the differential diagnosis of lumbar compressive lesions. The proposed "Eagle Ray Sign" serves as a memorable macroscopic descriptor rather than a preoperative diagnostic tool. Gross-total surgical excision remains the definitive treatment, offering an excellent functional prognosis and high rates of long-term remission.