Intradural Extramedullary Epithelioid Hemangioendothelioma of the Thoracic Spinal Cord: A Case Report

Abstract

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor, and develops infrequently in the central nervous system. To our knowledge, this is the first case of EHE of the spinal cord. An 85-year-old man presented with about 6-month progressive myelopathy. Magnetic resonance imaging (MRI) demonstrated an oval-shaped intradural extramedullary mass at T10 level with extensive intramedullary edema. A reddish tumor was removed via a total laminectomy of T9-T10. Histologically, the tumor cells with nuclear atypia and active mitoses were immunopositive for vascular tumor markers, and formed a lobular architecture associated with capillary-sized vessels lined with edematous endothelial cells. Although very rare, EHE should be considered in the differential diagnosis of a spinal intradural extramedullary tumor.

Keywords: epithelioid hemangioendothelioma; spinal cord; vascular tumor.

Fig. 1. Preoperative spinal MRI (A–C, sagittal images; D–F, axial images). T1-weighted images (A, D) show an intradural extramedullary oval-shaped isointense lesion at T10 level, which is hyperintense on T2-weighted images (B, E) and has an intense peripheral ring enhancement with homogenous central enhancement by gadolinium (C, F). An extensive intramedullary hyperintense area is also revealed on T2-weighted images (B, E), and the part of the area in the spinal cord is enhanced at T10 level (arrow; F). MRI: magnetic resonance imaging.

Fig. 2. An intraoperative photograph through the surgical microscope (upper) and the illustration (lower). After dural opening, a reddish mass (asterisk) and some dilated veins (arrows) are found on the thoracic spinal cord.

Fig. 3. Histopathological findings. Hematoxylin and eosin staining (A) shows many capillary-sized vessels lined by endothelial cells and tumor cells with mitoses (arrows). Immunostaining shows that endothelial cells and tumor cells are positive for CD31 (B) and CD34 (C), and that nuclei of tumor cells are positive for ERG (D) and negative for STAT6 (E). MIB-1 index is approximately 32.6% (F). Scale bar = 25μm. ERG: erythroblast-transformation- specific-related gene.