PMC6122280_01
Computed tomography with intravenously administered contrast showed an inhomogeneously enhanced, intramedullary mass at the level of L3 [(a) left column, arrowhead]. The patient was subjected to hemilaminectomy and total excision of the mass was achieved [(b) right column]
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F1
Intraoperatively, a mulberry-shaped and purplish in color mass was recognized. The tumor was tightly adhered to a nerve root of the cauda equina
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F2
Macroscopically, the tumor was mulberry-shaped, purplish in color, and well demarcated, but tightly adhered to a nerve root of the cauda equina [Figure 2].
Histologic examination of the excised tissue revealed the presence of dilated cavernous vessels (image a, H and E, x4) lined by endothelial cells without indications of atypia (image b, CD34 immunohistochemistry, magnification x4; image c, CD31 immunohistochemistry, magnification x10; image d, ERG immunohistochemistry, magnification x10). Proliferation of cells as demonstrated by Ki-67 was scarce (image e, magnification x10)
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F3
Of interest, in the periphery of the mass, neurons of the peripheral nervous system were seen [Figure 3]. Immunohistochemical examination of the specimen demonstrated that the endothelial lining was composed of a rich network of cavernous vessels (CD34 - Figure 3b, CD31 - Figure 3c, ERG - Figure 3d). The tissue stained negative for prostate cancer (PSA, PSAP), melanoma (HMB-45, S-100), lymphoma (D2-40), meningioma (EMA, progesterone receptors), and Kaposi's sarcoma (HHV-8) markers; it also demonstrated a low mitotic index (Ki-67 2-3%, Figure 3e).