Photomicrographs of the osseous lesions. (A) Microscopic examination demonstrated ill-defined neoplasm composed of vascular lumen and endothelial cell proliferation forming glomerulus-like structures. (B) Delicate papillaries consisted of hyaline cores lined by prominent atypical nucleus and inconspicuous cytoplasm. (C) High-power photomicrograph demonstrated the characteristic “hobnail” appearance of the prominent endothelial cells. (D) Immunohistochemical staining showed the tumor cells strongly positive for CD31, but less positive for CD34 (E). Endothelial cells of lumens expressed D2-40, but the intraluminal tumor cells were negative for D2-40. (A, HE staining with original magnification × 100; B, HE staining with original magnification × 200; C, HE staining with original magnification × 400; D-F, immunohistochemical staining with original magnification × 200).
LI et al. Diagnostic Pathology 2013 8:160 doi:10.1186/1746-1596-8-160