Vascular Tumors of Bone

Epithelioid hemangioma of the acromion causing shoulder pain: a case report

“…EH of the bone has been reported several times in the literature [2][3][4][5][6][7][8]. The diagnosis of EH, particularly in osseous locations, remains challenging because of its atypical histologic features being confused with other epithelioid vascular neoplasms such as EHE or EAS.…”

“…Although accurate assessment of lesional histologic features is of paramount importance for differential diagnosis of these epithelioid vascular neoplasms, expression of immunohistochemical markers and genetic abnormality must also be considered. Immunohistochemically, EHs express typical endothelial markers including CD31, CD34, FLI-1, and ER [2,6,9]. Staining for smooth muscle actin demonstrates the presence of surrounding pericytes.…”

“…T2-weighted MRI will usually show well-defined lesions that are isointense or slightly hyperintense relative to skeletal muscle. There is variable surrounding marrow edema and enhancement and sometimes cortical disruption with periosteal reaction [2,6]. Histologic fea-…”

“…tures of EH include lobular proliferation of small, capillary sized vessels lined by large epithelioid endothelial cells with eosinophilic cytoplasm, infrequent mitoses, possibly small foci of necrosis, and stroma consisting of connective tissue sometimes with inflammatory infiltrates. Morphologically, it is difficult to distinguish between EH and EHE due to a considerable overlap at the pathological level, although EHE often shows infiltrative borders, arranges in clusters or cord-like structure, lacks inflammatory reaction, and often possesses myxoid or hyalinized stroma [2,6,9]. Although accurate assessment of lesional histologic features is of paramount importance for differential diagnosis of these epithelioid vascular neoplasms, expression of immunohistochemical markers and genetic abnormality must also be considered.…”

“…However, rarity and histological similarity with other vascular tumors have led to diagnostic difficulties. Moreover, because of the locally destructive clinical presentation and the presence of atypical histologic features with infrequent mitotic activity and necrosis, EH is often misdiagnosed as low-grade malignant epithelioid hemangioendothelioma (EHE) or high-grade malignant epithelioid angiosarcoma (EAS) [2,3]. EH of bone occurs as a benign tumor, and the treatment and prognosis differ from those of other malignant hemangioma tumors.…”