Epithelioid haemangioma of bone: A series of four cases with a revision of this contentious entity.

Epithelioid hemangioma of bone is a rare and locally aggressive vascular neoplasm of bone associated with a good prognosis. Because of its worrisome histomorphologic features and aggressive clinicoradiologic findings, at times with multifocal presentation, they tend to simulate malignant tumors. We report a series of four cases of epithelioid hemangioma of bone with their clinicopathologic characteristics. All had adjacent soft tissue involvement and two had multifocal bone disease. Microscopically, all cases had a tumor in lobular configuration, composed of epithelioid endothelial cells with the formation of well-formed vessels or grew in solid sheets. The tumor cells lacked significant cytologic atypia, necrosis, and increased mitosis. All cases were immunohistochemically positive for vascular markers CD34, CD31, ERG1, whereas negative for CK. Two of the cases were treated with excision, and the other two underwent curettage. None had local recurrence or metastasis on follow-up. This study highlights the importance of recognizing histomorphological and clinicoradiological features for distinguishing epithelioid hemangiomas from malignant vascular neoplasms of bone because of their distinct therapeutic implications and clinical outcomes.