Primary Intraosseous Cavernous Hemangioma of the Zygomatic Bone.

Purpose We present an uncommon case of primary intraosseous cavernous hemangioma involving the zygoma which displayed CD31 positivity on pathologic analysis. Observations Macroscopic examination showed a bulging purple-red mass intrinsic to bone measuring 2.1 x 1.8 x 1.6 cm (Fig 2A). Histopathology demonstrated the lesion was comprised of thin-walled vascular channels lined by a monolayer of endothelial cells interspersed among bony trabeculae (Fig 2B) consistent with intraosseous cavernous hemangioma.7,8 Vascular walls lacked both venous and arterial features. Immunohistostaining demonstrated endothelial cells positive for CD31 (Fig 2C, black arrow), a histologic feature sensitive and specific for vascular endothelial cell differentiation.9 At three months follow up our patient had excellent cosmetic results, normal afferent visual function, and normal ocular motility without recurrence. Conclusions and Importance Primary intraosseous cavernous hemangioma of the zygoma is a rare benign orbital bone tumor that commonly presents as a painless mass causing facial asymmetry. Complete en bloc resection in this case with a modified Medpor implant yielded an excellent postoperative functional and aesthetic outcome. While hemangiomas are the most common orbital soft tissue neoplasm, it should additionally be considered in the differential diagnosis of bony tumors of the zygoma.