To report two cases of giant cell angiofibroma in the orbit.

(Case 1) A 17 ‐ year ‐ old girl was referred for evaluation of the left upper eyelid swelling which had developed 6 months ago. On initial examination, a 1.5 cm sized ovoid and nontender mass was palpated in the medial aspect of the left orbit. CT scan and MR imaging of the orbit showed a non-calcified, well-circumscribed homogenous soft tissue mass, which was uniformly enhanced and did not invade the adjacent tissue. Excisional biopsy of the orbital mass was performed. (Case 2) A 30 ‐ year ‐ old man presented with left proptosis which had developed 2 months ago and hemorrhage into the upper and lower eyelid which had developed 1 week ago. CT scan and MR imaging showed an heterogeneously enhancing mass, not involving the adjacent tissue in the superior retrobulbar space. Excisional biopsy through a lateral orbitotomy was performed. Histologic evaluation revealed proliferation of spindle cells with pseudovascular spaces and multinucleated giant cells.Immunohistochemical staining for CD34 and vimentin was positive and staining for CD31, smooth muscle actin was negative. A diagnosis of giant cell angiofibroma was made.

The possibility of giant cell angiofibroma should be considered in the differential diagnosis for an orbital mass without a hemorrhage or with a hemorrhage in the eyelid in adult patients.