Histopathologic evidence of fibrovascular ingrowth four weeks after placement of the hydroxyapatite orbital implant. We studied the histopathologic findings after placement of an orbital hydroxyapatite implant in a patient. The implant was placed after enucleation for a choroidal melanoma and was removed four weeks later because histopathologic examination of the enucleated globe disclosed tumor invasion of the optic nerve that necessitated further orbital tissue removal. Our histopathologic findings confirm that there is significant ingrowth of fibrovascular tissue in these implants, even within weeks of implantation. 