Osteogenesis with hematopoiesis simulating infection in a hydroxyapatite orbital implant.

A 28-year-old woman underwent secondary orbital implant surgery with placement of a hydroxyapatite implant. Over the next 7 years she underwent 3 drilling procedures. She began having copious discharge 1 year after the last drilling procedure. She was seen on numerous occasions with socket discharge, unresponsive to a variety of topical and oral antibiotics. Clinically, with the conjunctiva diffusely inflamed, the implant tender to touch, and the presence of a pyogenic granuloma, implant infection was suspected and the implant subsequently removed. Histopathologic assessment revealed widespread lamellar bone formation, including focal areas of marrow with active extramedullary hematopoiesis. There was no evidence of an inflammatory process or infection. Postoperatively the patient's symptoms and signs resolved. Extramedullary hematopoiesis within hydroxyapatite implants is rare. Porous orbital implant infection is also rare. Osteogenesis with extramedullary hematopoiesis simulating implant infection has not previously been reported.