Intraosseous Epidermoid Cyst in the Femur After an Open Fracture: A Case Report.

Abstract

An intraosseous epidermoid cyst is a rare lesion usually arising from a phalanx in the hand or foot or from the skull1-5. To the best of our knowledge, only one case of an intraosseous epidermoid cyst involving the femur previously has been reported in the literature6. In this case report, we present the clinicopathological features of an intraosseous epidermoid cyst after an open fracture of the femur; we also review previous reports to discuss the etiology and treatment options for intraosseous epidermoid cysts. The patient was informed that data concerning the case would be submitted for publication, and he provided consent. A sixty-four-year-old man had sustained an open fracture of the right femur (Gustilo-Anderson grade IIIA) eleven years previously. After emergency debridement, he had been managed with intramedullary nailing and bone-grafting. After union of the fracture had been achieved, the clinical course was uneventful. Eleven years after the initial surgery for the fracture, the patient was seen at the local hospital with increasing pain in the right thigh. A radiograph showed an osteolytic lesion around the intramedullary nail in the epiphysis of the distal part of the right femur (Fig. 1). The intramedullary nail was extracted, and an open biopsy was performed. The biopsy specimen confirmed the diagnosis of an epidermoid cyst in the femur. An intralesional excision of the cyst was performed, and beta-tricalcium phosphate (β-TCP) (OSferion; Olympus, Tokyo, Japan) was implanted (Fig. 2). Fig. 1 Radiograph showing intramedullary nails and osteolysis in the epiphysis of the distal part of the femur. Fig. 2 Radiograph after the intralesional excision of the cyst and the implantation of β-TCP. Seven months after the second surgery, pain in the right thigh returned. On physical examination, diffuse swelling and heat (calor) were found in the distal aspect of the right …