[A case of epidermoid carcinoma developing from contact with an articular hip prosthesis].

Several cases of sarcomas which developed in contact with joint prosthetic material were reported previously. They were mostly malignant fibrous histiocytoma, but to our knowledge, no case of epidermoid carcinoma was reported. We report here one case of epidermoid carcinoma which developed in contact with a hip prosthesis. Surgery was complicated by local infection and necessitated multiple reoperations, which may be responsible for the implantation of skin cells. It is generally admitted that multiple factors contribute to the development of a tumor clone. In our patient we must take into consideration such factors as chronic infection with fistula and prosthetic material. However carcinomas, even rare, which form on fistulas appear only after many years of suppuration. The short delay between the prosthesis setting and the carcinoma onset in our patients, suggests that a cofactor may have speeded up tumor induction. This cofactor could be the platelet derived growth factor (PDGF) in the case of sarcomas appearing on bone infarcts without foreign body introduction, and possibly other tumors.