Development of a desmoid tumor at the site of a total hip replacement.

Extra-abdominal desmoid tumors are locally aggressive benign soft tissue tumors arising from the connective tissue of muscle and overlying fascia or aponeuroses. Location around the hip occurs in about 10% of all desmoid tumors. The authors report the development of a desmoid tumor around the hip 45 months after implantation of a total hip prosthesis. Endocrine and physical factors seem to play an important role in the development of the disease. Moreover, an association has been reported between trauma and desmoid tumor. Desmoid tumors developing around silicon implants have also been described. However, no association between hip prostheses and desmoid tumors has been published in the world literature. Although soft tissue tumors induced by metallic implants have been observed clinically, we still seek a coherent explanation for the exact pathogenesis.