Intrapelvic mass in a young woman with an uncemented hip arthroplasty

Based on a case report in which wear of the polyethylene liner in an uncemented hip prosthesis led to the development of an intrapelvic mass, the pathogenesis, diagnosis and treatment are described. Characteristic osseous and soft tissue reactions caused by release of polyethylene particles to periarticular tissue are discussed as well as the differential diagnosis with infectious and malignant conditions. In the case treated, the differential diagnosis was also made with respect to gynecological pathology.