Pleomorphic Malignant Fibrous Histiocytoma at the Site of an Arthroscopic Reconstruction of the Anterior Cruciate Ligament

Abstract

P reviously regarded as a distinct tumor type representing the most common adult soft-tissue sarcoma1,2, the term malignant fibrous histiocytoma is now reserved for a small group of undifferentiated pleomorphic sarcomas3. The tumor is most often primary, but rare cases of secondary malignant fibrous histiocytoma in burn scars4-8 or infected or noninfected surgical scars9-12 have been reported (see Appendix). Secondary malignant fibrous histiocytoma has been described in contact with prostheses13-28, osteosynthesis material29-35, or implanted Dacron grafts36. Malignant degeneration of benign tumors35, Paget disease37, osseous infarcts38, or fibrous dysplasia39 also has been reported (see Appendix). We report a unique case of a patient with soft-tissue malignant fibrous histiocytoma that developed on the medial side of the knee six years after arthroscopic reconstruction of the anterior cruciate ligament with use of the patellar tendon. D uring a soccer game in June 1993, a nineteen-year-old man experienced an indirect injury to the right knee that caused a rupture of the anterior cruciate ligament. A magnetic resonance imaging scan confirmed the diagnosis. An arthroscopic reconstruction of the anterior cruciate ligament was carried out in October 1993 with use of the patellar tendon. Stainless-steel (alloy-316L) screws (with a diameter of 6.5 mm) were used for the femoral and tibial fixation. The rest of the intra-articular examination was normal, and the postoperative course was uneventful. In 1995, a hemarthrosis developed in the right knee subsequent to a new injury. The knee was stable, and the hemarthrosis resolved with symptomatic treatment. In 1997, the patient experienced a locking episode of the right knee, which was found to be caused by a bucket-handle tear of the medial meniscus at …