Malignant fibrous histiocytoma of the distal femur after an arthroscopic anterior cruciate ligament reconstruction: A case report and a review of the literature

Abstract

Background: Malignant degeneration in association with orthopaedic implants is a known but rare complication. To our knowledge, no case of osseous malignant fibrous histiocytoma after anterior cruciate ligament reconstruction is reported in the literature.

Case presentation: We report a 29-year-old male Turkish patient who presented with severe pain in the operated knee joint 40 months after arthroscopic anterior cruciate ligament reconstruction. X-ray and MR imaging showed a large destructive tumor in the medial femoral condyle. Biopsy determined a malignant fibrous histiocytoma. After neoadjuvant chemotherapy, wide tumor resection and distal femur reconstruction with a silver-coated non-cemented tumor knee joint prosthesis was performed. Adjuvant chemotherapy was continued according to the EURAMOS 1 protocol.

Conclusions: Though secondary malignant degeneration after orthopaedic implants or prostheses is not very likely, the attending physician should take this into consideration, especially if symptoms worsen severely over a short period of time.

Figure 1

Conventional X-ray imaging in anteroposterior (a) and lateral (b) projection show a 5.6 × 5 cm osteolysis of the medial femoral condyle with infiltration into surrounding soft tissue after arthroscopic anterior cruciate ligament reconstruction using the semitendinosus tendon.

Figure 2

Coronary (a) and transversally (b) T1-weighted MRI sequence shows a bone tumor spreading across the medial cortical bone and infiltrating into the vastus medialis muscle and the medial retinaculum. The graft and the femoral drill tunnel are not infiltrated by the MFH.

Figure 3

(a) shows the tumor biopsy with CD68 positive histiocytes (black arrows, 200-fold magnification), (b) shows the histological picture of a cell-rich mesenchymal tumor with storiform growth pattern, marked polymorphism, high rate of mitosis (black arrows) and marked angioneogenesis (*); HE, 200-fold magnification. (c) demonstrates the clear sm actin immunoreactivity (black arrow) of the tumor cells; anti-sm actin, 100-fold magnification.

Figure 4

Conventional X-ray imaging in anteroposterior (a) and lateral (b) projection after the implantation of a silver-coated non-cemented modular knee joint prosthesis (MUTARS).

Figure 5

Saggital section at the medial femoral condyle. It shows the presence of an intraosseous tumor of up to 4.8 cm in size (black arrow) with brown, partially myxoid cut surface.

Figure 6

(a) Histology of the resected tumor still shows good vascularisation (*) and moderate regression of the tumor tissue with about 25% vital cells (black arrows) after neoadjuvant therapy; HE, 100-fold magnification. (b) Strong trabeculae (*) and collagen fibres (Sharpey-like Fibers; black arrows) that attached the tendon graft tightly to the bone; HE, 50-fold magnification.

Figure 7

Coronary MRI sequence. Non-appearance of MFH before ACL rupture in 2006. Bone bruise in the lateral femoral condyle.