The history, radiographs, and histology are all consistent with periosteal osteosarcoma.
Periosteal osteosarcoma is an extremely rare intermediate grade surface osteosarcoma that usually occurs in patients 15 to 25 years of age. Treatment is the same as intramedullary osteosarcoma and consists of neoadjuvant chemotherapy, surgical excision with reconstruction, and adjuvant chemotherapy.
Hillmann et al. evaluated the functional outcomes of patients with distal femoral or proximal tibial tumors reconstructed with either endoprostheses or rotationplasties. They found that while no statistical difference exists between the two cohorts, patients with rotationplasties tended to have a greater level of activity, more normal gait, and were more confident in their limbs than the endoprostheses cohort. The cosmetic concerns regarding rotationplasties tended to be the largest problem with this method of surgical reconstruction.
Manoso et al. review their experience treating osteosarcoma in patients over the age of 40. They found that while historical references suggest no benefit to multimodal chemotherapy, their cohort treated with chemotherapy had a longer overall survival. As such, they now recommend multimodal chemotherapy to patients with osteosarcoma over the age of 40.
Kawai et al. performed a retrospective review on 40 consecutive patients treated with wide excision and reconstruction. They found in univariate and multivariate analysis that the independent adverse prognostic factors for prosthetic survival were male gender, resection of at least 40 per cent of the femur, and fixation of the femoral stem with cement. Aseptic femoral component loosening of the femoral component, necessitating revision, was the most frequent mode of failure.
Figure A and B are radiographs that shows a classic "sun-burst" appearance with an aggressive bone-forming lesion in the distal femur consistent with an periosteal osteosarcoma. Figure B is a MRI that shows the periosteal reaction and extension of tumor out of the medullary canal in the proximal diaphysis. Figure D is a histology slide that shows atypical malignant cells on a background of malignant osteoid. Illustration A is a radiograph showing surgical reconstruction following osteosarcoma resection. Illustration B shows a rotationplasty.
Hillmann A, Hoffmann C, Gosheger G, Krakau H, Winkelmann W. Malignant tumor of the distal part of the femur or the proximal part of the tibia: endoprosthetic replacement or rotationplasty. Functional outcome and quality-of-life measurements. J Bone Joint Surg Am. 1999 Apr;81(4):462-8.
PMID:10225791 (Link to Abstract)
Manoso MW, Healey JH, Boland PJ, Athanasian EA, Maki RG, Huvos AG, Morris CD. De novo osteogenic sarcoma in patients older than forty: benefit of multimodality therapy. Clin Orthop Relat Res. 2005 Sep;438:110-5.
PMID:16131878 (Link to Abstract)
Kawai A, Muschler GF, Lane JM, Otis JC, Healey JH. Prosthetic knee replacement after resection of a malignant tumor of the distal part of the femur. Medium to long-term results. J Bone Joint Surg Am. 1998 May;80(5):636-47.
PMID:9611024 (Link to Abstract)