Clinical outcome of 38 patients with juxtacortical osteosarcoma

Thirty-eight patients presented with previously untreated, predominantly lo w-grade juxtacortical osteosarcoma, There were 12 (32%) men and 26 (68%) wo men with a mean age of 28.9 years. The most common sites of tumor were the distal femur (n = 28) and proximal tibia (n = 5), Twenty-five patients pres ented with Stage LB tumors. Twelve had Stage IIB, which although it was pre dominantly low-grade, had an area of high grade tumor, so the tumors were c onsidered dedifferentiated. One patient had Stage III tumor, All patients w ere alive at 6.75 years' average followup, Negative but close margins were achieved in all but two patients (range, 1-80 mm), Intramedullary extension was seen in 17 (44.7%) patients, and the adjacent cortex was invoiced in 2 7 (71.1%) patients, There was no statistically significant difference betwe en tumor size, site, radiographic appearance, cortical or intramedullary ex tension, grade, resection margin, or pretreatment duration of symptoms and local recurrence. Intramedullary extension of tumor does not seem to increa se the risk of metastatic disease, Dedifferentiation of predominantly low-g rade juxtacortical osteosarcoma in not previously treated tumors is uncommo n, Based on these data, close but negative margins may be adequate in achie ving local disease control and preventing metastases in these patients.