2. CASE REPORT
A 19-year-old male presented with swelling, chronic pain and a palpable mass in the anteroinferior region of the left knee, and after examination with the help of lateral radiography of the left knee (Figure 1), with irregularities in the inferior of patella joint surface and multiple exostosis was observed in the patellar tendon region. The tumor lesion had sharp borders and a hyper-dense appearance, and no signs of fracture or dislocation were observed in the tibiofemoral and patellofemoral joints.
After surgery of the left knee joint, radical resection of the mass and proximal osteotomy of the left tibia, 3 irregular bone masses with total dimensions of 7 × 5 × 1 cm were sent for histopathological examination. In histopathological evaluation, well-differentiated trabeculae-spongy bone tissue, containing proliferated chondroid and osteoid areas in hypodense lacunae which covered with fibro-fatty tissue and thick hyaline cartilage was observed (Figure 2). This evaluation also confirmed multiple exostosis in the patellar tendon. After 3 months of follow-up, the patient had no movement disorders related to flexion and extension of the knee joint, pain and tumor lesion.