Osteosarcoma and the role of fine‐needle aspiration. A study of 51 cases

Fifty-one patients were evaluated by fine-needle aspiration (FNA) as part of the diagnosis, staging, and management of osteosarcoma. All patients had histologic confirmation of osteosarcoma. Five patients underwent two aspirations each; the total number of aspirates reviewed was 56. Aspirations were performed by interventional radiologists using fluoroscopic guidance. The cytologic features of osteosarcoma were divided into five groups: (1) pleomorphic (malignant fibrous histiocytoma-like); (2) epithelioid; (3) chondroblastic; (4) small cell; and (5) mixed. Although osteoid-like material was seen, it could not be distinguished readily from dense collagen. The chondroid matrix of chondroblastic osteosarcoma was recognized as a granular film with scattered clear bubbles. Fine-needle aspiration was diagnostic of sarcoma in 45 of 56 aspirates (80.4%). In eight aspirates, the cellularity of the smears was insufficient for diagnosis due to extensively osteoblastic tumors (six), necrotic tumor (one), and undetermined causes (one). In three aspirates, failure was attributed to poor cellular preservation due to unknown factors. The authors conclude that FNA is a useful tool in the multidisciplinary diagnosis and management of osteosarcoma. Aspirates should only be evaluated with full knowledge of the clinical and radiographic findings. The most significant limitation of FNA is the inability to detect osteoid.