Fine needle aspiration (FNA) of bone tumours: with special emphasis on definitive treatment of primary malignant bone tumours based on FNA

Abstract

Although clinical and radiological examinations may present clues to the nature of bone lesions, bone tumours require morphological examination of tissue for definitive evaluation. Core needle biopsy and fine needle aspiration (FNA) are gradually becoming more accepted as a substitute for traditional open biopsy. There are several advantages to FNA. The procedure can be used safely in difficult sites such as the vertebrae or pelvis. Hospitalization is unnecessary, and a preliminary diagnosis can be rendered within 15–20 min of aspiration. This reduces patient anxiety and allows rapid triage with coordination of further investigations and discussion of anticipated therapy. Thin needle aspiration is less traumatic than either core needle or open biopsy. Tumour tracking is greatly reduced, limb-sparing surgery is facilitated, wound healing does not delay administration of chemotherapy and there is no significant risk of wound infection. Compared to core needle biopsy, FNA allows rapid preliminary diagnosis as well as aspiration from multiple areas in large tumours enabling an evaluation of tumour heterogeneity. There are also economical benefits; reduced hospitalization and operating room expenses. For most bone tumours, primary and metastatic, it is possible to base the definitive diagnosis on FNA. In addition to strictly defined cytological diagnostic criteria, adjunctive methods such as electron microscopy, immunocytochemistry, DNA-ploidy studies and cytogenetics may all contribute. As is true with open biopsy and core needle biopsy, however, the final assessment is based on combined clinical, radiologic and cytologic findings, necessitating close cooperation between the cytopathologist, orthopaedic surgeon and radiologist.