RESUMEN
Sixty patients with clinically suspected bone tumour admitted to Yangon Orthopedic Hospital from 1992 March to 1993 July were examined by closed (Trephine needle) biopsy. The results of closed (needle) biopsy were compared with open biopsy results. Of the (60) cases, (30) were benigh and (30) were malig-nant including osteosarcoma, chondrosarcoma and metastatic carcinoma of bone. (97 percent) sensitivity, (93 percent) specificigy, (4 percent) false negative, no false positive and (95 percent) accuracy for closed (needle) biopsy of bone tumour were statistically analysed from this study. A good discrimination could be made between benign and malignant lesions and at times it is very useful to diagnose inflammatory conditions. Inspite of the drawbacks of inadequate samples and false negative results, it is found that closed (needle) biopsy is a simple, safe and reliable diagnostic method and is valuable in diagnosis of bone tumour and subsequent management.