Background: The biopsy is a simple but critical step in the diagnosis of the musculoskeletal lesions. Although the open
incisional biopsy traditionally has been considered the gold standard with high diagnostic accuracy, an alternative, the closed needle biopsy (CNB), has been developed and widely used as it can be performed at an outpatient clinic under local anesthesia or in combination with the image guidance. In the present study, the authors purpose to study the diagnostic accuracy of CNB without real-time image-guidance at an outpatient clinic by comparing it with open incisional biopsy in musculoskeletal sarcoma patients.
Material and Method: The authors retrospectively reviewed 200 biopsy cases of sarcoma patients since 2002-2011. There were 105 cases of open incisional biopsy 105 cases and 95 cases of CNB. The diagnostic accuracies of both mentioned methods were compared statistically in four aspects of histopathology: nature (benign or malignant), specific diagnosis, histological type and histological grade. The gold standard was a final pathological diagnosis of the resected specimens received from definite surgery correlated with clinical findings and imaging studies.
Results: The diagnostic accuracies of open incisional biopsy were 97.14% for nature, 89.52% for specific diagnosis, 89.52% for histological type, 88.57% for histological grade and the diagnostic accuracies of CNB were 96.84%, 89.47%, 88.42%, 86.32%, respectively. There was no significant statistical difference between the two methods in all histological aspects (pvalue >0.05). The diagnostic yields of both methods were 98.13% for open incisional biopsy, 97.94% for CNB and there was no significant statistical difference (p-value >0.05). There were 6 cases (3%) for overall major errors, 3 cases (2.86%) from open incisional biopsy and 3 cases (3.16%) from CNB. There were 18 cases (9%) for minor errors, 9 cases (8.57%) from open incisional biopsy and 9 cases (9.47%) from CNB. There was no biopsy related complication in either method.
Conclusion: The office-based CNB diagnosis of musculoskeletal sarcoma can achieve an acceptably high diagnostic accuracy rate compared with open incisional biopsy.

Keywords: Close needle biopsy, Musculoskeletal sarcoma, Diagnostic accuracy