Critical evaluation of fine needle aspiration cytology as a diagnostic technique in bone tumors and tumor-like lesions

Abstract

Background: Though open surgical biopsy is the procedure of choice for the diagnosis of bone tumors, many disadvantages are associated with this approach. The present study was undertaken to evaluate the role of fine needle aspiration cytology (FNAC) as a diagnostic tool in cases of bony tumors and tumor-like lesions which may be conducted in centers where facilities for surgical biopsies are inadequate. Methods: The study population consisted of 51 cases presenting with a skeletal mass. After clinical evaluation, radiological correlation was done to assess the nature and extent of each lesion. Fine needle aspiration was performed aseptically and smears were prepared. Patients subsequently underwent open surgical biopsy and tissue samples were obtained for histopathological examination. Standard statistical methods were applied for analysis of data. Results: Adequate material was not obtained even after repeated aspiration in seven cases, six of which were benign. Among the remaining 44 cases, diagnosis of malignancy was correctly provided in 28 (93.3%) out of 30 cases and categorical diagnosis in 20 (66.67%). Interpretation of cytology was more difficult in cases of benign and tumor-like lesions, with a categorical opinion only possible in seven (50%) cases. Statistical analysis showed FNAC with malignant tumors to have high sensitivity (93.3%), specificity (92.9%) and positive predictive value of 96.6%, whereas the negative predictive value was 86.7%. Conclusion: FNAC should be included in the diagnostic workup of a skeletal tumor because of its simplicity and reliability. However, a definitive pathologic diagnosis heavily depends on compatible clinical and radiologic features which can only be accomplished by teamwork. The cytological technique applied in this study could detect many bone tumors and tumor-like conditions and appears particularly suitable as a diagnostic technique for rural regions of India as other developing countries.