OBJECTIVE: To determine the predictive value of fine needle aspiration
cytology (FNAC) of bone lesions. STUDY DESIGN: The study consisted of
data retrieval on 200 cases of bone lesions and their cytohistopathol
ogic correlation to asses the diagnostic efficacy of FNAC in these cas
es, considering histopathology as the gold standard. The diagnostic in
dices were calculated by 17 decision matrix comparison. RESULTS: On cy
tohistopathologic correlation of 200 cases, 106 (53.0%) were malignant
bone tumors (MBT): 97 primary and 9 metastatic; and 76 were benign bo
ne lesions (BBL), 58 neoplastic (29%) and 18 nonneoplastic (9%). The a
spirated material was adequate in 181 cases, whereas in 18 cases cytoh
istopathologic examination revealed no bony lesion. Thus, there were 1
63 evaluable cases, of which the specific morphologic diagnoses on FNA
C were possible in 141 cases (86.5%), with 17 solitary false positive
and 8 false negatives. The percentage of inadequate aspirates teas mor
e with BBL (13.2%) than MBT (8.5%). The overall diagnostic accuracy an
d sensitivity of bone lesions were 95.0%, whereas specificity, positiv
e predictive value (PPV) and negative predictive value (NPV) were 94.7
%, 99.4% and 69.2%, respectively. The sensitivity of FNAC was better (
95.8%) with MBT as compared to BBL (91.7%), whereas specificity and PP
V were almost equal (98.8% and 99.2%) in both cases. The NPV in cases
of BBL was higher (97.8%) than in MBT (95.2%). These diagnostic indice
s were calculated excluding the inadequate cases. CONCLUSION: High PPV
and NPV indicate the relia bility of FNAC for the diagnosis of bone l
esions.