Combined radiology and cytology in the diagnosis of bone lesions: a retrospective study of 370 cases.

Abstract

BACKGROUND Some of the risks with open biopsy can be avoided by fine-needle aspiration biopsy. The diagnostic contribution of radiologic findings has not been systematically studied. PATIENTS AND METHODS We retrospectively analyzed the validity of combined radiology and fine-needle aspiration cytology for the diagnosis of bone lesions in a consecutive series of 370 patients. The treatment diagnosis was based solely on radiology and cytology in 234 cases, whereas in 136 cases histopathology was also applied. RESULTS Comparison of radiology and cytology showed diagnostic compliance in 256 cases (69%) and non-compliance in 101 (28%). 13 (3%) cases failed to yield diagnostic material for cytology. Among the 256 compliant cases, the diagnostic error rate was 1% (2 were falsely benign), whereas the corresponding rate was 17% among the 101 non-compliant cases. In the latter group, 36 cases yielded only normal cells at aspiration, out of which 20 proved to have a neoplastic lesion (8 metastases, 12 benign). The overall sensitivity of cytology alone in recognizing malignancy was 90%. The specificity was 95%. Given a malignant or benign diagnosis, the positive predictive value was 97% and the negative predictive value was 84%. INTERPRETATION Our study suggests that a simple approach based on conventional radiography and fine-needle aspiration cytology offers a valid means of diagnosing bone lesions. Provided there is compliance between radiology and cytology, the risk of false diagnosis is around 1%.