Computed tomography fluid-fluid level in bone metastasis

Fluid-fluid levels have been reported in a variety of primary bone and soft-tissue tumours, most frequently in aneurysmal bone cysts, but have never been reported in a metastatic bone lesion. To emphasize such a possibility the authors present a case in which serial computed tomography demonstrated a pulmonary nodule, paratracheal adenopathy and a fluid-fluid level within a rib lesion. Further investigation confirmed a rib metastasis from primary carcinoma of the bronchus.