Objectives:
Aneurysmal bone cysts (ABC) are vascular lesions with well-defined radiological signs. A fairly common MRI finding is the presence of cysts with fluid-fluid levels. This finding is also known to be associated with other primary bone-forming tumors of the bone with high vascularity. However, metastatic lesions with fluid-fluid levels have never been defined in the literature.
Patients and methods:
14 patients presenting with pain and/or neurological loss at three separate spinal centers were included in this study. Twelve had a single fluid-fluid level, and the others had various levels, on MRI.
Results:
Diagnosis was achieved with trocar biopsies in all patients, and aneurysmal bone cysts were established in 11 cases in accordance with radiological diagnosis (78.6%). Three of the patients (21.4%) had metastatic lesions. Two were diagnosed as gastric carcinomas and the third as breast carcinoma. At the time of this report, they had all completed their initial oncological treatment and were disease-free.
Conclusion:
Cysts with fluid-fluid levels may not be a feature only of primary bone tumors of the spinal column. This case study demonstrates that a high level of suspicion and biopsies may be warranted for all patients for definitive diagnosis.
Keywords: Aneurysmal bone cyst, metastasis, spine