Aneurysmal bone cyst-like areas as a sign of metastatic disease in the spinal column.

Aneurysmal bone cysts (ABCs) are vascular lesions with well-defined radiological signs. A fairly common MRI finding in both ABC and other primary bone tumors with high vascularity is the presence of cysts with fluid-fluid levels. Metastatic lesions with fluid-fluid leveling have not previously been defined in the literature. We report three cases of fluid-fluid leveling of the axial skeleton in metastatic lesions. Two patients had single-level and one multi-level neoplastic disease with distinctive cysts showing fluid-fluid levels on MRI evaluation. Diagnosis of gastric carcinoma in two patients and breast carcinoma in the third was achieved with trocar biopsies. At the time of this report all patients had completed initial oncologic treatments and were disease free.