MR imaging of brown tumour with fluid–fluid levels: a report of three cases

Abstract.

Fluid–fluid levels on CT and MR imaging are a typical feature of aneurysmal bone cysts but have also been reported in many other osseous lesions containing haemorrhage. We report fluid–fluid levels in four brown tumour in three patients with primary hyperparathyroidism in which the initial radiological diagnosis was thought to be a bone tumour. To the authors' knowledge, this is the first time that association has been reported in the international literature.