A rare cause of neural foraminal widening.

The differential diagnosis for lesions causing neural foraminal widening is vast. The majority are solitary benign peripheral nerve sheath tumours, such as neurofibromas or schwannomas. We present a case of a rare cause of neural foraminal expansion secondary to a posterior thoracic extradural angiolipoma. We describe the presence of chemical shift artefact on post gadolinium T1-weighted imaging as indirect evidence of a fatty component. This potentially important diagnostic sign may raise the suspicion of angiolipoma, especially in an isointense or hypointense dumbbell lesion on T1-weighted imaging, and has not been described previously in this context. Accurate radiological diagnosis of an angiolipoma is important to reduce unexpected haemorrhagic complications from biopsy or resection of the lesion.