Parosteal lipoma with hyperostosis: report of two pathologically proven cases evaluated by magnetic resonance imaging.

The authors describe two cases of parosteal lipoma, an infrequent benign tumour, associated with hyperostosis. The first patient presented with a mass in the posterior neck, the other with one in the proximal forearm. Radiologic diagnosis was facilitated by magnetic resonance imaging (MRI). The MRI images showed the characteristic features of a parosteal lipoma, as well as hyperostotic areas that remained of low signal intensity in both T1-weighted and T2-weighted sequences. MRI is both sensitive and specific for diagnosing these lesions and provides excellent depiction of the anatomic features before surgery.