Parosteal lipoma. Report of 15 new cases and a review of the literature.

The lipoma is the most common tumor of the body and can be found in virtually every tissue or organ. However, a parosteal lipoma is a rare benign fatty neoplasm having an intimate relationship to the periosteum. The incidence of this tumor is 0.3% of all lipomas. Over 150 cases of parosteal lipoma have previously been described in the literature. Owing to the rarity of this condition and the difficulties encountered in its diagnosis and treatment, we wish to report fifteen new cases of parosteal lipoma. We reviewed the clinical records of 15 patients who underwent surgery to remove a parosteal lipoma between November 2003 and July 2009. The diagnosis of a parosteal lipoma was made by the histological findings, the confirmation of fat content at Magnetic Resonance or Computed Tomography. Surgery in all the cases entailed resecting the tumor with parosteal excrescence. In three cases with hyperostosis, a further exeresis of the bone was performed. Parosteal lipomas are rare entities associated with periosteal involvement depending on their location. Current management should include computed tomographic scanning and magnetic resonance. Surgery, which is mandatory treatment, requires particular attention to ensure that any periosteal involvement is removed completely.