Mesenteric liposarcoma or lipodystrophy: an elusive diagnosis.

Mass lesions of the mesentery may be fortuitously encountered on computerized tomographic (CT) scans, posing a diagnostic challenge. Despite CT, magnetic resonance (MR) imaging and a surgical biopsy, a patient with mesenteric lipodystrophy was misdiagnosed as having a low-grade mesenteric liposarcoma. Spontaneous regression of the mass on control CT scan and review of the pathological material prompted us to reconsider the diagnosis of malignancy. Because a wide variety of tumors and pseudotumors produce alterations in the density and volume of mesenteric fat on CT scan, a surgical biopsy is usually necessary to obtain a tissue-specific diagnosis, but even then pathological findings may be equivocal. As final resort the natural evolution assessed by radiological follow-up can be of help in determining the nature of the disease.