Figure 2.

Lipoma of the parietal peritoneum in a 53-year-old postmenopausal female presenting with acute abdominal pain. (a) Axial T1-weighted, (b) T2-weighted and (c) sagittal T2-weighted MR images show a solid mass (L) occupying the pelvic cavity and an atrophic normal-appearing uterus (U). Torsion of an ovarian tumor was suspected due to the slightly higher signal intensity on the T1-weighted image (a), which reflected hemorrhage, and the absence of contrast enhancement. Retrospectively, the identification of normal ovaries may have been hindered by age and menopause. Diagnostic surgery revealed a dark red, twisted (540° rotation) solid mass originating from the parietal peritoneum into the median pelvic cavity. (d) Pathologically, the tumor was diagnosed as a lipoma. The tumor was composed of a well-formed fibrous capsule and mature fat cells. The nuclei of the cells were necrotic due to torsion. MR, magnetic resonance.