Abdominal wall and surgical scar endometriosis: results of magnetic resonance imaging.

Scar endometriosis is a rare disease which is difficult to diagnose. The symptoms are nonspecific, typically involving abdominal wall pain at the time of menstruation. Clinical examination may reveal a painful nodule, if the scar involved is located on the abdominal wall, but is normal, when the lesion is located on the uterine scar. Other means of investigation (transvaginal ultrasonography, computed tomography) may be useful in case of lesions on the abdominal wall, or if the nodule is large, but give no specific results. The diagnosis is frequently made only after excision of the lesion. We report here 4 patients operated for scar endometriosis (two abdominal and two uterine scars) for whom MRI had suggested the diagnosis. Thanks to its very high spatial resolution, MRI enables very small lesions to be detected and can distinguish the hemorrhagic signal of endometriotic lesions. Furthermore, it performs better than the CT scan in detecting the limits between muscles and abdominal subcutaneous tissues.