Cystic degeneration of a leiomyoma masquerading as a postoperative abscess

Leiomyomas are common tumors that usually have a typical sonographic appearance. With degeneration, however, the sonographic findings may be completely uncharacteristic. We report a case of a multicystic anterior uterine wall mass detected at antenatal sonography in an asymptomatic patient. Differential diagnosis included myoma, varicosity, hematoma, abscess, uterine anomaly, and pelvic neoplasm. At cesarean section, the mass was confirmed to be a myoma. Postoperatively, an ultrasound was performed by the radiology service during evaluation of suspected endometritis and the mass was interpreted as an endometrial abscess. This case illustrates that myomas can present with sonographic features consistent with a number of pathologic disorders. This variable pattern of echogenicity may sometimes create difficulty in establishing a correct diagnosis. The case also demonstrates the importance of communication between services and the need for not only antenatal but also postpartum and gynecologic ultrasound studies to be performed by physicians trained in sonographic findings of the abnormal uterus.