Figure 6b. Müllerian cyst in a 57-year-old woman. (a) Contrast-enhanced CT scan shows a well-defined cystic mass in the left retroperitoneal space (arrow). (b) Photomicrograph (original magnification, x40; H-E stain) shows the cyst lined by ciliated, cuboidal to low columnar epithelial cells resembling fallopian tube epithelium.