Figure 6b. Cellular leiomyoma in a 28-year-old woman. (a) Axial T2-weighted fast SE MR image shows a well-circumscribed, heterogeneous leiomyoma on the left side of the uterine body (arrow). (b) Photomicrograph (original magnification, x100; hematoxylin-eosin stain) shows a uniform cellular neoplasm composed of whorls of smooth muscle cells with little intervening collagen.