Figure 11b. Focal adenomyosis mimicking a subserosal leiomyoma in a 42-year-old woman. (a, b) Axial (a) and coronal (b) T2-weighted fast SE MR images show a poorly marginated, heterogeneous mass (straight arrow) with punctate foci of high signal intensity (arrowhead) adjacent to the left side of the uterine body. There is mild thickening of the inner myometrium, a finding suggestive of adenomyosis. There is also a small, right-sided intramural mass, an appearance typical of a small leiomyoma (curved arrow in a). (c) Photomicrograph (original magnification, x40; hematoxylin-eosin stain) of the resected adnexal mass shows several islands of ectopic endometrial glands (*) surrounded by whorled hypertrophic smooth muscle.