Figure 17a. Leiomyosarcoma in a 44-year-old woman. (a) Sagittal T2-weighted image shows a tumor (M) with slightly high signal intensity and irregular margins. The tumor protrudes from the posterior myometrium into the endometrial cavity (arrows). Small leiomyomas (m) with clear margins are present in the anterior wall. (b) Sagittal T2-weighted image, obtained 3 months later after the patient experienced rapidly progressing abdominal fullness, shows an irregularly shaped uterus that has clearly increased in size. The tumor occupies the endometrial cavity (arrows). The nodules (m) in the anterior wall also demonstrate remarkable increase in size.