Figure 7d. Adult GCT in a 68-year-old woman. (a, b) Axial T2-weighted (a) and sagittal T1-weighted (b) MR images demonstrate a multilocular cystic mass (arrows) with relatively thick septa. The septa have low signal intensity on the T2-weighted image (a). The signal intensity of the fluid within the cysts is very high on the T1-weighted image (b), a finding indicative of hemorrhagic contents. Compared with those seen in healthy postmenopausal women, the uterus is bigger and the endometrium is brighter on the T2-weighted image (arrowheads in a). (c) Sagittal contrast-enhanced T1-weighted MR image obtained with fat saturation shows that the septa have intense enhancement (arrows). A multilocular hemorrhagic mass was removed. (d) High-power photomicrograph (H-E stain) shows cells with oval and angular nuclei and scanty cytoplasm proliferating in trabeculae and cords separated by fibrous tissue. Some red blood cells are also seen, a finding that corresponds to the hypervascular nature evident at imaging. This case demonstrates the most common imaging appearance of GCT—a microfollicular pattern. The elevated serum estradiol level (69.6 pg/mL [255.4 pmol/L]) returned to normal (<8 pg/mL [29.4 pmol/L]) after surgery.