View larger version (305K)

Figure 4d.   Mature cystic teratoma of the right ovary in a 19-year-old pregnant woman. (a) Sagittal transabdominal US image shows an echogenic mass with sound attenuation (arrows). (b) T1-weighted gradient-echo MR image (200/4.2) shows the mass (thick arrow) with high-signal-intensity fat (F). Low-signal-intensity central calcifications are also seen (thin arrow). (c) On a fat-suppressed T1-weighted gradient-echo MR image (200/2.1), the signal of the lipid material within the mass is suppressed (arrow). (d) Photograph of the gross specimen shows yellowish, pasty sebaceous material (black arrowhead) and hair (white arrowheads) within the cyst cavity, findings that account for the fat echogenicity and signal intensity seen at US and MR imaging. Two molar teeth are also evident (arrows).