I-131 uptake in an ovarian tumor: differential diagnosis for abdominal I-131 uptake.

A 69-year-old woman was seen with well-differentiated papillary thyroid cancer with metastases in the neck lymph nodes, which was treated twice with 200 mCi (7.4 GBq) I-131. Several diagnostic scans during the next 12 years were negative. The last diagnostic scan with 8 mCi (300 MBq) I-131 revealed a large focus of I-131 uptake in the abdomen. An ultrasound was performed and was compatible with a large anechoic septal mass (21 × 16 × 9 cm) in the right side of the abdomen. Laparotomy with intraoperative evaluation and intraoperative histologic procedure confirmed ovarian granulosa cell tumor.