Incidental Scintigraphic Finding of Ovarian Teratoma Containing Normal Thyroid Tissue on Post–Radioactive Iodine Therapy for Papillary Thyroid Cancer

Abstract

Abnormal focal uptakes are often visualized on I post-treatment scintigraphy in case of differentiated thyroid carcinoma. For some of these, especially on atypical localization, it can be difficult to affirm the benign or malignant nature. A high serum thyroglubulin value after surgery may suggest the presence of metastatic disease. We report a case of an abnormal ovarian uptake on post-treatment scintigraphy associated with an elevated thyroglobulin value revealing finally an ovarian mature cystic teratoma containing normal thyroid tissue.

Abnormal radioiodine uptake on post-therapy whole body scan and sodium/iodine symporter expression in a dermoid cyst of the ovary: report of a case and review of the literature

“…Struma ovarii represent an uncommon but well known false-positive localization of 131 I (20)(21)(22), because it is mainly or exclusively composed of well-differentiated and functioning thyroid tissue, able to trap iodine as well as to produce thyroid hormones and thyroglobylin (18)(19)(20)(21)(22). Up to date, there are only four reports in the literature of radioiodine uptake by ovarian dermoid cysts, not be classified as struma ovarii (23)(24)(25)(26).…”

“…The pWBS demonstrated a focal uptake in the pelvis, that was found to be due to a typical dermoid cyst of the ovary (23). After this first report, three other cases were described (24)(25)(26). All were childbearing-age female patients, who have been previously undergone total thyroidectomy for DTC, two papillary and one follicular cancer.…”

“…In all patients, as in our, the ovarian lesion was clinically silent and previously unrecognized, and it was incidentally discovered on WBS in the follow-up of the thyroid cancer. The WBS showed an abnormal pelvic uptake, associated with an elevated Tg value just in one patient (26). Thus, the patients underwent further imaging evaluation (CT or magnetic resonance imaging), showing an ovarian lesion, followed by the surgical removal of the mass.…”