Incidental finding of a dermoid cyst in a whole-body iodine scan: importance of using [131I]SPECT/CT in the differentiated thyroid carcinoma

A 33-year-old female with a history of total thyroidectomy for papillary thyroid carcinoma was referred to the nuclear medicine department for ablative radioiodine therapy. Post ablation scan showed an area of intense iodine uptake on the left side of the pelvic region, corresponding to the large well-defined heterogeneous mass in the left ovary in the SPECT/CT images. The radiologic features of this lesion were compatible with a dermoid cyst, previously unrecognized. Eventually, the lesion was laparoscopically removed, and a typical dermoid cyst was confirmed through histopathologic assessment.