Unusual case of isolated parasellar metastasis from carcinoma of thyroid.

A 48-year-old male patient of papillary carcinoma of thyroid, who had received 3.145 GBq of radioiodine ((131)I) 6 months earlier, presented with recurrent headaches and progressively worsening double vision for 2 weeks. Iodine avid and low metabolic parasellar mass was seen on (131)I SPECT/CT and (18)F-FDG PET/CT, respectively. In view of no bony erosion, meningioma or schwannoma rather than metastasis was considered as first differential diagnosis. However, final histopathology after its partial excision revealed metastasis from thyroid cancer. This case highlights the importance of radioiodine scan to detect a rare occurrence of parasellar metastasis from thyroid cancer.