%0 Journal Article %A Rohit Ranade %A Swati Rachh %A Sandip Basu %T Late Manifestation of Struma Peritonei and Widespread Functioning Lesions in the Setting of Struma Ovarii Simulating Highly Differentiated Follicular Carcinoma %D 2015 %R 10.2967/jnmt.114.149294 %J Journal of Nuclear Medicine Technology %P 231-233 %V 43 %N 3 %X Malignant transformation of struma ovarii is a rare event observed in about 5% of cases. We present here an unusual case that closely simulated highly differentiated follicular carcinoma, an entity with a relatively similar appearance to malignant struma ovarii. In our case, peritoneal and systemic dissemination occurred 18 y after excision of struma ovarii, which had been reported as histopathologically benign. There were 3 noteworthy features in the case: the highly functioning nature of the lesions (evidenced by a low level of thyroid-stimulating hormone even without thyroxine suppression); the low to minimal 18F-FDG avidity of the foci, which reiterates the well-differentiated nature of these lesions, as expected in highly differentiated follicular carcinoma; and prominent involvement of rare sites such as spleen and liver, in addition to usual sites such as lungs, peritoneum, and bilateral adnexae. %U https://tech.snmjournals.org/content/jnmt/43/3/231.full.pdf