%0 Journal Article %A Tarun Kumar Jain %A Venkata Subramanian Krishnaraju %A Bhagwant Rai Mittal %A Ashwani Sood %A Rajender Kumar %A Rashi Garg %A Sunil Kumar %T Follicular thyroid carcinoma with unusual radioiodine refractory breast metastasis mimicking primary breast malignancy %D 2021 %R 10.2967/jnmt.120.259259 %J Journal of Nuclear Medicine Technology %P jnmt.120.259259 %X Breast is unusual site for metastasis from malignant tumors though may be the first manifestation of extra-mammary malignancy with primary typically arising from lung, melanoma, ovary and lymphoma. Breast metastasis is extremely rare from thyroid carcinoma and may take years to develop as differentiated thyroid carcinoma are usually indolent, slow growing and metastasize to lymph nodes, lungs and bones. Here is a middle-aged woman (post-subtotal thyroidectomy for multi-nodular goitre 24 years ago) showing discordant FDG and iodine avidity in proven metastatic disease involving lymph nodes, bones, spleen and breast on whole-body radioiodine and FDG-PET/CT due to tumor heterogeneity. %U https://tech.snmjournals.org/content/jnmt/early/2021/03/12/jnmt.120.259259.full.pdf