TY - JOUR T1 - Follicular Thyroid Carcinoma with Unusual Radioiodine-Refractory Breast Metastasis Mimicking Primary Breast Malignancy JF - Journal of Nuclear Medicine Technology JO - J. Nucl. Med. Technol. SP - 288 LP - 289 DO - 10.2967/jnmt.120.259259 VL - 49 IS - 3 AU - Tarun Kumar Jain AU - Venkata Subramanian Krishnaraju AU - Bhagwant Rai Mittal AU - Ashwani Sood AU - Rajender Kumar AU - Rashi Garg AU - Sunil Kumar Y1 - 2021/09/01 UR - http://tech.snmjournals.org/content/49/3/288.abstract N2 - The breast is an unusual site for metastasis from malignant tumors, although it may be the first manifestation of an extramammary primary malignancy typically arising in the lung, skin (melanoma), ovary, or lymph nodes (lymphoma). Breast metastasis from thyroid carcinoma is extremely rare and may take years to develop, as differentiated thyroid carcinoma is usually indolent and slow-growing and metastasizes to the lymph nodes, lungs, and bones. Here, we present the case of a middle-aged woman (after subtotal thyroidectomy for multinodular goiter 24 y previously) showing discordant 18F-FDG and iodine avidity in proven metastatic disease involving the lymph nodes, bones, spleen, and breast on whole-body 131I and 18F-FDG scans due to tumor heterogeneity. ER -