Unusual sites of metastases from differentiated thyroid carcinoma: a case series

During long term follow up period 6-20% patients with differentiated Thyroid carcinoma (DTC) develop distance metastases. Unusual metastasis from DTC is very rare (<1%). The objective of the study is to report three cases of patients with DTC with unusual distant metastases. Metastatic sites from DTC are usually identified by clinical evaluation, performing whole body scans (WBS) with stimulated serum thyroglobulin (Tg) level, Ultrasound, CT scan and histopathology. Among the reported cases, two were female and one was male and the mean age was 65 years. Histopathology report (HPR) of these reported cases were follicular variant papillary carcinoma, papillary carcinoma and follicular carcinoma having metastases in right lobe of liver, roof of the nasal cavity including right ethmoidal sinus and left side of the upper gum respectively. Patient with liver metastases was evaluated at time of diagnosis by ultrasound imaging. The median time interval between the first diagnosis and metastases of the other two cases was 05 years. Metastasis in upper gum was clinically visible lesion. CT scan revealed metastases in the roof of nasal cavity. In WBS findings of these cases only liver metastasis showed iodine avidity. All metastatic sites were confirmed by histopathology. Gum metastasis was excised and other two cases refused to do operation. Tg levels in all cases were >300 ng/ml with absence Tg antibody. Individualized and patient specific management approach in unusual site metastases from DTC seems to be beneficial with the supports of multidisciplinary team. (author)