Metastatic follicular thyroid carcinoma to the thymus in a 35-year-old woman.
Clinically detectable metastatic follicular thyroid carcinoma to the thymus is very rare in the literature and sometimes confused with false positive uptake of Iodine(131) (I(131)) in the normal thymus or hilar lymph node. The authors report a 35-year-old woman with metastatic follicular carcinoma to the thymus. She underwent total thyroidectomy and I(131) ablation with 200 mCi. Six months later, a follow-up I(131) whole body scan showed continued radioactive iodine uptake in the retrosternal area and the serum thyroglobulin level remained continuously elevated with levothyroxine suppression therapy (22.3 and 36.4 ng/ml, 6 and 10 months after total thyroidectomy, respectively). CT scan of the chest revealed several aggregated cystic lesions in the retrosternal mediastinum, suspected to represent mediastinal metastasis. The surgically resected retrosternal mass was confirmed as a metastatic follicular carcinoma to the thymus. After surgical excision, the serum thyroglobulin level was below 1.0 ng/ml and I(131) whole body scan showed no radioactive iodine uptake in the mediastinum. The patient showed no evidence of recurrence after excision of thymic metastasis during one year of 0.2 mg levothyroxine suppression therapy. We report a case of metastatic follicular thyroid carcinoma to the thymus without bone or pulmonary involvement.
Nam
Moon Suk
MS
Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea. namms@inha.ac.kr
Chu
Young Chae
YC
Choe
Won Sick
WS
Kim
Sei Joong
SJ
Hong
Seong Bin
SB
Kim
Yoe Joo
YJ
Kim
Yong Seong
YS
D018263:Adenocarcinoma, Follicular / Q000556:secondary*; D000328:Adult; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D013953:Thymus Neoplasms / Q000556:secondary*; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D014055:Tomography, Emission-Computed
D007457:Iodine Radioisotopes