Abstract 745
Case Summary
Purpose: Papillary thyroid carcinoma (PTC) consist 75–85% of all thyroid cancers Among them, occult papillary thyroid carcinoma presented as isolated cervical lymphadenopathy, it may imitate the course of a benign disease, thus delaying diagnosis and proper treatment. We report a case of a 74-year old who presented occult papillary thyroid carcinoma.
Case: A 74-year-old man visited a endocrinology department due to diabetes mellitus, and performing neck dopler ultasonography due to cervical vascular evaluation. Incidentally, 13x11 mm sized mass was noticed on right thyroid robe which look like benign feature and 22x16mm sized mass was noticed on right neck level III which suspicious features for malignancy. Hematologic test was no abnormal value, thyroid scans were performed using Tc-99m and no abnormality was found in other sites. Fine needle aspiration was done, the result of right thyroid was non-diagnostic feature, and Rt. neck level III lymph node was metastatic papillary carcinoma. Total thyroidectomy with right functional neck dissection was performed. Right thyroid mass was nodular hyperplasia, otherwise seven out of twenty – one lymph node was metastatic papillary carcinoma.
Discussion: Enlarged cervical LN can be evaluated with ultrasound, radionuclide scans, CT and/or MRI, but 25% of patients with PTC may have normal thyroid imaging. Ultrasonographic features which supported metastatic papillary carcinoma in cervical LNs are cystic masses with thickened-irregular inner lining. If a suspicious LN was detected, FNA can be performed as a first step. FNA is a useful method for determining of typical diagnostic cytopathologic features of PTC. Proposed treatment for patients diagnosed as PTC with metastasis to cervical LN is total thyroidectomy and appropriate ipsilateral and/ or contralateral modified radical neck dissection.
Conclusions: When a metastatic LN is present but clinical/radiological exams reveal a normal appearing thyroid, the best choice as the first diagnostic step is FNA of LN. Thyroidectomy should be performed for definitive diagnosis and treatment of metastatic PTC. When it is followed up by postoperative radionuclide scan and lifelong suppressive thyroxin, outcome is usually good.