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A 55-year-old man presented for a regular follow-up to your office 6 months ago ago at which time a palpable nodule of 1.7 cm was noted in the left thyroid lobe. A TSH level was normal. Subsequently, he underwent an FNAC which revealed Papillary Carcinoma of thyroid. Staging work-up revealed no evidence of distant metastases and a neck CT scan did not reveal any lymphadenopathy. He underwent total thyroidectomy combined with RAIU therapy and was started on levothyroxine. The patient arrives for follow up visit at 6 months. His TSH level at 6 month is less than 0.1. He denies any symptoms such as palpitations or chest pain or heat intolerance. His weight is unchanged. Most appropriate next step in management?
a) Reduce levothyroxine dose
b) Discontinue levothyroxine
c) Obtain serum thyroglobulin level
d) Obtain anti-thyroglobulin antibodies and serum thyroglobulin levels.
e) Radio-iodine scan

Answer is D. to check out if there is some thyroid tissue left . Thyroglobulin is a protein from inside of thyroid folicules. If the tests will be negative then there is too much levothyroxine.

YOU ARE RIGHT GRIGOLIA

OLD QUESTION FOR ARCHER

Ans. D

Both thyroglobulin and thryroglobulin antibodies must be obtained. Serum thyroglobulin level must be monitored every 6 months to detect persistent or recurrent disease after the surgery. About 25% of patients tend to have antithyroglobulin antibodies even after complete surgical removal of thyroid gland. These antibodies can interfere with serum thyroglobulin assay and can lead to falsely low serum thyroglobulin level. Hence, the antibodies must be measured along with serum thyroglobulin for accurate interpretation of the assay.