TREATMENT OF A LINGUAL THYROID

QUESTION–A young 23 years old girl diagnosed to have Functional ectopic lingual thyroid with Overt Hypothyroidism with absence of tracer uptake in the thyroid region on Tc99 scintigraphy in the year 2004. Since she has been on 125mcg Thyroxine replacement. Her TSH was 19uIU/ml in Feb 2013 and on proper dose titration as now TSH reached to 12uiU/ml in May 2013.
She has no dysphagia, dysphonia  or any other problem. Physical examination revealed a solid, pink, spherical mass, covered with intact mucosa, located at the base of the tongue. There was no change in swelling size all these years.
Is it advisable go for surgery or just leave it as she doesn't have any symptoms from lingual thyroid? I would like to know chance of malignancy these type of patients. How to predict malignancy early?  What is the best treatment approach.  Best regards, Dr Sreenivas

RESPONSE— Firstly, a question.  The m

ass is described as a functional ectopic thyroid, but the patient was hypothyroid prior to treatment, and no RAI uptake in the base of the tongue was described. Please comment
I suppose this is a poorly functioning ectopic thyroid, perhaps with minimal thyroid tissue, perhaps partially cystic, perhaps even injured by thyroiditis. It has not grown significantly in several years, even under the pressure of elevated TSH.
I know of no statistics indicating that lingual thyroids have an increased risk of malignancy, especially if TSH is normal. Your patient denies symptom. So it seems sensible to make sure her TSH is adequately suppressed (bottom of the normal range) and follow the size visually. RAI ablation probably would not work, and surgery is not required if the mass is asymptomatic and stable over the years. It might be of interest to monitor TG during follow-up, if a serum level is present.  L De Groot,  MD