Large mass on base of tongue

Making the diagnosis

In addition to history and physical exam, diagnosis of lingual thyroid can be confirmed with a radioactive iodine uptake test or a technetium scan. Biopsy is rarely necessary.

Treatment

Lifelong thyroid suppression therapy is warranted for all patients with lingual thyroid⁹ (strength of recommendation [SOR]: C). In asymptomatic patients this prevents further growth of the lingual thyroid, which often occurs during times of stress such as illness, pregnancy, or puberty.¹⁰ In symptomatic patients, thyroid suppression may lead to glandular atrophy and resolution of symptoms.⁹ Regression in lingual thyroid size is a very slow process. Surgery is reserved for refractory cases and patients with airway obstruction or bleeding.


All patients with lingual thyroid require lifelong thyroid suppression therapy. Our patient’s thyroid-stimulating hormone was significantly elevated at 9.8 mcIU/mL (normal, 0.34-5.60 mcIU/mL) and technetium scanning showed that the lingual thyroid was her only functioning thyroid tissue. It is likely that pregnancy-related stress and increased demand for thyroid hormone caused excessive thyrotropin production. Her lingual thyroid was unable to produce the increased thyroid hormone needed, which resulted in glandular hypertrophy and obstructive symptoms.

Our patient. After we consulted Endocrinology, we started our patient on levothyroxine 125 mcg/d. Six months later, the mass had shrunk in size and her symptoms had improved. We continue to manage her thyroid suppression and monitor her lingual thyroid size twice a year.

CORRESPONDENCE
Jeremy T. Reed, MD, MPH & TM, Department of Otolaryngology, Carl R. Darnall Army Medical Center, Fort Hood, TX 76544; jeremy.t.reed8.mil@mail.mil

Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality 
patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series