Lingual Thyroid with Subclinical Hypothyroidism in a Young F
A 27-year-old female presented to the outpatient department with a history of foreign body sensation in the throat with mild dysphagia for 3 weeks. There was no significant medical or surgical history in the past. Throat examination revealed a well-defined nodule in the midline at the base of the tongue with intact smooth mucosa. The thyroid gland could not be appreciated on neck palpation. Chest X-ray was normal. Ultrasonography (USG) neck revealed the absence of a thyroid gland in its orthotopic location. No enlarged cervical lymph nodes were seen. A computed tomography (CT) scan showed a well-defined relatively hyperdense homogeneous enhancing nodule measuring 24×24×22 mm in the midline at the base of the tongue without calcification. No thyroid gland was seen in the orthotopic location. Thyroid function tests showed normal FT3: 3.3 pg/mL (reference value 1.2–4.1 pg/mL), normal FT4: 13.1 pg/mL (reference value 8.9–17.1pg/mL), and slightly elevated TSH: 5.7 mIU/mL (reference value 0.3–4.5 mIU/mL). Fine-needle aspiration cytology (FNAC) from the nodule at the base of the tongue showed a cluster of benign-looking thyroid epithelial cells in the background of RBCs. Thyroid scintigraphy with technetium (Tc-99 m) showed uptake of the radiotracer at the region of the base of the tongue. No uptake was seen in the normal thyroid gland location.

Based on the clinical examination, thyroid function test report, USG, and CT findings, a definitive diagnosis of lingual thyroid with subclinical hypothyroidism were made, and the patient was planned for conservative pharmacological management with levothyroxine supplement. Symptoms gradually resolved by 2 months. The patient is now on a regular follow-up.