Incidental lingual thyroid with subclinical hypothyroidism: case report

Background: Lingual thyroid is a very rare pathological finding and is usually incidentally discovered. It occurs when a defect in embryogenesis gives rise to ectopic thyroid as tongue base mass. Majority of patients are asymptomatic. This clinical case highlights the importance of performing thyroid function tests for all lingual thyroid patients regardless of symptoms or clinical presentation. Case presentation: We present a 25-year-old lady who presented with sub-mental abscess. A CT scan was performed to confirm the diagnosis. The CT scan confirmed submental abcess and incidentally discovered lingual thyroid along with absence of thyroid tissue in its normal pretracheal position. The patient denied any symptoms of hypothyroidism. But subsequent investigations revealed clinical hypothyroidism. She was started on substitutive hormone therapy and remains asymptomatic. Conclusion: Lingual thyroid patients may remain asymptomatic with subclinical hypothyroidism. Hormone therapy needs to be initiated in these patients.