Lingual Thyroid: A Case Report

Abstract

Hypothyroidism is a common disease, usually managed in primary health care. In its initial study, it is important to consider the hypothesis of lingual thyroid, even though it is a rare anomaly.
Female patient, 48 years old, recently transferred from another health unit, presents for her first doctor appointment. When asked, mentions that in her early adolescence, after a thyroid ultrasound, she was informed that “born without thyroid” (sic), being medicated with levothyroxine 0.175 mg once a day since then. As a relevant family history, mentions that her mother and niece have thyroid pathology. On physical examination, there was no thyroid tissue in its normal pre-tracheal location.
The thyroid ultrasound performed revealed the absence of thyroid in its usual topography. The analytical study of thyroid function revealed no changes. Thyroid scintigraphy was then requested, which demonstrated a focus of radiopharmaceutical uptake in the topography of the mouth, compatible with functioning thyroid tissue in an ectopic location. The patient was referred to a general surgery consultation and proposed for ectopic thyroid resection surgery, which was uneventful.
In this case, the investigation triggered by the suspicion of a rare entity, even years after the initial diagnosis of hypothyroidism was central, showing the privileged position of the family doctor in the study and guidance of their patients.