Endocrine Abstracts

Introduction

Ectopic thyroid gland (ETG) is a rare developmental disorder, and when occurs in the midline of the neck, it mimics the clinical presentation of thyroglossal duct cyst (TGDC). inadvertent surgical removal of ETG simulating TGDC has been reported in the literature in spite of the modern diagnostic methods for this pathology.^{1, 2}. We report a case of a 27-year-old female with Hashimoto’s thyroiditis of ectopic thyroid in whom a preliminary clinical diagnosis of thyroglossal duct cyst was made clinically and planned for surgery.

Case Report

A 27-year-old female was referred to for evaluation of an anterior upper neck mass that had been present since the age of 6 years without significant change in size. There was no complaint of pain, dyspnea, dysphagia, or voice change and no history of radiation exposure or familial thyroid disease. Patient was evaluated earlier and provisionally diagnosed to have thyroglossal duct cyst and planned for surgery. Preoperative investigation revealed hypothyroidism, so she was referred to our department for the management of hypothyroidism prior to excision. Physical examination showed a palpable rounded smooth mass (3 × 3 cm in size) of rubber-like consistency, that moved upwards on swallowing. It was non-tender, mobile, not attached to overlying skin and skin over the mass was normal. Serologic testing revealed normal FT4 and FT3 of 4.81 pmoL/l, and elevated TSH level of 9.56 mIU/l. Thyroid peroxidase antibodies was strongly positive of 1299 IU/ml. Ultrasonography of the neck revealed a solid soft-tissue mass with diffuse heterogeneous echotexture corresponding to the palpable lesion. The thyroid gland was not visualized in the normal thyroid position. A 99mTc Pertechnetate SPECT/CT Scan showed a single focus of radiotracer uptake anteriorly n the submental region at the site of the palpable mass (Fig 2). There was no evidence of other functioning thyroid tissue in the lower neck region or in other ectopic position. The diagnosis of midline neck ectopic thyroid with subclinical hypothyroidism and Hashimoto’s thyroiditis was made. Replacement with L-thyroxine 50 mcg/day was started and no surgery was performed. On follow-up, patient is doing well, her TSH was 4.3 miU/ml with slight reduction in the size of the ectopic thyroid.