Endocrine Abstracts

Introduction: Abnormalities in the development and migration of the thyroid gland are known to produce ectopic thyroid tissue, usually in the midline between the tongue base and the diaphragm. Hashimoto’s thyroiditis involving ectopic thyroid tissue is particularly unusual. Herein we report a case of Hashimoto’s thyroiditis developing in a midline thyroid cervical mass.

Observation: A 55-year-old man was referred for hypothyroidism. His physical and psychomotor development was completely normal. His thyroid gland was not palpable in its normal pretracheal position. Elevated thyroid-stimulating hormone levels (TSH=19.8 μIU/ml, range 0.35–4.5) with low free serum thyroxine (0.64 ng/ml) value were found. In addition, high titers of antiperoxydase antibodies (295.8 IU/ml) were detected. The neck ultrasound revealed a left lobar hypoplasia and a midline cervical mass representing aberrant thyroid tissue due to migration defects. A Tc-99 m pertechnetate marked isotope showed accumulation at the left thyroid lobe and at the midline cervical mass with no uptake at the right thyroid lobe.

Conclusion: Ectopic thyroid tissue itself is not known to demonstrate a predilection for Hashimoto’s thyroiditis. Despite its rarity, the presence of ectopic thyroid should be considered in the differential diagnosis of all tongue, neck and trachea masses. The ectopic tissue may be functional and affected by the same pathological processes as the thyroid gland.