Mediastinal ectopic benign colloid goitre detected using iodine-131 whole body scintigraphy and single-photon emission computed tomography-computed tomography.

Ectopic thyroid tissue primarily occurs along the course of the embryologic migration of the thyroid gland. Mediastinal thyroid may be differentiated into primary and secondary form. Primary mediastinal goiters are quite rare, occurring in <1% of all goiters. We present findings of 29-year-old female, case of papillary carcinoma of the thyroid who underwent iodine-131 whole body scintigraphy after total thyroidectomy showed a primary mediastinal mass lesion along with residual thyroid. She underwent mediastinal mass excision through sternotomy and biopsy confirmed as ectopic nodular colloid goiter with no malignancy.