Abstract： To the Editor: We reported 2 cases of ectopic thyroid gland (ETG) masquerading as pituitary adenoma (PA).The first case was a 15-year-old boy with growth, and mental retardation whose height was 121 cm and weight was 44 kg on admission.Bone age development index was 40, while bone age showed 6-10 years old.Magnetic resonance imaging (MRI) revealed pituitary hyperplasia [Figure la].Thyroid ultrasonography did not found thyroid on the anterior aspect of the neck and thenormal position of thyroid gland.