We present a case of 11-year old boy with Type 1 Autoimmune Polyglandular Syndrome and thyrotropin secreting pituitary adenoma, which was diagnosed by elevated TSH and thyroid hormones levels and MRI signs of pituitary tumor and without clinical symptoms of hyperthyroidism. He underwent partial resection of the tumor via transnasal approach and subsequent radiation therapy. Consequently 1 year after XRT patient developed growth hormone deficiency, 3.5 years later patient became euthyroid, and 5.5 years after treatment - hypothyroid. This is the first described case of coexistence of this 2 rare endocrine diseases in the same patient.