Autoimmune polyglandular syndromes (APS) are constellations of symptoms and signs of multiple glandular insufficiencies. We report a rare case of type III APS in a female patient. A 51-year-old woman was treated with radiotherapy because of thymus hyperplasia when she was two years old; she was diagnosed with celiac disease and autoimmune hypothyroidism at 41 years old and with sicca syndrome and myasthenia gravis seronegative a few years later. Our patient demonstrates a previous constellation of diseases of APS, which may be a random association but may also indicate a common immunological and genetic disturbance. The APS is an expression of a system impairment of immune tolerance to autoreactive clones, and this is necessary because the phenomena can become aggressive and expressed clinically. We suppose that the development of thymic hyperplasia or its radiotherapy in childhood may have compromise the patient's immune system
