A case of Schmidt syndrome accompanied by a pituitary adenoma

Schmidt syndrome consists of adrenal insufficiency and Hashimoto's thyroiditis, which are probably caused by an autoimmune process. We encountered a patient who manifested severe generalized fatigue due to Schmidt syndrome recurrently. The endocrinological examination tests on the patient showed that the increase in thyroid stimulating hormone (TSH) and ACTH concentrations were not remarkable, despite hypo-function of the peripheral glands. Subsequent cranial magnetic resonance imaging (MRI) exhibited the existence of a pituitary tumor. The pathological findings on the resected tumor and endocrinological stimulation tests proved that the tumor was a FSH-producing adenoma. Although involvement of the pituitary region in Schmidt syndrome on rare occasions presents as hypophysitis, no pituitary adenoma has previously been reported in association with this syndrome. We present a patient with Schmidt syndrome and an accompanying FSH-producing pituitary adenoma. The coexistence of these disorders suggests that the functioning pituitary tumor might be considered as a pituitary lesion in Schmidt syndrome.