Objective: To describe a case of isolated adrenocorticotropic hormone (ACTH) deficiency associated with thyroid autoimmunity, subclinical hypothyroidism, and transient hyperprolactinemia.
Methods: We present a detailed case report, including results of laboratory studies and magnetic resonance imaging, and discuss potential contributing factors in this setting.
Results: In a 23-year-old woman with isolated ACTH deficiency accompanied by thyroid autoimmunity (Hashimoto's thyroiditis), subclinical primary hypothyroidism, and hyperprolactinemia, magnetic resonance imaging of the pituitary showed normal findings but dynamic stimulation testing of the pituitary gland indicated an isolated ACTH deficiency with intact growth hormone and gonadotropin secretory reserves. The cortisol response to the short ACTH stimulation test was subnormal. Therapy with prednisolone (5 mg/day) and levothyroxine (100 microg/day) was initiated. Results of thyroid function tests were normalized after 1 month, the prolactin level decreased to normal after 1 year, and titers of thyroid autoantibodies decreased substantially after 1.5 years of treatment.
Conclusion: The correction of the related glucocorticoid deficiency resulted in resolution of the hyperprolactinemia and a decrease in titers of thyroid autoantibodies.