Acquired central hypothyroidism is caused by a defect in the hypothalamic-pituitary-thyroid axis, leading to decreased production of thyroid hormones. The most common cause is pituitary dysfunction, which can be caused by infiltrative diseases such as hemochromatosis and sarcoidosis, or by a tumor or stroke. Other causes include medications, head trauma, radiation therapy, and surgical removal of the pituitary gland.
The diagnosis of acquired central hypothyroidism is based on clinical signs and symptoms, as well as laboratory tests such as thyroid-stimulating hormone (TSH) and free thyroxine (FT4). A high TSH and low FT4 are diagnostic of hypothyroidism.
Differential diagnosis of acquired central hypothyroidism includes other causes of hypothyroidism such as primary hypothyroidism, secondary hypothyroidism due to hypothalamic dysfunction, and subclinical hypothyroidism.
Treatment of acquired central hypothyroidism involves thyroid hormone replacement therapy, usually with levothyroxine. Patient’s dose should be titrated to normalize TSH and FT4 levels.
The prognosis for acquired central hypothyroidism is generally good with appropriate treatment. Long-term follow-up is important to ensure that the patient’s thyroid hormone levels are maintained in the normal range.