Given the question: Information:  - The hypothalamus (from Greek , "under" and , thalamus) is a portion of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland (hypophysis).  - Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, is an autoimmune disease in which the thyroid gland is gradually destroyed. Early on there may be no symptoms. Over time the thyroid may enlarge forming a painless goitre. Some people eventually develop hypothyroidism with its accompanying weight gain, feeling tired, constipation, depression, and general pains. After many years the thyroid typically shrinks in size. Potential complications include thyroid lymphoma. Hashimoto's thyroiditis is thought to be due to a combination of genetic and environmental factors. Risk factors include a family history of the condition and having another autoimmune disease. Diagnosis is confirmed with blood tests for TSH, T4, and antithyroid antibodies. Other conditions that can produce similar symptoms include Graves disease and nontoxic nodular goiter. Hashimoto's thyroiditis, regardless of whether or not hypothyroidism is present, can be treated with levothyroxine. If hypothyroidism is not present some may recommend no treatment while others may treat to try to reduce the size of the goitre. Those affected should avoid eating large amounts of iodine; however, sufficient iodine is required especially during pregnancy. Surgery is rarely required to treat the goitre. Hashimoto's thyroiditis affects about 5% of the population at some point in their life. It typically begins between the ages of 30 and 50 and is much more common in women than men. Rates of disease appear to be increasing. It was first described by the Japanese physician Hakaru Hashimoto in 1912. In 1957 it was recognized as an autoimmune disorder.  - Pickardt syndrome ( also Pickardt 's syndrome or Pickardt -- Fahlbusch syndrome ) denotes a rare form of tertiary hypothyroidism that is caused by interruption of the portal veins connecting hypothalamus and pituitary . It was characterized in 1972 and 1973 .  - The endocrine system is the collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards distant target organs. The phenomenon of biochemical processes' serving to regulate distant tissues by means of secretions directly into the circulatory system is called endocrine signaling. The major endocrine glands include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, and adrenal glands. The endocrine system is in contrast to the exocrine system, which secretes its hormones to the outside of the body using ducts. The endocrine system is an information signal system like the nervous system, yet its effects and mechanism are classifiably different. The endocrine system's effects are slow to initiate, and prolonged in their response, lasting from a few hours up to weeks. The nervous system sends information very quickly, and responses are generally short lived. In vertebrates, the hypothalamus is the neural control center for all endocrine systems. The field of study dealing with the endocrine system and its disorders is endocrinology, a branch of internal medicine. Special features of endocrine glands are, in general, their ductless nature, their vascularity, and commonly the presence of intracellular vacuoles or granules that store their hormones. In contrast, exocrine glands, such as salivary glands, sweat glands, and glands within the gastrointestinal tract, tend to be much less vascular and have ducts or a hollow lumen.  - Hypothyroidism, also called underactive thyroid or low thyroid, is a common disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as poor ability to tolerate cold, a feeling of tiredness, constipation, depression, and weight gain. Occasionally there may be swelling of the front part of the neck due to goitre. Untreated hypothyroidism during pregnancy can lead to delays in growth and intellectual development in the baby, which is called cretinism. Worldwide, too little iodine in the diet is the most common cause of hypothyroidism. In countries with enough iodine in the diet, the most common cause of hypothyroidism is the autoimmune condition Hashimoto's thyroiditis. Less common causes include: previous treatment with radioactive iodine, injury to the hypothalamus or the anterior pituitary gland, certain medications, a lack of a functioning thyroid at birth, or previous thyroid surgery. The diagnosis of hypothyroidism, when suspected, can be confirmed with blood tests measuring thyroid-stimulating hormone (TSH) and thyroxine levels. Prevention at the population level has been with the universal salt iodization. Hypothyroidism can be treated with levothyroxine. The dose is adjusted according to symptoms and normalization of the thyroxine and TSH levels. Thyroid medication is safe in pregnancy. While a certain amount of dietary iodine is important, excessive amounts can worsen certain types of hypothyroidism. Worldwide about one billion people are estimated to be iodine deficient; however, it is unknown how often this results in hypothyroidism. In the United States, hypothyroidism occurs in 0.30.4% of people. Subclinical hypothyroidism, a milder form of hypothyroidism characterized by normal thyroxine levels and an elevated TSH level, is thought to occur in 4.38.5% of people in the United States. Hypothyroidism is more common in women than men. People over the age of 60 are more commonly affected. Dogs are also known to develop...    After reading the paragraphs above, we are interested in knowing the entity with which 'pickardt syndrome' exhibits the relationship of 'medical specialty'. Find the answer from the choices below.  Choices: - endocrinology  - surgery
The answer is:
endocrinology