The answer is E.
The correct choice is E, diffusely low uptake. Acute inflammation is occurring during subacute thyroiditis, causing leakage of stored thyroid hormone into the circulation. The thyroid is not metabolically active, and therefore there is low radioactive iodine uptake on scan. This is in distinction to the diffuse increased uptake seen on scan in Graves' disease, choice B. Choice A, a single area of increased uptake, is commonly seen with a "hot" or toxic nodule. Choice C, multiple areas of increased uptake, are found in patients with multinodular goiters. This patient had no nodules noted on exam. Choice D, single area of low uptake, is seen as cold nodules and may be related to a benign nodule or thyroid cancer.
The answer is C.
The correct choice is C, transsphenoidal resection. This patient is presenting with acromegaly, which is typically caused by an adenoma of the anterior pituitary gland. The procedure of choice for this condition is surgical removal. Choice A, somatostatin analogs (such as Octreotide LAR), can be used to treat patients with this condition, and areas associated with a reduction in GH and IGF-I levels in 75% of patients; however, a smaller percentage of patients have tumor regression. This medication is used primarily as an adjunct to surgery if GH hypersecretion remains. Choice B, dopamine agonists (such as cabergoline), have been used to treat patients with acromegaly, but are associated with a normalization of IGF-I in only 30% of patients. Choice D, GH receptor agonists, are not used to treat patients with acromegaly. To the contrary, GH receptor antagonists (such as Pegvisomant) are the newest medications used to treat acromegaly, but are limited in use due to cost and need for daily injections. Choice E, local irradiation therapy, should not be used since reduction in GH levels would not happen for several years after therapy, and therapy is associated with development of hypogonadism and hypothyroidism
The answer is A.
The correct choice is A, high serum TSH, low serum total T4, and high thyroidal peroxidase antibodies. Hashimoto's thyroiditis is the most common cause of primary hypothyroidism and is autoimmune in nature. The serum thyroid hormone levels are low, secondary to the destruction occurring in the thyroid gland. The negative feedback loop causes the pituitary to respond by increasing production and secretion of TSH. Thyroidal peroxidase, thyroglobulin, and TSH receptor blocking autoantibodies can be found in these patients. Choice B, low serum TRH, low serum TSH, and low serum free T3 levels, is seen in patients with secondary hypothyroidism relating to pathology in the hypothalamus. Choice C, normal TSH, normal serum total T4, and normal radioactive iodine uptake, is seen in patients who are euthyroid. Choice D, low serum TSH, high serum total T4, and high thyroid stimulating antibodies, are findings in patients with primary hyperthyroidism (e.g. Graves' disease). Choice E, high serum TSH, high radioactive iodine uptake, and high serum free T3 can be seen in patients with secondary hyperthyroidism, as a result of anterior pituitary pathology.
autoimmune destruction. This is responsible for 80% of cases of primary adrenal insufficiency in the United States. All of the other choices can cause adrenal insufficiency, but they are less common. Tuberculosis, choice A, is a common cause of adrenal insufficiency in other areas of the world, where the infection is more common. Bilateral adrenal hemorrhage, choice B, can occur as a complication of sepsis, heparin use, anti-phospholipid syndrome, and after major trauma or surgery. Lymphoma, choice C, and metastatic carcinoma, choice E, are rare causes of adrenal insufficiency. The answer is D.
The correct choice is D, bone and lung via bloodstream. Follicular thyroid cancer can spread to regional lymph nodes and distant sites via the blood stream. Choice A, intraglandular metastasis, is seen more commonly in papillary thyroid carcinoma, and choice B, local spread into regional vocal cords, occurs in anaplastic thyroid carcinoma. Choice C, distant lymph nodes, and choice E, local extension into the muscle and trachea, are more commonly seen in patients with medullary thyroid cancer.
The answer is A.
The correct choice is A, pituitary adenoma. This patient's clinical presentation is typical in Cushing's syndrome. The most common cause of Cushing's syndrome (other than ingestion of oral steroid medications) is Cushing's disease. This disease is caused by a benign, ACTH secreting pituitary adenoma. Choice B, iatrogenic, refers to the ingestion of prescribed (or non-prescribed) oral corticosteroid medications. This is frequently seen in patients requiring long-term oral steroid medications. This patient does not have this type of history. Choice C, adrenal micronodular hyperplasia, and choice D, adrenocortical adenoma, can cause Cushing's syndrome at less frequent incidence. Choice E, ectopic ACTH syndrome, presents more commonly in males with extremely elevated levels of plasma cortical and ACTH. These patients commonly have a positive history of an ectopic source of the ACTH, such as in small cell carcinoma of the lung.
iodine deficiency. Dietary iodine is required for thyroid hormone production, yet many countries do not have sufficient amounts of dietary iodized salt for their population. Choices A, thyroidectomy, and C, external neck irradiation, can cause hypothyroidism throughout the world, but not as commonly as iodine deficiency. Choices D, pituitary infiltrative tumor, and E, hypothalamic trauma, are rare causes of secondary hypothyroidism. The answer is B.
The correct choice is B, Graves' disease. Graves' disease is an autoimmune disorder, resulting in an increase in synthesis and release of thyroid hormone. It is the most common cause of hyperthyroidism. Choice A, pituitary tumor, and choice C, thyroid carcinoma, are rare causes of hyperthyroidism. Choice D, Hashimoto's thyroiditis, is a common cause of hypothyroidism. Choice E, euthyroid sick syndrome, is a condition of normal thyroid function that occurs after major surgery or an acute illness. This patient is not acutely ill and does have symptoms of true hyperthyroidism.