USMLE (United States Medical Licensing Examination) Step 1 Practice Exam

Pituitary apoplexy is an acute condition that occurs when there is bleeding into a pituitary adenoma, causing sudden onset of headache, visual disturbances, and loss of pituitary function (hypopituitarism). This condition is different from the other choices - Estrogen effects on TBG and thyroid hormones refers to hormonal changes seen during pregnancy or estrogen therapy, which can lead to increased levels of thyroid hormones and thyroid binding globulin (TBG). This does not involve any bleeding into a preexisting adenoma. - Hashimoto thyroiditis is an autoimmune disease that causes inflammation of the thyroid gland, leading to hypothyroidism. This condition does not involve any adenomas or bleeding. - Subacute granulomatous thyroiditis, also known as de Quervain's thyroiditis, is a self-limiting inflammatory condition of the thyroid gland. While it can cause temporary hyperthyroidism and hypothyroidism, it does not involve any adenomas or bleeding.