Endocrine Disorders Quiz

A 45-year-old patient presents with visual field defects and elevated intracranial pressure. Imaging reveals a well-circumscribed lesion in the sella turcica extending superiorly. This is most consistent with which morphological feature of pituitary adenomas?

• Infiltration into adjacent bone in 30% of cases

• Compression of the optic chiasm due to suprasellar extension

• Exclusive encapsulation without mass effects

• Hemorrhage leading to apoplexy in all large lesions

Which of the following is the most common cause of hypopituitarism associated with posterior pituitary dysfunction, such as diabetes insipidus?

• Pituitary adenomas

• Hypothalamic lesions

• Sheehan syndrome

• Traumatic brain injury

In Sheehan syndrome, the primary pathogenesis involves which sequence of events?

• Postpartum enlargement of the pituitary followed by hypotensive shock and ischemic necrosis

• Chronic inflammation leading to fibrosis of the anterior lobe

• Metastatic carcinoma causing direct destruction

• Radiation-induced atrophy of the posterior lobe

A patient with acromegaly shows excessive growth hormone secretion after closure of epiphyseal plates. Which of the following is a key pathophysiological feature?

• Direct stimulation of osteoblasts by GH leading to bone elongation

• Activation of insulin-like growth factor-1 (IGF-1) causing soft tissue and bone overgrowth

• Suppression of gonadotropins leading to delayed puberty

• Mutant G-protein eliminating the need for GHRH in all cases

Which complication of acromegaly is directly related to hypersecretion of growth hormone affecting connective tissue and bone?

• Sleep apnea due to soft tissue enlargement

• Uterine fibroids from estrogen imbalance

• Colonic polyps from mucosal hyperplasia

• All of the above

Gigantism differs from acromegaly primarily in that it occurs:

• After puberty with disproportionate bone growth

• Before closure of epiphyseal plates leading to proportionate excessive growth

• Exclusively in males due to testosterone synergy

• With hypopituitarism as a secondary feature

In hyperprolactinemia, which mechanism primarily regulates prolactin secretion under normal conditions?

• Tonic inhibitory control by dopamine via D2 receptors

• Stimulatory control by thyrotropin-releasing hormone (TRH) alone

• Pulsatile release independent of hypothalamic input

• Feedback from estrogen levels in females only

In Cushing's syndrome caused by ACTH-secreting pituitary adenomas, what is the most common underlying lesion?

• Macroadenoma with CRH overproduction

• Microadenoma leading to nodular cortical hyperplasia

• Corticotroph cell hyperplasia secondary to ectopic ACTH

• Adrenal carcinoma with feedback inhibition

Which clinical feature of Cushing's syndrome is due to the catabolic effects of hypercortisolism on collagen and bone?

• Truncal obesity and moon facies

• Thin, fragile skin with easy bruising and osteoporosis

• Hypertension and glucose intolerance

• Hirsutism and menstrual irregularity

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) results in hyponatremia primarily due to:

• Impaired water excretion from continued ADH secretion despite normal plasma volume

• Increased sodium reabsorption in renal tubules

• Hypo-osmolality leading to aquaporin-2 channel suppression

• Volume depletion sensed by baroreceptors