A patient with a large retroperitoneal solitary fibrous tumor presents with recurrent severe hypoglycemia. Laboratory studies during an episode show suppressed insulin and C-peptide levels. Which mediator is most likely responsible for this paraneoplastic syndrome?

An infant presents in shock with vomiting, hyponatremia, and hyperkalemia. Physical examination reveals ambiguous genitalia and diffuse hyperpigmentation. Following fluid resuscitation, which intervention is the most critical next step in management?

A pregnant patient with a known gain-of-function mutation in the NR3C2 gene (coding for the mineralocorticoid receptor) experiences a significant and dangerous worsening of her hypertension during the third trimester. This exacerbation is primarily mediated by which endogenous substance?

A patient presents with treatment-resistant hypertension, hypokalemia, and metabolic alkalosis. Endocrine evaluation surprisingly reveals suppressed plasma renin activity and a very low plasma aldosterone concentration. Which of the following agents would be the most specific and effective long-term treatment?

A patient with chronic fatigue and postural dizziness is being evaluated. Which of the following clinical findings would most specifically suggest primary adrenal insufficiency over a pituitary etiology?

A patient with Addison's disease on maintenance hydrocortisone presents with persistent postural hypotension despite adequate glucocorticoid replacement. Laboratory results show persistent hyponatremia. What is the most appropriate medication to add?

A 29-year-old patient is diagnosed with an extra-adrenal, norepinephrine-secreting paraganglioma located in the organ of Zuckerkandl. Genetic testing is performed as part of the workup to assess syndromic association and long-term prognosis. The presence of a germline mutation in which of the following genes would confer the highest risk for future metastatic disease?

A biopsy of the thyroid nodule from the patient is performed. Histopathological examination reveals nests of polygonal cells separated by a fibrovascular stroma. Special staining is positive for calcitonin and carcinoembryonic antigen (CEA). What is the characteristic microscopic finding associated with this tumor?

A patient is diagnosed with bilateral pheochromocytomas. Further evaluation reveals medullary thyroid carcinoma. A germline mutation in which of the following genes is most likely responsible for this patient's clinical presentation?