Endocrine Hormone-Secreting Tumors extend the endocrine emergency map beyond the glands themselves. Insulinoma (beta-cell tumor): episodic fasting hypoglycemia. Boards test Whipple's triad: hypoglycemic symptoms + documented low glucose (<50 mg/dL during episode) + relief with glucose administration. Nursing: small frequent meals, avoid prolonged fasting. Glucagonoma: hyperglycemia + necrolytic migratory erythema (pathognomonic skin rash) + anemia + weight loss. Gastrinoma (Zollinger-Ellison syndrome): excess gastrin → extreme gastric acid → refractory peptic ulcers, multiple ulcer sites, high-volume diarrhea. High-dose PPI therapy; identify endocrine etiology when standard PUD treatment fails. Ectopic ACTH: small cell lung cancer, carcinoid tumors, and thymomas secrete ACTH → bilateral adrenal stimulation → Cushing features without a pituitary source. Low-dose dexamethasone suppression test fails to suppress; the cause is the primary tumor, not the pituitary. MEN syndromes (Multiple Endocrine Neoplasia): MEN1 = pituitary + parathyroid + pancreatic tumors; MEN2a = medullary thyroid cancer + pheochromocytoma + hyperparathyroidism. Family history of multiple endocrine tumors signals genetic testing referral.