For each of the following endocrine and neuroendocrine clinical scenarios, select the most appropriate targeted laboratory investigation to confirm the suspected underlying diagnosis.
- A 42-year-old female presenting with episodic facial flushing, chronic watery diarrhea, and a new-onset right-sided heart murmur.24-hour urine 5-hydroxyindoleacetic acid (5-HIAA)
- A 38-year-old male evaluated for recurrent calcium oxalate nephrolithiasis, dyspepsia refractory to proton pump inhibitors, and persistent hypercalcemia.Serum intact parathyroid hormone and gastrin levels
- A 48-year-old female experiencing paroxysmal severe headaches, unexplained diaphoresis, palpitations, and episodic severe hypertension.Plasma fractionated free metanephrines
- A 45-year-old male presenting with progressive proximal muscle weakness, easy bruising, wide violaceous abdominal striae, and unexplained hypokalemia.Overnight 1-mg dexamethasone suppression test
Cevap
The presentations map to diagnostic tests for Carcinoid syndrome (5-HIAA), Multiple Endocrine Neoplasia type 1 (PTH and gastrin), Pheochromocytoma (metanephrines), and Cushing's syndrome (dexamethasone suppression test), respectively.
Each scenario describes a classic presentation of a functional neuroendocrine or endocrine tumor. The foundational principle in working up these conditions is that biochemical confirmation of hormone excess must be established through highly specific and sensitive laboratory testing prior to localizing the tumor with imaging.
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Anahtar Kavram
Selecting the appropriate initial biochemical screening test for suspected endocrine and neuroendocrine tumors based on classic clinical syndromes.