A 19-year-old man with a marfanoid body habitus presents with a thyroid nodule. Physical examination reveals mucosal neuromas on the lips and tongue. Vital signs: BP 128/82, HR 88, RR 16, Temp 37°C, SpO2 98%. Serum calcitonin is markedly elevated at 450 pg/mL (normal <10). Thyroid ultrasound confirms a 2-cm right lobe nodule. He denies headaches, palpitations, or abdominal pain. He takes no medications. Which additional malignancy carries the highest risk in this patient?

1. A)Insulinoma
2. B)Prolactinoma
3. C)Parathyroid adenoma
4. D)Adrenal cortical adenoma
5. E)PheochromocytomaGABARITO