A 64 year old man with a 50 pack year smoking history presents with weight loss, cough, constipation, and confusion. Chest imaging reveals a hilar mass. Laboratory studies show calcium 13.8 mg per dL, suppressed parathyroid hormone, and normal 25 hydroxyvitamin D. Which of the following is the most likely mechanism of his hypercalcemia?

  1. A)Tumor secretion of PTH related peptideGABARITO
  2. B)Primary hyperparathyroidism from MEN syndrome
  3. C)Destruction of parathyroid glands by metastases
  4. D)Autoantibodies activating the calcium sensing receptor
  5. E)Excess calcitonin secretion by the tumor

Explicação

Squamous cell carcinoma of the lung classically causes paraneoplastic hypercalcemia by secreting PTH related peptide. The elevated calcium with suppressed native PTH and a hilar smoking related lung mass strongly support this mechanism. Ver explicação completa e trilha adaptativa →

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