A 62-year-old woman presents to the clinic for a routine health maintenance examination. She feels well and reports no bone pain, abdominal pain, or urinary symptoms. Her medical history is unremarkable, and she takes no medications. Vital signs are within normal limits.
A comprehensive metabolic panel and subsequent testing reveal the following laboratory results:
| Test | Result | Reference Range |
|---|---|---|
| Calcium, total | 11.2 mg/dL | 8.4-10.2 mg/dL |
| Phosphorus | 2.1 mg/dL | 2.7-4.5 mg/dL |
| Albumin | 4.0 g/dL | 3.5-5.0 g/dL |
| Creatinine | 0.8 mg/dL | 0.6-1.1 mg/dL |
| Intact parathyroid hormone | 105 pg/mL | 10-65 pg/mL |
Which of the following is the most likely diagnosis?
- Primary hyperparathyroidismCevap
- BSecondary hyperparathyroidism
- CHumoral hypercalcemia of malignancy
- DVitamin D toxicity
- EPseudohypercalcemia
Cevap
Primary hyperparathyroidism is the correct diagnosis.
The correct answer accurately synthesizes the laboratory data. Primary hyperparathyroidism is characterized by autonomous overproduction of PTH. This excess PTH acts on the bones (increasing calcium and phosphorus release) and the kidneys (increasing calcium reabsorption and phosphorus excretion). This directly results in the classic laboratory pattern seen here: hypercalcemia, hypophosphatemia, and an elevated intact PTH.
Adım Adım Çözüm
Anahtar Kavram
The classic laboratory profile of primary hyperparathyroidism is hypercalcemia, hypophosphatemia, and an elevated or inappropriately normal intact parathyroid hormone (PTH) level.