Ectopic production of parathyroid hormone by small cell lung cancer in a patient with hypercalcemia.

摘要: Severe hypercalcemia (serum calcium, 4.37–4.84 nmol/L) was found in a 70-yr-old man who had small cell carcinoma of the lung with multiple metastases. The plasma immunoreactive PTH concentration markedly elevated, as measured three different assays [N-terminal PTH, 4,650 ng/L (normal, 230–630); midregion 13,850 180-560); C-terminal 9,900 < 1,300)], but at autopsy parathyroid glands were histologically normal. liver metastasis 503.5 ng/g wet wt (normal liver, <4.2–5.9), and tumor extract eluted nearly same position synthetic human PTH-(1–84) on gel filtration chromatography. Northern blot analysis revealed mRNA single band 0.9 kilobase. These results indicate that ectopic production by cancer cause this patient.