[Paraneoplastic hypercalcemia in primary bronchial cancer].

Paraneoplastic hypercalcemia is frequently observed in squamous cell carcinoma of the bronchus. Clinically, apart from the general symptoms which are always very marked, neurological signs are the most common. This hypercalcemia, accompanied by hypophosphatemia, is of sudden onset and immediately very high. Metabolic alkalosis, with hypokalemia and hypochloremia, differentiates it from true hyperparathyroidism. Symptomatic treatment is only transiently effective. However, the obvious effect of mitramycin may be useful before surgical operation, which alone produces a lasting normalisation of serum calcium. Inappropriate secretion of a parathormone substance by the tumour may be demonstrated by radio-immunoassay, and this explains a large number of cases of hypercalcemia but this does not exclude other possible factors in the etiology. Finally, hypercalcemia originally attributed to bony lysis, may be explained in some cases by a paraneoplastic process.