Sputum cytology: a valuable addition to the investigation of hypercalcemia.

In this paper we report two patients with asymptomatic hypercalcemia, one with primary and the other with ectopic hyperparathyroidism, in whom cytologic examination of the sputum led to the diagnosis of carcinoma of the lung despite the presence of normal chest roentgenograms. Sputum cytology is a simple, inexpensive and accurate test which should be included in the diagnostic regimen for hypercalcemia.