Abstract. Lamy O, Jenzer-Closuit A, Burckhardt P (University Hospital, Lausanne, Switzerland). Hypercalcaemia of malignancy: an undiagnosed and undertreated disease. J Intern Med 2001; 250: 73±79.Background. Hypercalcaemia of malignancy, a relatively frequent phenomenon, seems to be insuf®-ciently recognized and treated. Its symptoms are not speci®c, but they affect the quality of life. Methods. A prospective study to analyse the in¯u-ence of symptoms caused by hypercalcaemia on the decision of the admitting physician, the motivation for treatment, and the effect of the treatment on the given symptoms in hospitalized patients with oncologic disease in progression, where confounding causes of similar symptoms such as cerebral metastasis, radiotherapy, treatment with opioids, etc., were excluded. Results. A total of 71 patients, mean age 65 + 11 years, ful®lled the strict inclusion criteria. About 42% were hospitalized because of symptoms caused by hypercalcaemia, but none of the medical reports mentioned hypercalcaemia as reason for hospital-