HYPERCALCEMIA IN SMALL-CELL LUNG-CANCER - REPORT OF A CASE ASSOCIATEDWITH PARATHYROID HORMONE-RELATED PROTEIN (PTHRP)

Although hypercalcaemia is frequently associated with malignancy, it i s very rare in small cell lung cancer despite the high incidence of ly tic bone metastases. We report a patient with extensive small cell can cer who presented with hypercalcaemia. Investigations suggested parath yroid hormone (PTH) receptor stimulation, although the serum PTH level was not elevated. PTH related protein (PTHrP) was localised in a biop sy specimen from the tumour. Although hypercalcaemia is rare in small cell lung cancer, when hypercalcaemia does occur, PTHrP may be a causa l factor.