Coexisting kappa light chain multiple myeloma and primary hyperparathyroidism

The authors report the case of an 82 year old woman hospitalized for hypercalcemia associated with low serum phosphate. Multiple myeloma was first diagnosed. However, despite chemotherapy, hypercalcemia persisted and she was subsequently diagnosed as primary hyperparathyroidism; eucalcemic state was then obtained after parathyroidectomy. Fifteen similar cases are reported in the literature and the mechanisms and implications of such an association are discussed.