Intractable hypercalcemia due to a metastatic carcinoid secreting parathyroid hormone-related peptide and interleukin-6: response to octreotide.

We describe a patient with a malignant carcinoid tumor who presented with severe, intractable hypercalcemia that would not respond to conventional therapy with fluids and pamidronate. His plasma concentrations of parathyroid-hormone-related peptide (PTHrP) and interleukin-6 (IL-6) were elevated. The patient was treated with subcutaneous injections of octreotide with a good response, resulting in normocalcemia. Plasma PTHrP and IL-6 fell with the octreotide but remained elevated above the upper limit of normal. We conclude that although rare, hypercalcemia may be associated with carcinoid tumors and may be mediated through the secretion of cytokines and or PTHrP. Treatment with octreotide may be effective in treating hypercalcemia in such patients.