Hypercalcemia of Malignancy: Simultaneous Elevation in Parathyroid Hormone-Related Peptide and 1,25 Dihydroxyvitamin D in Sarcoma

OBJECTIVE: Hypercalcemia is a common finding in patients who have an underlying malignancy. Only a few cases of hypercalcemia of malignancy have been linked to more than one mechanism of hypercalcemia. Here, we present a patient with liposarcoma and hypercalcemia of malignancy in the setting of simultaneous elevations in parathyroid hormone-related peptide (PTHrP) and 1,25 dihydroxyvitamin D [1,25(OH)(2)D] levels. Sarcoma-associated hypercalcemia is a rare disorder. METHODS: The patient was an 89-year-old woman with sarcoma-associated hypercalcemia. Multiple mechanisms were uncovered, and treatments were adjusted for them. Literature search for hypercalcemia of malignancy with multiple mechanisms was conducted. RESULTS: This is the first report describing dual mechanisms of sarcoma-associated hypercalcemia and only the fifth report on PTHrP and 1,25(OH)(2)D simultaneously causing hypercalcemia of malignancy. CONCLUSION: Based on this finding, we recommend measuring the 1,25(OH)(2)D levels in conjunction with the PTHrP level in patients with malignancy as this would allow for a more proactive approach to the diagnosis and treatment of hypercalcemia of malignancy.