Abstract: SA-PO694
Calcitriol-Mediated Hypercalcemia in Mesothelioma
Session Information
- Fluid, Electrolyte, Acid-Base Disorders: Clinical - II
November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Author
- Parveen, Fnu, Baylor College of Medicine, Houston, Texas, United States
Introduction
Hypercalcemia (hyperca) is common in several hematological and solid organ malignancies however hyperca has rarely been reported in mesothelioma. We report an unusual case of calcitriol mediated hyperca in mesothelioma.
Case Description
An 80-year-old gentleman with stage IV chronic kidney disease was admitted for severe hyperca.Serum calcium (Ca)corrected for hypoalbuminemia 15 mg/dL.He was diagnosed with right lung mesothelioma two months prior followed by first cycle of nivolumab/ipilimumab(Nivo/Ipli) a month prior.
He had mild hyperca 6 months prior to mesothelioma diagnosis which progressed despite stopping vitamin D and Ca supplementation. Workup shown in Table 1.
Initial imaging revealed concern for lytic lesions of pelvis however subsequent workup including serum free light chains, serum and urine protein electrophoresis, bone and PET scan were negative for plasma cell dyscrasias.
Further Imaging revealed 2.3cm left renal mass suspicious of renal cell carcinoma (RCC) however PET scan did not show any uptake into the kidneys. After acute treatment of hyperca the patient continued treatment with immunotherapy(IT) to which he responded.
Discussion
Hyperca from malignancy occurs from either tumor secretion of parathyroid hormone-related protein or tumor production of calcitriol etc. Calcitriol induced hyperca from Nivo/Ipli has also been reported.
In our case calcitriol mediated hyperca from mesothelioma is the most plausible etiology. Even though calcitriol levels prior to IT are not available hyperca developed prior to starting IT. Workup of hematologic malignancy was negative and PET scan did not show FDG uptake by the renal mass. Finally his Ca levels improved with further IT and improvement in mesothelioma. Although FDG uptake in RCC has a lower sensitivity and Nivo/Ipli can also treat RCC we believe the time-course of events makes mesothelioma the more plausible etiology.
Table 1
| Test | Value |
| Calcium (mg/dL) | 14.3 |
| Albumin (g/dL) | 2.8 |
| Corrected Calcium (mg/dL) | 15.3 |
| Ionized Calcium (mg/dL) | 7.1 |
| Phosphorus (mg/dL) | 3.6 |
| PTH (pg/mL) | 16.6 |
| PTHrP (pmol/L) | <2 |
| 25-hydroxyvitamin D (ng/mL) | 52.7 |
| 1,25-hydroxyvitamin D (pg/mL) | 83.4 |
| Serum and Urine Protein Electrophoresis | No monoclonal spike identified |