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Updated: Jan 2, 2026

A Semi-Automated and Reproducible Biological-Based Method to Quantify Calcium Deposition In Vitro
Published on: June 2, 2022
Zoledronate-responsive calcitriol-mediated hypercalcemia in a 5-year-old case with squamous cell carcinoma on the
Ulkem Colak1, Gul Y Mutlu2,3, Banu O Sozmen4
1Department of Pediatrics, Koc University School of Medicine, Istanbul, Turkey.
Abstract:
Malignancy-induced hypercalcemia is a very rare condition in children whereas it is more common among adult patients with malignancy. The mechanisms of malignancy-induced hypercalcemia include the over-secretion of parathyroid hormone-related protein (PTHrP), osteolytic metastases and the over-production of 1,25-dihydroxyvitamin D (calcitriol). Although hypercalcemia due to PTHrP secretion has been published before, overproduction of calcitriol has not been reported yet in pediatric squamous cell skin carcinoma cases. Herein, we report calcitriol-mediated severe hypercalcemia in a 5-year-old boy with squamous cell skin carcinoma arising in the background of xeroderma pigmentosum (XP) which responded well to zoledronate treatment. To the best of our knowledge, this is the first pediatric case of malignancy-induced hypercalcemia which is mediated by calcitriol in squamous cell skin carcinoma.
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