Case Report
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Nov 24, 2023; 14(11): 544-548
Published online Nov 24, 2023. doi: 10.5306/wjco.v14.i11.544
Calcitriol induced hypercalcemia - a rare phenomenon in lung cancer: A case report
Amulya Prakash, Farhan Khalid, Ahmad Alalwan, Husam Bader, Doantrang Du, Trishala Meghal
Amulya Prakash, Department of Internal Medicine, Haywood Regional Medical Center, Clyde, NC 28721, United States
Amulya Prakash, Farhan Khalid, Ahmad Alalwan, Husam Bader, Doantrang Du, Department of Internal Medicine, Monmouth Medical Center, Long Branch, NJ 07740, United States
Trishala Meghal, Department of Hematology-Oncology, Monmouth Medical Center, Long Branch, NJ 07740, United States
Author contributions: Alalwan A conceived the idea, did the literature search, managed the case on medical floor, contributed to case presenrtation and the introduction; Khalid F and Bader H contributed the discussion; Du D and Meghal T edited and revised the manuscript.
Informed consent statement: Informed consent was obtained by the patient.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Farhan Khalid, MD, Chief Physician, Department of Internal Medicine, Monmouth Medical Center, 200 Second Avenue, Long Branch, NJ 07740, United States. farhan.khalid.md@gmail.com
Received: July 26, 2023
Peer-review started: July 26, 2023
First decision: September 4, 2023
Revised: September 20, 2023
Accepted: October 23, 2023
Article in press: October 23, 2023
Published online: November 24, 2023
Processing time: 119 Days and 3.6 Hours
Abstract
BACKGROUND

Calcitriol-induced hypercalcemia has been rarely reported in cases of lung cancer; however, it is frequently reported in cases of lymphoid malignancy and granulomatous disease. We present a rare case of hypercalcemia associated with squamous cell cancer of the lung with elevated calcitriol level.

CASE SUMMARY

A 61-year-old Caucasian female with severe hypercalcemia of 15 mg/dL, which led to a new diagnosis of metastatic lung cancer. Since the parathyroid hormone-related peptide (PTHrP) level was minimally elevated at 2.1 pmol/L, we believe excessive calcitriol production by tumor cells was the underlying mechanism for hypercalcemia. Calcitriol was significantly elevated at 130 pg/mL with a low 25-hydroxyvitamin D level of 25.9 ng/mL and suppressed PTH level of 8 pg/mL. Corticosteroids are generally used to treat calcitriol-induced hypercalcemia, but we successfully treated our patient with bisphosphonate, highlighting the further utility of bisphosphonates in hypercalcemia treatment.

CONCLUSION

We believe that the underlying cause of hypercalcemia, in this case of metastatic squamous cell lung carcinoma, was elevated calcitriol, which was likely produced by the tumor cells. In addition to PTHrP, calcitriol levels should be included in the workup for hypercalcemia in cases of lung cancer. However, the pathophysiology and prognostic significance of dysregulated calcitriol production in solid tumors remain unclear and warrant further research. Bisphosphonate may be used as a steroid-sparing therapy even in cases of calcitriol-induced hypercalcemia and warrants further investigation.

Keywords: Hypercalcemia associated malignancy; Lung cancer; Denosumab; Calcitriol; Vitamin D; Case report

Core Tip: Our case report illuminates a rare mechanism of hypercalcemia in lung malignancies, characterized by elevated calcitriol. Despite its rarity, it sheds light on the pathophysiology of hypercalcemia in solid malignancies, notably lung cancers. To the best of our knowledge, this is the first documented case in medical literature to present this mechanism. Moreover, the successful management of this condition with bisphosphonates highlights the potential efficacy of this treatment approach for future cases involving similar symptoms. By emphasizing this novel observation, our report contributes to the expanding body of knowledge regarding hypercalcemia in lung cancers and paves the way for the development of novel therapeutic strategies for the treatment of such cases.