Hypercalcemia of malignancy in metastatic esophageal squamous cell carcinoma with simultaneous PTHrP and calcitriol overproduction: A case report with literature review. (August 2021)

• Record Type: Journal Article
• Authors: Song, Runbo; Bijay, Yadav; Rizk, Sophia H.; Cao, Shanjin
• Is Part Of: Annals of medicine and surgery. Volume 68(2021)
• Publication Date: 2021-08
• Subjects: Hypercalcemia of malignancy -- Parathyroid hormone-related peptide -- 25-Hydroxyvitamin D -- 1, 25-Dihydroxyvitamin D -- Calcitriol -- Esophageal squamous cell carcinoma; Surgery -- Periodicals; Medicine -- Periodicals; General Surgery -- Periodicals; Education, Medical -- Periodicals; Periodicals; 617
• DOI: 10.1016/j.amsu.2021.102667
• Languages: English
• ISSNs: 2049-0801

Abstract

Abstract: Introduction and importance: hypercalcemia of malignancy is a severe complication of malignancy and associated with poor prognosis. Four mechanisms are implicated in this metabolic disorder, including excess parathyroid-related peptide secretion, focal osteolysis secondary to bone metastasis or multiple myeloma, excess calcitriol production, and ectopic parathyroid hormone production. Humoral hypercalcemia of malignancy secondary to isolated PTHrP or calcitriol overproduction is known; however, hypercalcemia of malignancy due to simultaneous PTHrP and calcitriol overproduction is less well known. Case presentation: we report a case of a 63-year-old male who was diagnosed with poorly differentiated esophageal squamous cell carcinoma with simultaneous PTHrP and calcitriol overproduction. Clinical discussion: while hypercalcemia of malignancy secondary to simultaneous PTHrP and calcitriol secretion has been reported in other solid cancers, this is the first case of humoral hypercalcemia of malignancy secondary to simultaneous PTHrP and calcitriol secretion associated with esophageal cancer. This phenomenon deserves increased recognition as it has both diagnostic and therapeutic consequences. We discuss the current testing algorithm and its limitations in determining the etiology of hypercalcemia of malignancy since it may miss the diagnosis of simultaneous PTHrP and calcitriol production. Conclusion: we propose a revised testing algorithm for hypercalcemia of malignancy, which may improve the identification of simultaneous overproduction of PTHrP and calcitriol. This new algorithm can better characterize the mechanisms of hypercalcemia of malignancy and more appropriately guide treatment. Highlights: Hypercalcemia of malignancy with simultaneous PTHrP and calcitriol production merits better recognition for both diagnostic and therapeutic purposes. A case of hypercalcemia of metastatic esophageal squamous cell carcinoma with simultaneous PTHrP and calcitriol is reported. The current testing algorithm and its limitations of hypercalcemia of malignancy is discussed, and a revised one is proposed.