Hypercalcemia Owing to Overproduction of 1,25-Dihydroxyvitamin D3 in Fetal Lung Adenocarcinoma: Case Report

Tomohito Saito; Mistuaki Ishida; Makiko Kusabe; Takahiro Utsumi; Natsumi Maru; Hiroshi Matsui; Yohei Taniguchi; Takayasu Kurata; Hiroaki Kurokawa; Takanobu Imada; Koji Tsuta; Hiroyasu Tsukaguchi; Tomohiro Murakawa

doi:10.1016/j.jtocrr.2021.100204

Hypercalcemia Owing to Overproduction of 1,25-Dihydroxyvitamin D₃ in Fetal Lung Adenocarcinoma: Case Report

JTO Clin Res Rep. 2021 Jul 5;2(8):100204. doi: 10.1016/j.jtocrr.2021.100204. eCollection 2021 Aug.

Affiliations

¹ Department of Thoracic Surgery, Kansai Medical University Hospital, Osaka, Japan.
² Department of Pathology, Kansai Medical University Hospital, Osaka, Japan.
³ Department of Nephrology, Kansai Medical University Hospital, Osaka, Japan.
⁴ Department of Thoracic Oncology, Kansai Medical University Hospital, Osaka, Japan.
⁵ Department of Radiology, Kansai Medical University Hospital, Osaka, Japan.

Abstract

Hypercalcemia is a common electrolyte abnormality in malignancy and is largely caused by activation of parathyroid hormone (PTH) pathways. We report the case of a 76-year-old man with hypercalcemia primarily owing to 1,25-dihydroxyvitamin D₃ overproduction from a high-grade fetal lung adenocarcinoma. Histologically, the tumor itself and tumor-adjacent macrophages were positive for the CYP27B1 protein, a key enzyme that generates 1,25-dihydroxyvitamin D₃. Suppression was observed in serum PTH and PTH-related hormone levels, suggesting hypercalcemia is independent of the PTH pathway. Serum calcium level returned to normal after surgical resection of the lung cancer, supporting extrarenal overproduction of 1,25-dihydroxyvitamin D₃ elicited by the tumors is the cause of hypercalcemia in this patient.

Keywords: 1,25-Dihydroxyvitamin D3; Case report; Hypercalcemia of malignancy; Lung cancer.

Publication types

Case Reports