Supplementary Material for: Parathyroid Hormone-Related Protein-Producing Adenocarcinoma Suspicious of Lung Cancer - case report -

Introduction; Lung adenocarcinoma with PTH-related hypercalcemia is uncommon.
Case presentation; A 69-year-old man was admitted to our hospital due to anorexia and fatigue. Serum calcium (15.0mg/dl) and carcinoembryonic antigen (361.7 ng/ml) were extremely high and PTH-rP also elevated (16.7 pmol/l). Systemic computed tomography (CT) revealed multiple enlarged lymph nodes and disseminated peritoneal nodules, with irregularly shaped nodules in the upper lobe in left lung. Ultrasound-guided biopsy from the axillary lymph node revealed adenocarcinoma. Immunohistological staining showed the tumor cells to be positive for cytokeratin 7 and PTH-rP, and negative for cytokeratin 20 and thyroid transcription factor-1. Although the primary origin remains undetermined despite detailed examinations, possible primary tumor was considered to be lung adenocarcinoma in the present case. Serum calcium level was reduced by denosumab, but the patient died 20 days after admission.
Conclusion; The present case demonstrated the importance of considering oncological emergency, such as hypercalcemia and/or PTH-rP-producing hypercalcemia, in patients with adenocarcinoma.

引言：伴甲状旁腺激素相关性高钙血症（PTH-related hypercalcemia）的肺腺癌（lung adenocarcinoma）较为罕见。
病例报告：1例69岁男性因食欲减退、乏力入住我院。其血清钙水平达15.0mg/dl、癌胚抗原（carcinoembryonic antigen）达361.7ng/ml，均显著升高，甲状旁腺激素相关蛋白（parathyroid hormone-related protein, PTH-rP）亦升至16.7pmol/l。全身计算机断层扫描（computed tomography, CT）可见多发淋巴结肿大、腹膜弥漫性结节，左肺上叶存在不规则形结节。超声引导下腋窝淋巴结活检结果提示腺癌。免疫组化染色显示，肿瘤细胞细胞角蛋白7（cytokeratin 7）与PTH-rP呈阳性表达，细胞角蛋白20（cytokeratin 20）及甲状腺转录因子-1（thyroid transcription factor-1）呈阴性表达。尽管经详细检查仍未明确原发肿瘤来源，但本例考虑原发灶可能为肺腺癌。予以地诺单抗（denosumab）治疗后，血清钙水平有所降低，但患者于入院后20天死亡。
结论：本例提示，对于腺癌患者，需警惕高钙血症及（或）PTH-rP相关性高钙血症这类肿瘤急症的发生。