Tandon Prabhat K, Rizvi Ali A
Division of Endocrinology, Diabetes, and Metabolism, University of South Carolina School of Medicine, Columbia, South Carolina, USA.
Endocr Pract. 2005 Jul-Aug;11(4):254-8. doi: 10.4158/EP.11.4.254.
To report the occurrence of hypocalcemia in a patient with metastatic prostate cancer, discuss its pathogenesis, and review the related medical literature.
An 82-year-old man with a known history of prostate cancer was found to have a serum calcium level of 5.4 mg/dL during an admission to the hospital for small bowel obstruction. A thorough review of his medical history revealed a temporal relationship between the diagnosis of malignant disease and progressive hypocalcemia. A complete evaluation was performed, including laboratory and imaging studies, to ascertain the cause of the hypocalcemia.
The patient had no history of hypocalcemia before the diagnosis of, and initiation of antiandrogen therapy for, advanced prostate cancer. Serum magnesium and phosphorus levels were within normal limits. The serum calcium level responded to therapy in the hospital but remained between 5.8 and 7.1 mg/dL. The parathyroid hormone level was normal, and the 25-hydroxyvitamin D value was low. A 24-hour urine collection showed substantially reduced calcium excretion, and a whole-body bone scan revealed widespread metastatic deposits. These findings were compatible with hypocalcemia related to prostate cancer and bone metastatic lesions.
This case serves as a reminder that hypocalcemia can be a manifestation of prostate cancer metastatic to bone. In contrast to the occurrence of secondary hyperparathyroidism in this setting, however, this patient had normal levels of parathyroid hormone. Review of similar previous reports and the causes and implications of a possible functional hypoparathyroid state are discussed.
报告一例转移性前列腺癌患者发生低钙血症的情况，讨论其发病机制，并复习相关医学文献。
一名82岁有前列腺癌病史的男性因小肠梗阻入院时，血清钙水平为5.4mg/dL。全面回顾其病史发现恶性疾病诊断与进行性低钙血症之间存在时间关联。进行了包括实验室和影像学检查在内的全面评估，以确定低钙血症的病因。
该患者在诊断晚期前列腺癌并开始抗雄激素治疗之前无低钙血症病史。血清镁和磷水平在正常范围内。住院期间血清钙水平对治疗有反应，但仍维持在5.8至7.1mg/dL之间。甲状旁腺激素水平正常，25-羟维生素D值较低。24小时尿钙收集显示钙排泄大幅减少，全身骨扫描显示广泛的转移灶。这些发现与前列腺癌和骨转移灶相关的低钙血症相符。
该病例提醒我们低钙血症可能是前列腺癌骨转移的一种表现。然而，与这种情况下继发性甲状旁腺功能亢进的发生不同，该患者甲状旁腺激素水平正常。讨论了对类似既往报告的回顾以及可能的功能性甲状旁腺功能减退状态的原因和影响。
