Yazdian Aaron, Minuk Jeffrey, Hemenway Gregory, Upadhyaya Neelam, Vaz Cherie Lisa
Department of Internal Medicine, Temple University Hospital, Philadelphia, Pennsylvania.
Section of Endocrinology, Diabetes, and Metabolism, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania.
AACE Clin Case Rep. 2022 Jun 18;8(5):210-216. doi: 10.1016/j.aace.2022.06.002. eCollection 2022 Sep-Oct.
BACKGROUND/OBJECTIVE: Ectopic tumoral production of parathyroid hormone (PTH) is rare. The incidence of hyperparathyroidism and osteitis fibrosa cystica (OFC) secondary to ectopic PTH secretion has only been reported in case reports, although infrequent.
We report a case of a well-differentiated pulmonary neuroendocrine tumor (NET) producing PTH that presented with severe hypercalcemia and OFC. Surgical removal of the pulmonary tumor resulted in resolution of hypercalcemia. Immunocytochemical analysis of the tumor tissue revealed PTH-positive staining. Recovery was complicated by severe hypocalcemia due to hungry bone syndrome.
To the best of our knowledge, this is the first documented case of a pulmonary NET causing OFC via PTH. We further describe the successful identification and resection of a rare NET and restoration of calcium homeostasis with aggressive calcium and vitamin D repletion.
Although a rare cause of severe hypercalcemia and OFC, ectopic tumoral production of PTH must be considered in the differential diagnosis. Furthermore, resection of these tumors secreting PTH can lead to a protracted and severe high risk of hungry bone syndrome, which requires aggressive treatment to maintain calcium homeostasis.
背景/目的：甲状旁腺激素（PTH）的异位肿瘤产生较为罕见。尽管不常见，但异位分泌PTH继发甲状旁腺功能亢进和囊性纤维性骨炎（OFC）的发生率仅在病例报告中有记载。
我们报告一例产生PTH的高分化肺神经内分泌肿瘤（NET）病例，该病例表现为严重高钙血症和OFC。手术切除肺部肿瘤后高钙血症得以缓解。对肿瘤组织进行免疫细胞化学分析显示PTH呈阳性染色。由于饥饿骨综合征，恢复过程因严重低钙血症而复杂化。
据我们所知，这是首例经文献记载的通过PTH导致OFC的肺NET病例。我们进一步描述了成功识别和切除罕见NET以及通过积极补充钙和维生素D恢复钙稳态的过程。
尽管是严重高钙血症和OFC的罕见病因，但在鉴别诊断中必须考虑PTH的异位肿瘤产生。此外，切除这些分泌PTH的肿瘤可导致饥饿骨综合征的长期严重高风险，这需要积极治疗以维持钙稳态。
