Nagelberg Steven B, Biscoveanu Mihaela, Bix Barbara, Andrews Carrie, Prasad Srinivas
Northeast Endocrine Metabolic Associates of Thomas Jefferson University, Philadelphia, PA.
Holland Medical Associates, Feasterville, PA.
JCEM Case Rep. 2025 Sep 1;3(10):luaf179. doi: 10.1210/jcemcr/luaf179. eCollection 2025 Oct.
A 73-year-old woman with a remote history of successfully treated primary hyperparathyroidism was referred to our office because of multiple skeletal fractures and proximal muscle weakness. Prior laboratory evaluation demonstrated hypocalcemia, vitamin D deficiency, elevated PTH, and elevated alkaline phosphatase. Updated evaluation in our clinic additionally showed hypophosphatemia prompting measurement of serum fibroblast growth factor 23 (FGF23). FGF23 proved to be markedly elevated prompting consideration of tumor-induced osteomalacia. Positron emission tomography with Cu-64 oxodotreotide revealed an enhancing focus in the left thoracic spine that was confirmed on magnetic resonance imaging to be a 1.5-cm extradural mass. The patient underwent surgical resection of the mass by the neurosurgery spine service. Pathologic analysis demonstrated a 2.4-cm mesenchymal tumor; mRNA in situ hybridization was positive for FGF23. Laboratory studies 12 weeks postoperatively showed near normalization of the serum FGF23 as well as improvement in her other metabolic abnormalities and clinical symptomatology. This case exemplifies the necessity of measurement of serum inorganic phosphate and a high level of suspicion for hypophosphatemic osteomalacia in patients with numerous fractures beyond that expected for their degree of osteoporosis.
一名有原发性甲状旁腺功能亢进症成功治疗史的73岁女性，因多处骨骼骨折和近端肌肉无力前来我处就诊。之前的实验室检查显示低钙血症、维生素D缺乏、甲状旁腺激素升高以及碱性磷酸酶升高。我们诊所的最新评估还显示低磷血症，促使检测血清成纤维细胞生长因子23（FGF23）。结果显示FGF23显著升高，提示考虑肿瘤诱导的骨软化症。用Cu-64奥曲肽进行正电子发射断层扫描显示左胸椎有一个强化灶，磁共振成像证实为一个1.5厘米的硬膜外肿块。患者接受了神经外科脊柱团队对该肿块的手术切除。病理分析显示为一个2.4厘米的间叶性肿瘤；FGF23的mRNA原位杂交呈阳性。术后12周的实验室检查显示血清FGF23接近正常，其他代谢异常和临床症状也有所改善。该病例体现了对于骨折数量超过预期骨质疏松程度的患者，检测血清无机磷以及高度怀疑低磷性骨软化症的必要性。
