Muro Bushart N, Tharun L, Oheim R, Paech A, Kiene J
Klinik für Orthopädie und Unfallchirurgie, UKSH Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Deutschland.
Institut für Pathologie, UKSH Campus Lübeck, Lübeck, Deutschland.
Orthopade. 2020 Jan;49(1):1-9. doi: 10.1007/s00132-019-03719-4.
The symptoms of muscle weakness, bone pain and fragility fractures can be an indication of osteomalacia. Phosphate is often not considered within osteologic parameters, decreased levels are therefore easily overseen. The additional test for fibroblast growth factor 23 (FGF23) as indicator for tumor-induced osteomalacia (TIO) is still largely unfamiliar.
By emphasizing the role of phosphate and furthermore FGF23 in bone metabolism illustrated by the long-term disease process of our clinical case we would like to introduce these parameters to a broader public.
We performed a literature search via PubMed and Google Scholar with the relevant key words and summarized the diagnostic and therapeutic information. The studies evaluated were mainly case reports. We present a case report of a 70-year-old patient with TIO and a myopericytoma and retrospectively analyzed the clinical case. The follow-up was 6 months.
Our literature search found one case of TIO and evidence of FGF23 among 124 cases of myopericytomas in total. Over 300 cases of TIO are reported. In our case, we retrospectively found an FGF23-secreting myopericytoma in the phosphaturic mesenchymal tumors (PMT) group to be the cause of pseudarthrosis on the right humerus shaft and increasing disablement in a patient with osteomalacia. After surgical resection the patient was mobile again, and the osteologic parameters, especially phosphate, normalized from 0.21 to 1.52 mmol/l.
Low phosphate levels are the decisive indication of TIO in our case. Therefore, we should always think of phosphate level control when dealing with osteomalacia. A hypophosphatemia and hyperphosphaturia should be recognized in time and be diagnostically verified. The additional FGF23 test (c-terminal and intact FGF23) should be considered.
肌肉无力、骨痛和脆性骨折症状可能提示骨软化症。骨代谢参数中通常不考虑磷酸盐，因此其水平降低很容易被忽视。作为肿瘤诱导性骨软化症（TIO）指标的成纤维细胞生长因子23（FGF23）的附加检测在很大程度上仍不为人所知。
通过我们临床病例的长期病程说明磷酸盐以及FGF23在骨代谢中的作用，我们希望向更广泛的公众介绍这些参数。
我们通过PubMed和谷歌学术搜索相关关键词进行文献检索，并总结诊断和治疗信息。所评估的研究主要是病例报告。我们报告一例70岁患有TIO和肌周细胞瘤的患者病例，并对该临床病例进行回顾性分析。随访时间为6个月。
我们的文献检索在总共124例肌周细胞瘤病例中发现1例TIO及FGF23证据。报告的TIO病例超过300例。在我们的病例中，我们回顾性发现磷酸尿性间叶肿瘤（PMT）组中一个分泌FGF23的肌周细胞瘤是一名骨软化症患者右肱骨干假关节形成和残疾加重的原因。手术切除后患者再次能够活动，骨代谢参数，尤其是磷酸盐，从0.21毫摩尔/升恢复正常至1.52毫摩尔/升。
在我们的病例中，低磷酸盐水平是TIO的决定性指标。因此，在处理骨软化症时我们应始终考虑控制磷酸盐水平。应及时识别低磷血症和高磷尿症并进行诊断验证。应考虑进行附加的FGF23检测（C端和完整FGF23）。
