Inoue Takashi, Nagai Koichi, Momoi Akihito, Isahai Noriatsu, Sakai Takeshi, Sekiya Masao
Department of Internal Medicine, Niigata Prefectural Central Hospital.
Rinsho Ketsueki. 2015 Apr;56(4):418-22. doi: 10.11406/rinketsu.56.418.
Solitary/multiple plasmacytoma of bone, a rare disease as compared to multiple myeloma, is characterized by monoclonal proliferation of plasma cells in local legion (s) of bone, with no bone marrow abnormalities. Monoclonal gammagloblinemia is often absent in these conditions, and useful examinations allowing evaluation of responses to treatment are as yet lacking. Recently, 18F-FDG PET/CT (PET/CT) was reported to be useful for detecting bone lesions. PET/CT is also valuable for predicting the outcomes of patients with solitary plasmacytoma, when applied in combination with the serum free light chain (sFLC) κ/λ ratio. We present a 62-year-old male with multiple plasmacytoma of bone (MPB), in whom PET/CT and the sFLC κ/λ ratio were useful for evaluating the response to treatment. The patient was diagnosed with MPB, with PET/CT showing multiple abnormal tracer uptakes in the scapula, spine, and ribs. The sFLC ratio was markedly elevated, with the κ chain level being especially high. We administered bortezomib and dexamethasone, after which the abnormal uptakes on PET/CT disappeared. The sFLC ratio and the FLC value also normalized, and have remained stable for more than one year, to date, since treatment. In our case, PET/CT and the sFLC κ/λ ratio were found to be extremely useful for monitoring treatment responses.
骨孤立性/多发性浆细胞瘤是一种与多发性骨髓瘤相比较为罕见的疾病，其特征为浆细胞在局部骨组织中呈单克隆增殖，且无骨髓异常。在这些情况下通常不存在单克隆丙种球蛋白血症，并且目前仍缺乏有助于评估治疗反应的检查方法。最近，有报道称18F-FDG PET/CT（PET/CT）对检测骨病变有用。当与血清游离轻链（sFLC）κ/λ比值联合应用时，PET/CT对预测孤立性浆细胞瘤患者的预后也很有价值。我们报告一例62岁男性骨多发性浆细胞瘤（MPB）患者，PET/CT和sFLC κ/λ比值对评估其治疗反应很有用。该患者被诊断为MPB，PET/CT显示肩胛骨、脊柱和肋骨有多处异常示踪剂摄取。sFLC比值明显升高，κ链水平尤其高。我们给予硼替佐米和地塞米松治疗，之后PET/CT上的异常摄取消失。sFLC比值和FLC值也恢复正常，自治疗以来至今已稳定超过一年。在我们的病例中，发现PET/CT和sFLC κ/λ比值对监测治疗反应非常有用。
