Abstract:

Objective To report the diagnosis and treatment of one case of solitary plasmacytoma of spine with amyloidosis and investigate the clinicopathological features combined with literatures. Methods and Results The patient was a 46-year-old woman. She suffered from weakness of both lower limbs, unsteady gait and numbness of toes for 20 d. MRI examination revealed an irregular mass behind the spinal cord at T_5-7 level and T_6-7 vertebral body accessory. The enhanced MRI showed obvious heterogeneous enhancement. The border was clear and spinal dura mater was compressed to shift forward. During operation, T_5-7 processus spinosus and vertebral laminae were eroded, and the cortex of bone showed "moth-eaten" erosion. The intraspinal and extradural lesion had rich blood supply, loose bone structure and intact spinal dura mater. Histologically, tumor cells were composed of intensive small cells, and focal plasmacytoid cells were seen. Flake pink staining substance was among them. Artificial cracks were common and multinuclear giant tumor cells were scatteredly distributed. Immunohistochemical analysis showed the cytoplasm of tumor cells were diffusely positive for CD138, CD38 and vimentin (Vim),scatteredly positive for leukocyte common antigen (LCA), and negative for immune globulin κ light chain(IgGκ) and λ light chain (IgGλ), CD99, S-100 protein (S-100), pan cytokeratin (PCK), epithelial membrane antigen (EMA), HMB45 and CD34. The Ki-67 labeling index was 1.25%. Congo red staining showed the pink staining substance was brownish red. Hybridization in situ examination showed the DNA content of IgGκ was more than that of IgGλ. The final pathological diagnosis was solitary plasmacytoma of spine with amyloidosis. The patient was treated with postoperative chemotherapy, and there was no recurrence or metastasis during 18-month follow-up period. Conclusions Solitary plasmacytoma of spine with amyloidosis is a rare tumor. The imaging features can offer a few diagnostic cues. However, a clear diagnosis depends on specific histomorphology, immunophenotyping, special staining and hybridization in situ examination.

Key words: Plasmacytoma, Amyloidosis, Spine, Immunohistochemistry, In situ hybridization, Pathology

摘要：

目的 报告1 例脊柱孤立性浆细胞瘤伴淀粉样变性患者的诊断与治疗过程，结合文献探讨其组织病理学特征。方法与结果 女性患者，46 岁，临床主要表现为双下肢无力，行走不稳伴脚趾麻木感。头部MRI 显示，T_{5 ~ 7} 水平脊髓后方硬脊膜外和T_{6 ~ 7} 水平附件内不规则占位性病变，增强扫描呈不均匀明显强化，边界清晰，硬脊膜受压向前移位。术中可见T_{5 ~ 7}棘突和椎板以及部分T₅、T₇棘突和椎板被侵蚀，骨皮质呈“虫蚀”样改变；病变位于椎管内硬脊膜外，血供丰富，呈疏松骨样结构，硬脊膜完整。组织学形态观察，肿瘤细胞以密集排列的小细胞为主，可见灶性浆细胞样细胞分化，其间可见片状粉染物质沉积，并多见人工裂纹和散在分布的多核巨细胞。免疫组织化学染色，肿瘤细胞胞质CD138、CD38 和波形蛋白弥漫性阳性；白细胞共同抗原散在阳性；免疫球蛋白κ轻链和λ轻链、CD99、S-100 蛋白、广谱细胞角蛋白、上皮膜抗原、黑色素瘤相关抗原HMB45 和CD34 阴性；Ki-67 抗原标记指数约1.25%。特殊染色，粉染物质刚果红染色呈棕红色。原位杂交显示免疫球蛋白κ轻链DNA 含量高于λ轻链。最终病理诊断为（脊柱）孤立性浆细胞瘤伴淀粉样变性。术后辅以药物化疗。随访18 个月肿瘤无复发和转移。结论 脊柱孤立性浆细胞瘤伴淀粉样变性临床罕见，影像学检查对诊断有一定提示意义，明确诊断仍依靠特异性组织形态学、免疫表型、特殊染色和原位杂交检测。

关键词: 浆细胞瘤, 淀粉样变性, 脊柱, 免疫组织化学, 原位杂交, 病理学