肾脏巨大恶性孤立性纤维瘤的临床病理分析

Clinicopathologic Analysis of Large Malignant Solitary Fibrous Tumor of Kidney

目的探讨肾恶性孤立性纤维瘤的临床病理学特征以及鉴别诊断。方法对1例肾恶性孤立性纤维瘤进行大体及镜下观察,并作免疫组织化学染色,结合文献进行复习。结果肉眼检查,肾脏被巨大肿块所取代,大小20cm×12cm×9cm,界限尚清,切面灰白灰黄色,可见多灶状坏死及直径0.6-1cm的小囊腔,质地细腻、软而脆。镜下表现为细胞稀疏区与密集区交错分布,梭形瘤细胞密集区排列成束状,束与束相互交错;疏松区间质黏液变性;细胞间有纤细至短束的胶原纤维;细胞核有轻-中度异型性,核分裂相4-6个/HPF,有多灶状肿瘤性坏死;无明显的血管外皮瘤样结构;可见到脂肪细胞化生及囊性变。免疫组织化学染色,瘤细胞Vimentin、CD99、Bcl-2弥漫阳性,CD34部分阳性,S100小灶状阳性。结论肾恶性孤立性纤维瘤非常少见,肿瘤体积大于10cm提示对恶性判断有参考意义;需与其他恶性梭形细胞肿瘤进行鉴别诊断。病理形态学特点及免疫组织化学染色可有助于鉴别。

Objective To study the clinicopathologic features and differential diagnosis of malignant solitary fibrous tumor（SFT） of kidney.Methods A case of malignant SFT of kidney was examined with gross and light microscopy and immunohistochemistry,with related literature reviewed.Results Grossly,the kidney was replaced by a large mass of 20cm×12cm×9cm,poorly circumscribed with the color of grey-white and grey by yellow on the cut surface and multi-foci of necrosis.The diameter of cysts ranged from 0.6cm to 1.0cm.The texture was delicate and tender.Microscopically,alternating hypo-and hypercelluar areas,the tumor was composed of bland spindle-shaped cells,and was col-overlap in hypercellular areas.Mucoid degeneration were in hypocelluar areas.Fine and cluster collagen was within intercyte.The tumor had heteromorphism of low-midddle deree,with numerous mitoses 4 to 6 per 10 high-power fields and multi-foci of necrosis.The hemangiopericytoma-lik structure was scarced,with the area of cystic and fatty degeneration.Immunohistochemical analysis showed that the tumor cells were diffusely positive for Vimentin,CD99,Bcl-2,and meri-positive for CD34 and micro-focus positive for S100.Conclusion The malignant SFT of the kidney is very rare and the more-than-10cm-diametered tumor may be helpful for assessing malignant SFT.It need to be distinguished from other malignant spindle cell tumors of the kidney.Diagnosis is based on its morphology and immunohischemistry.