肾脏巨大恶性孤立性纤维瘤的临床病理分析

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。

Clinicopathologic Analysis of Large Malignant Solitary Fibrous Tumor of Kidney

ObjectiveTo study the clinicopathologic features and differential diagnosis of malignant solitary fibrous tumor (SFT) of kidney. MethodsA case of malignant SFT of kidney was examined with gross and light microscopy and immunohistochemistry, with related literature reviewed. ResultsGrossly, 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. ConclusionThe 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.