黏液纤维肉瘤的MRI表现与组织病理学对照

摘要

Object : To explore the features of myxofibrosarcoma (MFS) on MRI and correlation with histopathology.Methods : Clinical records , MRI and histopathology data of 8 cases of MFS ( low-grade 4 , intermediate-grade 2 and high-grade 2) confirmed by surgery and pathology were retrospectively analyzed. Results: MRI: except that one case of high-grade tumor located in the deep layer, the other 7 cases were located in the superficial layer. All tumors had huge volume, the average diameter was 5.0 cm × 7.5cm. 3 cases ( 1 intermediate-grade tumor and 2 high-grade tumors) had marked lobulation , and their borders with surrounding tissues were unclear,the others 5 cases had well-defined margin and no definite lobulation.All tumors showed mixed inner signals and were enhanced inhomogeneously on MRI. The low-grade and intermediate-grade MFS showed a mixed distribution of areas of enhancement and non-enhancement. The high-grade MFS showed enhanced nodular area and non-enhanced area. Histopathology: MFS consisted of hypocellular myxoid matrix and hypercellular area.The low-grade MFS showed expansive growth with clear border,and hypocellular to moderately cellular architecture with a predominant myxoid matrix;The high-grade MFS showed invasive growth with unclear border,and more solid hypercellular architecture with a small myxoid matrix. The growth pattern and morphology of intermediate-grade tumor was between the former two. Conclusion: MRI features of MFS are closely related with pathology characters. MRI can show the extent of the tumors' invasion and surrounding satellite lesions, which provide imaging support for pathological grading.%目的:探讨黏液纤维肉瘤(MFS)的MRI表现与组织病理学的联系.方法:回顾性分析8例经手术病理证实的MFS(低度恶性4例,中度恶性2例和高度恶性2例)临床、MRI及病理资料.结果:MRI表现:除1例高度恶性MFS位置较深外,其余7例均较表浅;肿瘤体积较大,平均5.0cm×7.5cm;3例MFS(1例中度恶性,2例高度恶性)分叶明显,与周围组织分界不清,余5例分叶不明显,与周围组织分界清楚;8例MFS内部信号均较混杂,增强后强化不均,低度及中度恶性MFS示强化区与无强化区交织分布,高度恶性MFS示明显结节样强化区及无强化区.病理表现:MFS内部存在黏液样基质占优势的细胞疏松区和肿瘤细胞占优势的细胞密集区,其中低度恶性肿瘤边界清晰,膨胀性生长,内部含有明显占优势的黏液样基质和少量细胞密集区,呈交替分布;而高度恶性肿瘤呈浸润性生长,边界不清晰,有较多的结节样的细胞密集区;中度恶性肿瘤生长方式与形态介于前两者之间.结论:MFS的MRI表现与其组织病理学密切相关,MRI显示MFS的侵袭范围及周围卫星灶可为其病理分级提供影像学支持.