肝脏孤立性坏死结节的影像和病理对照

Correlation between imaging and pathology of solitary necrotic nodule of liver

目的认识肝脏孤立性坏死结节的影像及病理学表现，提高诊断准确率。方法１６例中１２例经手术病理证实，４例根据ＭＲＩ表现随访半年以上证实。对照病理，分析１６例超声、ＣＴ及ＭＲＩ表现。结果组织病理显示全部为凝固坏死结节，６个病灶含有小片液化坏死，平均直径２．３ｃｍ，外周的薄层纤维包膜中有淋巴细胞、浆细胞、嗜酸性细胞及少数中性白细胞浸润。超声为内部回声欠均匀的低回声结节。ＣＴ表现为边缘清楚、无强化的低密度病灶。在ＭＲＩ的Ｔ１及Ｔ２ＷＩ上分别呈低信号及等低信号，４个病灶内间以点片状更低信号及高信号，增强后病灶内部无强化，４４％（７／１６）有细环状轻度延迟强化的包膜。结论平扫加动态增强ＭＲＩ能良好反映孤立性坏死结节的病理特征，其表现具高度的诊断特异性，明显优于超声和ＣＴ。

Purpose To understand the imaging manifestations and pathology of solitary necrotic nodule (SNN) to improve accuracy of diagnosis. Methods This series consisted of 16 cases proved by surgery and pathology in 12 cases and by follow up of above half a year in 4 cases. US, CT and MRI of 16 patients were analyzed and correlated with pathology. Results Histopathologically, the SNN presented as coagulative necrotic nodules with average diameter of 2.3 cm and enveloped by fibrous capsule infiltrated with various inflammatory cells including lymphocytes, plasma cells, acidocytes and a few neutrophils. 6 lesions contained small areas of liquid necrosis. The lesions were inhomogeneous hypoechoic on US and of low density on CT both before and after contrast injection. The margin was clearly defined. All of the nodules demonstrated hypointense and isointense signal relative to parenchyma of liver on both T 1 and T 2 weighted images. Small areas of lower and higher intensity within the lesion could be seen on both T 1 and T 2 weighted images in 4 cases. After Gd DTPA administration, there was no enhancement excepta thin delayed enhanced capsule( 7/16, 44%). Conclusion Findings of both plain and dynamic enhanced MRI can correlate well with pathologic characteristics and are highly specific for diagnosis of SNN obviously superior to US and CT.