59例软组织肉瘤的MRI特征与组织病理分级的关系

背景与目的:软组织肉瘤的边缘部生长方式是影响肿瘤局部复发、转移的重要影响因子。本研究采用MRI检查探讨软组织肉瘤边缘表现与肿瘤病理分级之间的相关关系,以便在术前能对软组织肉瘤的生物学特性进行评估。方法:对59例软组织肉瘤患者进行MRI检查,应用自旋回波(SE)序列,采集T1加权(T1W)、T2加权(T2W)图像。在MRI图像上对软组织肉瘤的肿瘤边界、T2W图像上瘤周高信号征象、瘤周低信号包膜征象进行分析。59例软组织肉瘤均经手术病理证实,根据组织切片表现对软组织肉瘤进行病理分级。结果:软组织肉瘤的病理分级与肿瘤边界的清晰程度有关(P<0.05),60.0%Ⅰ级肿瘤其边界清晰,而60.0%Ⅲ级肿瘤其边界不清楚。Ⅱ级与Ⅲ级肿瘤的瘤周高信号征象、瘤周包膜样低信号征象的出现率差异均无统计学意义(P>0.05)。Ⅰ级肿瘤的瘤周高信号征象、瘤周包膜样低信号征象的出现率均明显不同于Ⅱ、Ⅲ级肿瘤,两者之间差异均具有显著性(P<0.05),Ⅰ级肿瘤瘤周高信号征象、包膜样低信号征象的出现率分别为10.0%、80.0%,而Ⅱ及Ⅲ级肿瘤瘤周高信号征象、包膜样低信号征象的出现率分别为74.4%、15.4%。结论:软组织肉瘤的边缘形态特点与组织病理学分级有关,可在一定程度上反映肿瘤组织的生物学特性。

Correlation of MRI features to histopathologic grade of soft tissue sarcoma

BACKGROUND & OBJECTIVE: Peripheral tumor growth pattern plays an important role in the local recurrence and metastases of soft tissue sarcoma. This study was to determine the peripheral growth pattern of soft tissue sarcoma by magnetic resonance imaging (MRI), explore its correlation to histological grade, and assess biological features of soft tissue sarcoma before operation. METHODS: MRI was performed in 59 patients with soft tissue sarcoma. T1- and T2-weighted images were obtained using a spin-echo (SE) pulse sequence. Tumor margin, peritumoral high signal intensity sign and peritumoral low signal intensity capsule-like sign were evaluated on MR images. All patients were confirmed and graded by histopathology. RESULTS: The histological grade of soft tissue sarcoma was closely related to the margin appearance (P<0.05): the margin was well defined in 60.0% grade I tumors, and poorly defined in 60.0% grade III tumors. No significant difference in the occurrence rates of peritumoral high signal intensity sign and peritumoral low signal intensity capsule-like sign was found between grade II and grade III tumors (P>0.05). The occurrence rate of peritumoral high signal intensity sign was significant lower and that of peritumoral low signal intensity capsule-like sign was significant higher in grade I tumors than in grade II-III tumors (10.0% vs. 74.4%, 80.0% vs. 15.4%, P<0.05). CONCLUSION: The peripheral tumor growth pattern is related with histological grade, and may reflect the biological behaviors of soft tissue sarcoma.