阑尾黏液性肿瘤的CT和MRI诊断及良恶性鉴别-CT and MRI diagnosis and differential diagnosis of benignity and malignancy of appendiceal mucinous tumors

原文图文

【摘要】目的：探讨阑尾黏液性肿瘤的CT及MRI特征，并分析其良、恶性鉴别要点。方法：回顾性分析67例经病理证实的阑尾黏液性肿瘤的临床资料，其中黏液腺癌27例，黏液性囊腺瘤22例，低级别黏液性肿瘤18例。分组对照分析CT及MRI征象并行Logistic回归分析性别、年龄、部位、大小、形态、境界、根蒂和囊壁（厚度、均匀度、光滑度、完整度）、内容物（壁结节、分隔、钙化、囊液、气体）、强化（强度、均匀性、方式）、腹水、淋巴结等因素与良、恶性的相关性。结果：黏液腺癌多表现为长茄子形，最大径6.5cm（2.9～11.2cm），长径与短径比值平均2.5。27例均囊壁不光整，边界不清，强化不均匀，多伴附壁结节样（n=11）或分隔条絮样强化（n=13），钙化(n=17)以囊内颗粒状多见（n=14），部分可见囊壁破裂形成腹腔假性黏液瘤（n=12）及腹腔种植转移（n=8）。黏液性囊腺瘤多为球形，最大径3.5cm（2.2～9.5cm），长径与短径比值平均1.65，囊壁相对光整，边界相对较清，强化较均匀；钙化（n=17）多为附壁蛋壳样钙化（n=11），腹水少见。低级别黏液性肿瘤恶性度较低，影像表现介于黏液腺癌与囊腺瘤之间， 1例穿孔但未见腹腔种植转移。Logistic回归分析提示良性组的根蒂和囊壁均匀度、光滑度及其强化均匀性与恶性组间差异有统计学意义（P<0.05）。结论:阑尾黏液性肿瘤病理上分为上述三类，CT、MRI表现有一定特征性，但术前相互鉴别困难；根蒂和囊壁的均匀度、光滑度及强化均匀性等因素对判断良恶性有帮助，由于样本量有限，其他因素的鉴别价值有待进一步研究。;【Abstract】Objective：To investigate the CT、MRI manifestations and differential diagnosis of benignity and malignancy of appendiceal mucinous tumors. Methods：The clinical,CT and MRI materials of 48 cases with pathology proved appendiceal mucinous tumor were analyzed retrospectively.There were mucinous adenocarcinoma (27 patients),mucinous cystadenoma (22 patients) and low grade mucinous tumors (18 patients).The CT and MRI manifestations were analyzed and correlated with gender,age,location,size,shape,border,peduncle and cyst wall (thickness,evenness,smoothness,integrity),intra-cystic content (mural nodule,septa,calcification,intra-cystic fluid and gas),enhancement (intensity,homogeneity,pattern),ascites,lymph nodes with Logistic regression.Results:Mucinous adenocarcinoma (n=27) usually presented as long eggplant shape with the longest dimension as 6.5cm （2.9~11.2cm）,the ratio of length and width was 2.5 on average.All of the 27 patients had irregular cystic wall,ill defined boundary,heterogeneous enhancement accompanied with mural nodular enhancement (n=11) or strip like enhancement (n=13).Calcifications were observed in 17 cases （17/27）,most of them were intra capsular granular calcification (n=14).Occasionally part of the capsule wall ruptured with intra abdominal pseudo myxoma (n=12) and implantation metastasis (n=8).Of the 22 patients with mucinous cystadenoma,spherical shape was often encountered,with biggest diameter as 3.5cm （2.2~9.5cm）,the ratio of length and width was 1.65 on average,with relatively smooth capsule wall,well defined boundary,homogeneous enhancement and calcification (n=17),most of them presenting egg shell pattern (n=11).Ascites were rarely assessed.Low grade mucinous neoplasm (n=18) had low potential malignancy,the imaging features were between those of cystadenoma and cystadenocarcinoma.Perforation was seen in one case and without implantation metastasis.Logistic regression analysis suggested that the findings including evenness of peduncle and cyst wall,smoothness,homogeneity of enhancement prompted to be benignity,showing statistically significant difference between the groups (P<0.05).Conclusion:Appendiceal mucinous tumors had the above mentioned three subtypes on pathology,characteristic CT and MRI manifestations could be displayed,but still had difficulty in differentiation of benignity and malignancy before surgery.Factors included evenness and smoothness of peduncle and cyst wall,homogeneity of enhancement were helpful for differential diagnosis.Further evaluation is necessary due to limitation of sample size in this study.