反复阅读，很有收获！感谢各位老师！

 Histopathology. 2007 Jan;50(1):131-50.

Colorectal serrated adenocarcinoma.

• Makinen MJ.

 
Colorectal cancer (CRC) ranks among the three most common cancers in terms of both cancer incidence and cancer-related deaths in most Western countries. Serrated adenocarcinoma is a recently described, distinct variant of CRC, accounting for about 7.5% of all CRCs and up to 17.5% of most proximal CRCs. It has been postulated that about 10-15% of sporadic CRCs would have their origin in serrated polyps that harbour a significant malignant potential. These lesions include hyperplastic-type aberrant crypt foci, hyperplastic polyps, sessile serrated adenomas, admixed polyps and serrated adenomas, and constitute the so-called 'serrated pathway', which is distinct from both the conventional adenoma-carcinoma pathway and the mutator pathway of hereditary non-polyposis CRC and is characterized by early involvement of oncogenic BRAF mutations, excess CpG island methylation (CIM) and subsequent low- or high-level DNA microsatellite instability (MSI). Methylation of hMLH1 is likely to explain the increased frequency of high-level MSI (16%) and methylation of MGMT is postulated to explain the low-level MSI (29%) in serrated adenocarcinomas. Reproducible histopathological criteria for serrated adenocarcinoma have recently been established and they have been qualified by DNA expression analysis for 7928 genes, showing clustering of serrated adenocarcinomas into a molecular entity apart from conventional adenocarcinoma, and representing with distinct down-regulation of EPHB2, PTCH and up-regulation of HIF1alpha.

 

锯齿状腺瘤癌变第一次看到。谢谢椰子树老师。

 谢谢zhanglei老师讲解

 谢谢fangg  

  锯齿状腺瘤

 经典！谢谢提供！

 这里有这么多好的老师和病例，真是太好了！！！

 受教了

 锯齿状腺瘤

 第一次看到,学习了,谢谢!

 

同意 感觉图太小，看的不是很清楚，感觉不象腺瘤，倾向增生性息肉。

 向华夏网里所有热心的老师们致敬!

 锯齿状腺瘤

增生性息肉（右侧结肠）－－》常常B-RAF基因突变－－》无蒂锯齿状腺瘤－－》高度微卫星不稳定性 －－》腺癌（生长快，肿块以突向肠腔为主，预后好）。

增生性息肉（左侧结肠）－－》常常K-RAS基因突变－－》有蒂锯齿状腺瘤－－》低度微卫星不稳定性或微卫星稳定性 －－》腺癌（生长慢，肿块以浸润肠壁为主，预后差）。

 谢谢各位老师的精彩讲解，以后遇到绝对能诊断准确。

 学习。