直肠癌细胞系膜内淋巴结转移的解剖病理学研究

Anatomic pathology of tumor cell spread through lymph nodes in the mesorectum of rectal cancer

目的:研究直肠癌系膜淋巴结(LN)大小、分布、转移及微转移规律. 方法:对全直肠系膜切除的直肠癌标本用LN显示液处理, 切取的LN以常规病理结合免疫组化染色检测. 结果:本组31例548枚LN,27例(87.1%)153枚(27.9%) LN发现转移.其中,直径小于0.5 cm LN 366枚(66.8%), 转移91枚(59.5%).转移病例中,后壁直肠癌15例,78 枚LN转移,75枚沿直肠上动脉分布.侧壁直肠癌12例, 75枚LN转移,同侧直肠上动脉分支、直肠中动脉旁转移37和8枚,对侧分别为9和0枚. 结论:直肠癌大部分转移LN直径小于0.5 cm,主要分布于直肠上动脉旁.LN转移与肿瘤方位有关,后壁癌可同时沿肿瘤两侧系膜扩散,侧壁癌以同侧LN受累为主.

AIM: To investigate the size, distribution, and pattern of metastases and micrometastases of lymph nodes (LNs) within the mesorectum of rectal cancer. METHODS: All rectal cancer specimens obtained by total mesorectal excision were treated with lymph node revealing solution to retrieve all LNs, which were detected with a combination use of haematoxylin and eosin staining and immunohistochemical (IHC) staining with an antibody against cytokeratin 20. RESULTS: A total of 548 LNs in 31 specimens were harvested, with 17.7 nodes per case. 153 nodes (27.9%) in 27 patients (87.1%) were found positive by routine pathological examination and IHC staining. Of all the nodes retrieved, nodes <0.5 cm numbered 366 (66.8%) with 91 (59.5%) positive. Among the 27 metastasized cases, there were 15 cases whose tumors were located in the back wall of the rectum, in which 78 nodes were detected positive with 75 nodes along the superior rectal artery. In the other 12 cases with tumors positioned in the lateral wall, 75 nodes were diagnosed positive, with 37 nodes, 8 nodes around the branch of superior rectal artery and middle rectal artery on tumor side, and 9 nodes, 0 nodes on the opposite side, respectively. CONCLUSION: The majority of tumor positive LNs in the mesorectum are <0.5 cm in diameter. LNs within the me-sorectum are distributed mainly along major supplying vessels with around the superior rectal artery most. The patterr, of lymphatic spread of rectal cancer has close relationships with tumor location in the rectal wall. Tumors in the posterior wall may spread in both sides of the mesorectum simultaneously, while tumors localized in one lateral wall tend to metastasize preferably to LNs in the mesorectum of tumor side.