静脉侵袭（VI）是结直肠癌（CRC）中一个强而有力但报道不足的预后因子。改善其检测的努力主要集中在组织学评估，对组织取样策略的关注较少。本研究旨在前瞻性确定CRC切除手术中优化VI检测所需的肿瘤块数，并探讨线性星芒（LS）与外层静脉侵袭（EMVI）之间的关系。我们制定了并应用了标准化的组织取样方案，对217例CRC切除手术进行了前瞻性研究（AJCC第8版，分期1期（n = 32）；分期2期（n = 84）；分期3期（n = 87）；分期4期（n = 14）；和术后新辅助治疗（n = 46））。在所有肿瘤块上进行了弹性蛋白染色。在其中的55%的病例中发现了VI（EMVI = 37%；仅IMVI = 18%）。随着提交的肿瘤块数量增加，VI检测的敏感性也增加[一个块（35%），三个块（66%），五个块（84%），六个块（95%）和七个块（97%）]。EMVI的结果也显示了类似的发现[一个块（35%），三个块（73%），五个块（89%），六个块（96%）和七个块（96%）]。显微镜下，22%的标本中可以宏观看到LS。在未进行新辅助治疗的病例中，EMVI与LS显著相关（LS阳性病例为71%，LS阴性病例为29%；P < 0.001）。此外，针对LS的肿瘤块与未针对LS的肿瘤块相比，EMVI的发生率高五倍（P < 0.001）。我们的发现证明了组织取样和镜检质量对VI检测的影响，为未来的CRC方案制定提供了参考。 © 2023 The Authors. 由John Wiley & Sons Ltd.出版的《组织病理学》刊登。

Venous invasion (VI) is a powerful yet under-reported prognostic factor in colorectal cancer (CRC). Efforts to improve its detection have largely focused upon histological assessment, with less attention paid to tissue-sampling strategies. This study aimed to prospectively determine the number of tumour blocks required to optimise VI detection in CRC resections. In addition, the relationship between linear spiculation (LS) and extramural venous invasion (EMVI) was investigated.A standardised tissue sampling protocol was developed and applied prospectively to 217 CRC resections [AJCC 8th edition, stage 1 (n = 32); stage 2 (n = 84); stage 3 (n = 87); stage 4 (n = 14); and post-neoadjuvant therapy (n = 46)]. Elastin stains were performed on all tumour blocks. VI was identified in 55% of cases (EMVI = 37%; IMVI alone = 18%). The sensitivity of VI detection increased with increasing numbers of tumour blocks submitted [one block (35%), three blocks (66%), five blocks (84%), six blocks (95%) and seven blocks (97%)]. Similar findings were observed for EMVI [one block (35%), three blocks (73%), five blocks (89%), six blocks (96%) and seven blocks (96%)]. LS was identified macroscopically in 22% of specimens. In cases where no neoadjuvant therapy had been given, EMVI was significantly associated with LS (71% in LS+ cases versus 29% in LS- cases; P < 0.001). In addition, tumour blocks targeting LS were associated with a fivefold higher rate of EMVI compared with blocks that did not (P < 0.001).Our findings demonstrate the impact of tissue sampling and quality of gross examination on VI detection and may inform practices in future CRC protocols.© 2023 The Authors. Histopathology published by John Wiley & Sons Ltd.