大切片上直肠癌远端壁内扩散的研究

目的 研究直肠癌远端壁内扩散的规律，为临床保肛手术提供依据。方法 收集广州中山医科大学肿瘤医院1996年8月－1997年10月间直肠癌手术标本98例，制成大切片，在显微镜下观察直肠癌的远端壁内扩散，运用等比回缩规律，得出活体情况下的远端壁内扩散长度。结果 98例标本中，48例发生远端壁内扩散,最短0．1cm，最长2．5cm，其中＜0．5cm者37例，≥0.5cm且＜1.0cm者6例，≥1.0cm者5例。从大切片上可以观察到肿瘤发生直接侵袭、神经侵袭、淋巴侵袭和血管侵袭。远端壁内扩散可同时或分别沿黏膜层、黏膜下层、内环肌层、外纵肌层和浆膜层进行。结论 直肠癌远壁内扩散范围大多在0．5cm以内，扩散≥1cm的很少。临床保肛手术远切缘≥3cm比较安全。

Distal intramural spread of rectal cancer studied on large slices

OBJECTIVE: To study the length of distal intramural spread of rectal cancers, and provide evidence for anal-preserving operations. METHODS: Specimens of ninety-eight patients with rectal cancers who had been operated from August, 1996 to October, 1997, were collected and their large pathologic slices examined. The length of intramural spread distal to rectal cancers was measured under light microscope. The actual length of spread in live conditions was estimated according to equal proportional shrinkage. RESULTS: In 48 of the 98 patients, distal intramural spread of the tumor was observed. The length of spread varied from 0.1 cm to 2.5 cm. In 77% of the 48 patients, the length of tumor spread was < 0.5 cm. In only 5 patients was the distance of spread > or = 1.0 cm. Four different ways of tumor invasion were observed: contiguous, lymphatic, neural and venous invasion. Distal intramural spread could be via mucosa, submucosa, inner circular muscular layer, outer longitudinal muscular layer or serosa, either separately or concomitantly. CONCLUSION: Distal intramural spread of rectal cancers can be detected in about 1/2 of the specimens examined on large pathologic slice. In most of them the distance of spread is < 0.5 cm. Occasionally it may be > or = 1 cm. To set the edge of resection > or = 3 cm distal to the rectal cancers is relatively safe in anal-preserving operations.