Due to the limitation of the specialty, this article mainly talks about the pathology of postoperative gastrocolorectal tumor.
1.Gastrointestinal microscopy checklist is generally not available for lymph node pathology because biopsy can only take surface mucosa.
In recent years, ultrasound endoscopy is becoming more and more important, which can perform fine needle aspiration pathology on lymph nodes or masses outside the wall of gastrointestinal canal. This gives the lymph node pathology results.
The lymph node pathology result depends on the total number, the number of positives, and the percentage of positives
2.Lymph node enlargement, not necessarily metastasis
Most of the lymph nodes with metastasis will be enlarged and hardened, but after the appearance of tumor, the local mucosal barrier will be defective, which will trigger the inflammatory reaction and also stimulate the enlargement of lymph nodes. Even if many enlarged lymph nodes are found in CT or MRI examination before surgery, or during surgery, it is not necessarily metastasis.
3. The total number of lymph nodes is related to the scope of surgery, and also related to the nature of tumor and preoperative treatment.
Total number of lymph nodes: It is the total number of lymph nodes that can be recognized by the naked eye during pathological examination. The resected specimens should be cleaned carefully and each lymph node should be pathologically examined. A certain amount of lymph nodes are examined so that the results can have better evaluation value. Enlarged lymph nodes will be more easily detected, and of course, enlargement does not mean tumor metastasis.
The total number of lymph nodes is related to the quality of surgery, but not necessarily the more the better, the less the worse the quality of surgery. There are accepted standards for how wide the lymph nodes need to be cleared for gastrointestinal tumor surgery. Exceeding the range is unnecessary and increases the risk of surgery.
There are types of tumors that result in enlarged lymph nodes and a greater number of lymph nodes can be found when clearing them, for example, there will be more lymph nodes on specimens from the right half of the colon (cecum, ascending colon, right half of the transverse colon) than the left half, and there will be more tumors with microsatellite instability features (MSI-H).
Lymph nodes with obstruction will be much more numerous to detect because of inflammatory enlargement.
In cases where radiotherapy or chemotherapy was done before surgery, there may be fewer lymph nodes. For example, after radiotherapy for low rectal cancer, the number of detectable lymph nodes may not reach 12 as needed for optimal pathological evaluation even if the surgical resection is standard.
4. With lymph node metastasis, postoperative adjuvant chemotherapy is usually required. The more positive lymph nodes, the worse the prognosis.
If there is no lymph node metastasis and no distant metastasis is found, colon cancer generally belongs to stage II. Whether chemotherapy is needed depends on other factors, such as the depth of the tumor, the presence of nerve, vascular and lymphatic invasion, and MSI characteristics.
The number of negative lymph nodes, or the positive ratio, also has some assessment value.
5. Different locations of lymph nodes with metastasis have different prognosis
Lymph nodes with metastasis in distant lesions usually have a relatively poor prognosis. Lymph node metastasis in places beyond the resection range criteria is generally considered as distant metastasis. When available, the lymph nodes within the resection range can be grouped and the sites marked for further examination, and this part of the work requires the personal participation of the attending physician to be accurate.
6.Lymph node metastasis does not mean that it is incurable, and no lymph node metastasis does not mean that you can rest in peace
Some gastric cancers with lymph node metastasis and a large proportion of colorectal cancers can obtain better long-term results after standardized adjuvant treatment and careful regular review.
Without lymph node metastasis, there may also be distant metastasis by blood route, and regular checkups are needed to decide adjuvant treatment and review plan according to the condition.
Behind the pathology report
A pathology report requires the involvement of many people, including specimen processing, production staining, pathologist reading, and possibly additional sections or immunohistochemistry examinations. High-quality pathology evaluation requires a concerted effort by all.
In order to obtain accurate pathology results, surgeons need to pay attention to the handling of specimens after surgery. It is important to fix the specimen in a timely manner, which is especially important for postoperative immunohistochemical examination. After pretreatment of the specimen, for example, applying sutures and dyes to mark cut edges and key examination sites. Communication with pathology department from time to time will also promote each other and improve the quality of surgery and pathological examination.