(A) Types of pathology
Q1: What is intraepithelial neoplasia of the colorectum? What is intra-mucosal carcinoma of the colorectum? What is the difference between neoplasm and cancer?
A1: A lesion with heavy heterogeneous epithelial hyperplasia and the depth of infiltration cannot be judged is called high-grade intraepithelial neoplasia, and if cancerous tissue infiltrates the lamina propria, it is called intramucosal carcinoma.
Note: According to the current level of understanding of research, we generally believe that the occurrence and development of non-hereditary colorectal cancer is a process that spans roughly 5-10 years from normal mucosa, atypical hyperplasia, adenoma to adenocarcinoma].
Q2: What is early colorectal cancer?
A2: Cancer cells penetrating the mucosal muscle layer of the colorectum and infiltrating into the submucosa without involving the intrinsic muscle layer, regardless of whether there is lymph node metastasis, is called early colorectal cancer (pT1).
The new specification recommends measuring and grading the depth of submucosal infiltration in early colorectal cancer, i.e. SM1 (submucosal infiltration depth ≤1mm) and SM2 (submucosal infiltration depth >1mm).
Note: The intestinal wall of the colorectum is very thin. A recent data set of human specimens measured by Dr. Jun Zhou showed that the thickness of the intestinal wall of the ascending colon in normal adults is between 0.43 mm and 0.77 mm, and if there is spasm in the intestinal wall, the thickness of the intestinal wall is around 1 to 2 mm, and the wall of the diseased intestine is even thicker. At present, the clinical application of colorectal microscopy for submucosal early tumor resection is becoming more and more mature and widespread.
To give you an example to understand the development of endoscopic removal of early colorectal cancer or colorectal lesions: the Endoscopy Center of Zhongshan Hospital of Fudan University has very mature technology and very successful experience, and the famous Mayo Clinic-Mayo Clinic in the U.S. has sent people for advanced training].
Q3: What is the general type of progressive colorectal cancer?
A3: When colorectal cancer develops further to the progressive stage from the early stage when it is difficult to detect and distinguish from other benign lesions, the morphology of these tumors that can be seen by the human naked eye, i.e. the general specimen of the tumor, is mainly divided into three types.
(1) Augmentation type. Any tumor whose main body protrudes into the intestinal lumen belongs to this type.
(2) Ulcerated type. Any tumor that forms an ulcer deep to or through the muscle layer is of this type.
(3) Infiltrative type. The tumor infiltrates diffusely into all layers of the intestinal wall, causing local thickening of the intestinal wall, but there is often no obvious ulcer or bulge on the surface.
Q4: What is the histological type of colorectal cancer?
A4: In order to distinguish what kind of tumor a large mass is, pathologists or pathologists use light microscopes or even more modern and advanced microscopes to distinguish the pathological types of tumors at the tissue or even cellular level. The histological typing of colorectal cancer is as follows.
(1) Adenocarcinoma;
(2) Mucinous adenocarcinoma;
(3) cessation cell carcinoma;
(4) squamous carcinoma;
(5) Adenosquamous carcinoma;
(6) Medullary carcinoma;
(7) Undifferentiated carcinoma;
(8) Other;
(9) Carcinoma, type cannot be determined.
Note: Early assessment of the effectiveness of colorectal treatment relied on this histologic type, and it has been used to this day, even with precision medicine applications, histologic type has always been one of the very important classification methods that are indispensable.
Dr. Jun Zhou explained that precision medicine is also known as individualized treatment: according to each patient’s own situation especially the tumor type, more emphasis is now placed on more precise and detailed medical achievements such as molecular level and genetic level to treat each patient].
Q5: What is the histological grading of colorectal cancer?
A5: Histologic grading is the classification of colorectal cancer into different levels of malignancy according to what is seen histologically, so that we can better understand that the malignancy of the same tumor varies from mild to severe. The histological grading criteria of colorectal cancer are shown in Table 1.
Table 1 Histological grading criteria of colorectal cancer (according to WHO 2010 edition)
Criteria
Degree of differentiation
Numerical grading
a
Descriptive grading
>95% glandular duct formation
Highly differentiated
1
Low grade
50%-95% glandular duct formation
Intermediate differentiation
2
Low grade
0-49% glandular duct formation
Low differentiation
3
High level
High level microsatellite instability b
unequal
unequal
Low grade
Note: a, Undifferentiated carcinoma (grade 4) This category refers to the absence of glandular duct formation, mucus production, neuroendocrine
squamous or sarcomatoid differentiation; b, MSI-H.
*The above grading criteria are specific to adenocarcinoma.
(II) Content of pathology report
Q6: What are the contents and requirements of the pathology report for biopsy specimens?
A6: The content of the new version of the report hopes that hospitals and medical-related units that are in a position to do so can take advantage of the development of science and technology, and at the same time, the country strongly encourages domestic national innovative industries to develop equipment that is relatively inexpensive, expecting to provide more domestic patients with more affordable services relative to domestic ones. The requirements are as follows.
(1) Basic patient information and delivery information.
(2) If there is intraepithelial neoplasia (heterogeneous hyperplasia), report the grading.
(3) In case of invasive carcinoma, differentiate the histological type.
(4) Detection of mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, PMS2) and Ki-67 expression is recommended when colorectal cancer is identified.
Clinicians should be aware that biopsy pathology cannot fully determine the depth of infiltration due to the limitations of biopsy sampling depth, so the tumor tissue may be high-grade intraepithelial neoplasia or intramucosal carcinoma confined to the mucosa.
Note: With the further development of science, new examination techniques are transformed into medical testing instruments to serve patients. Of course, the cost of the test will increase accordingly, after all, pharmaceutical companies have invested a lot in developing these devices to earn a little.
Dr. Zhou Jun is so think through this thing, the same examination, if in the western developed countries to do this set of tests cost a lot more than the domestic, we think we are very cheap. There may be friends looking at this disease 10 years ago to see this disease and 10 years later to see this disease spend different money.
This… In fact, the cost of the test can still be as low as it was 10 years ago, only friend, you enjoy the medical resources will be worse than other patients. The reason is that modern medicine is more developed, the means of detection is more abundant, and the money spent is more powerful. The more advanced medicine is, the more doctors dare not handle the condition at will without examination, because they have to be responsible for both the patient and themselves. It may be too simple to understand it that way, so I won’t elaborate on it and leave it for you to think about.
Q7: What are the contents and requirements of the pathology report for endoscopically resected adenoma specimens?
A7: It should be well understood by looking at the following.
(1) Basic information of the patient and information of the sending examination.
(2) The size of the tumor.
(3) Grading of intraepithelial neoplasia (heterogeneous hyperplasia).
(4) In case of infiltrative carcinoma, report the histological staging, grading, depth of infiltration, cutting edge condition, vascular invasion, and mismatch repair (MMR) protein (MLH1, MSH2, MSH6, PMS2) expression of the cancer tissue.
In cases of pT1, 3 and 4 grade differentiation, vascular invasion, and positive cut margins, additional surgical resection should be performed clinically to expand the scope of resection. In other cases, enteroscopic resection is sufficient, but regular postoperative follow-up is required.
1 Histologic features with a favorable prognosis include: grade 1 or 2 differentiation, absence of vascular, lymphovascular infiltration, and “lymphoid infiltration.
lymphovascular infiltration, and “negative margins”.
2 Histologic features with a poor prognosis include: grade 3 or 4 differentiation, vascular, lymphatic infiltration, and “negative margins.
lymphovascular infiltration, and “positive cut margins.
3 Positive margins are defined as tumor less than 1 mm from the margin or cancer cells visible at the edge of the scalpel.
Q8: What are the main contents and requirements of the pathology report of surgical specimens?
A9: The main contents and main requirements are as follows.
(1) Basic information of the patient and information of the sending examination.
(2) General condition: tumor size, general type, depth of infiltration seen by the naked eye, length of both ends of resected intestinal canal from the distal and proximal ends of the tumor.
(3) Degree of tumor differentiation (tumor staging and grading).
(4) Depth of tumor infiltration (T-stage) (T-stage or ypT is based on viable tumor cells; mucus lakes without cells within the specimen after neoadjuvant therapy are not considered as tumor residual).
(5) Number of lymph nodes detected and number of positive lymph nodes (N stage); and extra-lymph node tumor implantation (ENTD, Extra Nodal Tumor Deposit), which refers to irregular tumor solid nodules deposited in peri-colorectal adipose tissue away from the primary tumor margin, without histologic evidence of residual lymph nodes, but distributed along the lymphatic drainage pathway of the tumor.
(6) The status of the proximal cutaneous margin and distal cutaneous margin.
(7) It is recommended to report the status of the tethered/peri-annular margins (if the tumor is very close to the margins, the distance between the tumor and the margins should be measured and reported under the microscope, and the tumor within 1mm from the margins should be reported as positive for the margins).
Note: Dr. Zhou Jun has also done some research in this area and has sent out “One Question, One Answer, Easy to Understand] Ten Questions on Preoperative MRI Staging of Rectal Cancer” to help you better understand why the pathology report should have these contents, of course the following plus Q10 is the complete version.
All of these contents are for the doctors of various related departments to better detect, diagnose, evaluate, treat and prognosticate patients’ diseases and can better serve patients. Some friends may think that write so much, and I can not read. Dr. Zhou Jun so understand to see can solve your a confusion not: often some patients say pay no results, then give a result, but can not read, in fact, this result is convenient for your next visit or to another city, another hospital to see a doctor, so that other doctors to see you can be more comprehensive understanding of your condition, so that the doctor can better serve you.
If you have the medical knowledge to understand, we will all be very happy and do not need too much explanation; but if the understanding is wrong, the most worried to cause you a psychological burden. Therefore, if you have a hospital report that you can’t understand, bring all the information to your next visit and let the doctor help you.
Q9: How to evaluate the efficacy of neoadjuvant radiation (or, and) chemotherapy?
A9: The role of neoadjuvant therapy in the preoperative period is now receiving more and more attention. The contents are as follows.
Grade 0
Complete response
No tumor residual
Grade 1
Moderate response
Small amount of tumor residue
Grade 2
Low response
Most tumor residue
Grade 3
No reaction
Q10: What are the other contents and requirements of the pathology report for a complete surgical specimen?
A10: Important elements are also needed to predict prognosis, etc.
(1) Vascular invasion (V for vascular, V1 for microscopic vascular infiltration, V2 for naked eye vascular infiltration, and L for lymphatic vessels). It is recommended to try to distinguish between vascular and lymphatic infiltrations.
(2) Nerve invasion.
(3) Mismatch repair (MMR) protein (MLH1, MSH2, MSH6, PMS2) expression. Optional testing for gene status and methylation status of mismatch repair proteins is recommended.
(4) When recurrent or metastatic colorectal cancer is identified, it is recommended to detect
K-ras, N-ras, BRAF gene status. They can be determined from biopsy specimens if surgical resection specimens are not available.
The prerequisite for a complete pathology report is a detailed pathology request form completed by the clinician, detailing the surgical findings and relevant clinical ancillary findings and clearly labeling the lymph nodes. Mutual communication, trust and cooperation between clinicians and pathologists are the basis for establishing correct staging and guiding clinical treatment.