The main purpose of the study of precancerous lesions in breast cancer is to elucidate the developmental pattern of breast cancer, to determine the significance of various types of precancerous lesions, and to carry out blocking treatment to prevent the occurrence of breast cancer or to achieve the purpose of early diagnosis and early treatment.
Broadly speaking, any general proliferative lesions can be called precancerous lesions, but such lesions are widely present and have a low chance of becoming cancerous; therefore, they are generally not treated as precancerous lesions. However, for lesions with atypical hyperplasia, it has a higher chance of cancer, therefore, these lesions are the focus of our research and the central concern of physicians. As for the study of the relationship between cystic hyperplasia of the breast and breast cancer, a lot of work has been done over the years, and many authors have conducted studies, for example, someone followed up eight types of cystic hyperplasia of the breast, with all 1289 cases.
These include.
(1) solid hyperplasia in 39 cases (3.0%)
(2) papillary hyperplasia in 108 cases (8.3%)
(3) 92 cases of ductal adenopathy (7.1%)
(4) 258 cases of sweat gland hyperplasia (20%)
(5) 78 cases of adenopathy (6.0%)
(6) Distal duct hyperplasia 155 cases (12%)
(7) Periductal inflammation in 108 cases (8.4%)
(8) Simple cysts in 45 cases (34.9%).
In a group of 284 cases with local excision only, there were 16 cases of solid hyperplasia with an average follow-up of 4 years, of which 1 case developed into cancer, with a cancer rate of 6.2%. The average follow-up was 1 year and 6 months in 52 cases of papillary hyperplasia. 2 cases developed cancer (3.8%), while the average follow-up was 13 years in 176 cases without hyperplasia, and the cancer rate was lower in those without hyperplasia. 284 cases were followed up for an average of 13 years, and the overall cancer rate was 2.43%.
The study showed that cystic hyperplasia of the breast is indeed a precancerous lesion.
Karpas observed 645 cases of breast disease, of which 226 were malignant and the remaining 419 were cystic hyperplasia, of which 110 (26%) had hyperplastic changes and 106 (25%) had microscopic changes. The percentage of those with adenopathy was 9%, those with sweat gland hyperplasia was 15%, and those with microscopic changes was 65%.
Many authors have reported that 56-80% of breast cancers are associated with cystic hyperplasia, and the rate of breast cystic disease developing into breast cancer is 3-4 times higher than that of the general population. The cancer rate is even higher in those with atypical hyperplasia.
Since there are so many cystic hyperplasia of the breast and the cancer rate varies among the various types of cystic disease, further classification of these hyperplastic lesions into grades (or levels) would be of some help in the clinical management of patients or in the follow-up of patients, therefore, we suggest whether the altered classification of BIN (Breast intraepithelial reoplasm) could be used to reveal the relationship between them, with specific classification, which is proposed as follows.
BIN: Grade I: including simple cysts, breast adenopathy, and myoepithelial hyperplasia
BIN: Grade II: including ductal epithelial hyperplasia, small solid hyperplasia
BIN: Grade III: including ductal epithelial papillary hyperplasia, sweat gland hyperplasia and papillary hyperplasia, sclerosing adenopathy, atypical hyperplasia of various lesions
BIN: Grade IV: including intraductal carcinoma, lobular carcinoma in situ, etc.
This grading, for clinical reference, generally speaking, BIN I, does not require clinical treatment, BIN II should be followed up more loosely, BIN III should be followed up closely for regular checkups, and BIN IV, aggressive treatment should be used.
Cases that are easily misdiagnosed by frozen section
1. Breast cancer, which is the most common frozen section, especially in oncology specialty hospitals. We have two cases of breast fibroid tumors that have been radically resected without freezing, as well as cases of plasmacytoid mastitis that have been radically resected without freezing.
2, cystic hyperplasia of the breast, especially ductal epithelial papillary hyperplasia of breast cystic disease, this lesion has many names such as papillomatosis, mammary epithelial hyperplasia, cystic hyperplasia of the breast with sweat gland hyperplasia, etc.. It is often the paraneoplastic epithelium of breast cancer. When encountering this condition, we should pay attention to take more material to avoid missing the diagnosis, which is usually without heterogeneity or mild heterogeneity, without necrosis and without infiltration different from papillary carcinoma.
3.Sclerosing breast adenopathy: It is often accompanied by sclerosing adenopathy in the background of breast cystic disease hyperplasia, which is composed of hyperplastic ducts or ductal vesicles and fibroblasts with fibrosis, often with focal distribution, and the hyperplastic epithelium is solid or striated, surrounded or extruded by dense connective tissue, coolly infiltrated but well differentiated cells.
The lesions are often surrounded by lobular or tubular structures, without necrosis, hemorrhage, nuclear division, tumor thrombus in blood vessels or lymphatic vessels, and no nerve involvement or adipose tissue, and myoepithelial hyperplasia is common. Unlike hard carcinoma, it often involves adipose tissue, generally lacks residual lobular structure, myoepithelium is difficult to find, and tumor cells are very small.
4.Mammary adenopathy tumor: This is a kind of lesion with hyperplasia of both lobules and interstitium, but the hyperplasia of the lobules is especially prominent, resulting in hypertrophy of the lobules and their fusion with each other, with most of the lobular structures disappearing, and the fused lobules are dense and irregular in shape, with hyperplasia of the glandular epithelial cells, but without heterogeneity, with little interstitium and often with envelope. It is also known as Flord adonosis, which is essentially a manifestation of adenopathy, and should be distinguished from ductal carcinoma on frozen section.
5. Plasmacytoid mastitis: relatively rare, but not very rare, with clinical manifestations of nipple retraction, orange peel-like, hard lumps of breast with indistinct margins. The histology is a large number of mature plasma swellings in the form of sheets or cords, while numerous lymphocytes, focal epithelioid cells, multinucleated giant cells and histiocytes can also be seen, and the glandular ducts are dilated. It is easily confused with undifferentiated carcinoma when the frozen section is poor.
6.Fat necrosis of the breast: often caused by trauma, inflammation or surgery, clinically it can be seen as a hard, fixed breast mass with unclear borders. Histologically, the adipose tissue remains or disappears, and the necrotic adipocytes fuse with each other to form large vacuoles, which are infiltrated with numerous lymphocytes, plasma cells and lipophagic foam cells. Frozen section should be distinguished from lipid-rich breast cancer.
7.Ductal carcinoma of breast: also known as highly differentiated adenocarcinoma, it is relatively rare, with well-differentiated cells, uniform size and morphology, and the cells are rectangular or flattened, surrounded by small ducts scattered in connective tissue, often involving blood vessels, lymphatic vessels or nerve tissue.