gynecology and obstetrics
Breast Cancer
Pathology of Breast Cancer
Most breast cancers are epithelial tumors (carcinomas) that develop from cells lining ducts or lobules; nonepithelial cancers of the supporting stroma (eg, angiosarcoma, primary stromal sarcomas, phyllodes tumor) are less common. Epithelial cancers are divided into carcinoma in situ and invasive cancer. Carcinoma in situis proliferation of cancer cells within ducts or lobules but without invasion of stromal tissue. There are 2 types: DCIS refers to neoplastic epithelial lesions that are confined to the breast ducts; lesions may have varying histology and malignant potential. It is usually detected only by mammography. It may involve a small or wide area of the breast; if a wide area is involved, microscopic invasive foci may develop over time. DCIS accounts for approximately 20% of breast cancers ( References ). Two randomized studies of DCIS comparing the addition of radiation and LCIS is often multifocal and is bilateral in approximately 20 to 60% of cases ( References ). There are 2 types: classic and pleomorphic (cells are larger and more atypical). Classic LCIS is not malignant but increases risk of developing invasive carcinoma in either breast. This nonpalpable lesion is usually suspected based on calcifications or a mass on mammography or ultrasonography and is diagnosed with biopsy. Pleomorphic LCIS behaves more like DCIS; it should be excised to negative margins. Paget Disease of the Breast None is primarily adenocarcinoma. Approximately 75% are infiltrating ductal histology and 10% of the remaining cases are infiltrating lobular ( References ). ) tumor ( References ); approximately 70% of all breast cancers are that are usually associated with a favorable prognosis include medullary, mucinous, cribriform, and tubular carcinomas ( References ). Mucinous carcinoma tends to develop in older women and be slow growing. Rare types that typically have a poor prognosis include metaplastic and inflammatory breast cancer.Inflammatory breast canceris a fast-growing, particularly aggressive, and often fatal cancer. Cancer cells block the lymphatic vessels in breast skin; as a result, the breast appears inflamed, and the skin appears thickened, resembling orange peel (peau d’orange). Usually, inflammatory breast cancer spreads to the lymph nodes in the armpit. The lymph nodes feel like hard lumps. However, often no mass is felt in the breast itself because this cancer is dispersed throughout the breast. 1.Giaquinto AN, Sung H, Miller KD, et al: Breast Cancer Statistics, 2022.CA Cancer J Clin72(6):524-541, 2022. doi:10.3322/caac.21754 2.Wapnir IL, Dignam JJ, Fisher B, et al: Long-term outcomes of invasive ipsilateral breast tumor recurrences after lumpectomy in NSABP B-17 and B-24 randomized clinical trials for DCIS.J Natl Cancer Inst103(6):478-488, 2011. doi:10.1093/jnci/djr027 3.Wen HY, Brogi E: Lobular Carcinoma In Situ.Surg Pathol Clin11(1):123-145, 2018. doi:10.1016/j.path.2017.09.009 4.American Cancer Society: Breast Cancer Facts & Figures. Accessed May 4, 2023 5.Anderson WF, Chatterjee N, Ershler WB, et al: Estrogen receptor breast cancer phenotypes in the Surveillance, Epidemiology, and End Results database. Breast Cancer Res Treat. 2002;76(1):27-36. doi:10.1023/a:1020299707510 6.Li Y, Yang D, Yin X, et al: Clinicopathological Characteristics and Breast Cancer-Specific Survival of Patients With Single Hormone Receptor-Positive Breast Cancer.JAMA Netw Open3(1):e1918160, 2020. doi:10.1001/jamanetworkopen.2019.18160 7.Howlader N, Altekruse SF, Li CI, et al: US incidence of breast cancer subtypes defined by joint hormone receptor and HER2 status.J Natl Cancer Inst106(5):dju055, 2014. Published 2014 Apr 28. doi:10.1093/jnci/dju055 8.National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program: Cancer Stat Facts: Female Breast Cancer Subtypes. Accessed May 4, 2023 