Triple negative breast cancer originating from a cystic lesion

Abstract

According to the World Health Organization, 2.3 million women worldwide were diagnosed with breast cancer in the year 20201 . Triple negative breast cancer, which lacks the expression of hormone receptors and HER-2, accounted for 12% of breast tumors diagnosed in the United States of America between 2012 and 20162 . In addition to the known risk factors for the development of breast cancer, specifically in this type of neoplasm, there are other risk factors, such as age below 40 years, mutation in BRCA1/2 genes and African American ethnicity2,3. The diagnosis of invasive breast carcinoma is made through associated clinical and radiological characteristics and confirmation by cytopathological or histopathological biopsy⁴. Considering the classification of the American College of Radiology (BI-RADS®), simple cysts are classified, in general, as a benign finding, that is BI-RADS 2. However, they can be evaluated as suspicious or highly suspicious (BI-RADS 4 or 5) when presenting hemorrhagic content, signs of wall thickening, irregular septa, associated solid lesion, irregular vascularization, among other radiological findings related to malignancy4-6. Semiology is important to identify a change in the biological behavior of a simple cyst. Cystic lesions characterized as benign, but showing alterations, such as increased size and suspicious radiological characteristics, should be investigated5,6. The objective of this work was to document the case of a young pregnant patient with triple negative breast cancer, diagnosed in the wall of a lesion, previously characterized as a simple cyst.