CLINICAL PATHOLOGICAL AND MAMMOGRAPHIC CORRELATION OF INVASIVE LOBULAR CARCINOMA IN THE CONTEXT OF BREAST DENSITY

Introduction It has been proposed that areas of increased breast density, as defined mammographically, might represent a non-obligate precursor of breast cancer. However, the association between breast density, invasive lobular carcinoma (ILC) and that of its precursor lesions, lobular carcinoma in situ /atypical lobular hyperplasia (LCIS/ALH), has not been investigated yet. We also aimed to investigate whether specific pathological features contribute with the mammographic presentation of ILC (e.g., speculated vs occult). Methods The radiology and pathology of 147 patients were reviewed for radiological-pathological correlation. Immunohisto-chemistry was performed on tissue microarrays. Results This analysis revealed that women with dense breasts and ILC were more likely to be young, to have mammographically occult tumours and to have an increased frequency and extent of LCIS/ALH. The following features were also significantly associated with the mammographic presentation of ILC: the extent of lymphocytic infiltrate, the appearance of the tumour stroma and the expression of cyclin E. This study addressed for the first time the mammographic appearance of ILC in the context of the surrounding non-neoplastic breast parenchyma.