GREY ZONE“ OF BREAST LESIONS WITH FOCUS ON INFILTRATING EPITHELIOSIS OF BREAST

Introduction: Breast cancer forms a heterogeneous group of lesions with variable clinical and morphological presentation. Breast cancer includes lesions showing borderline morphological and clinical features. Such lesions occur in the grey zone between benign and malignant lesions and their behaviour cannot be predicted clearly. Morphological classification of these lesions is very demanding, often biased and leading to various diagnoses that trigger over- or under-treatment of patients. In order to understand these lesions, we use the progressively developing molecular biology, the results of which may or may not be manifested in the estimation of the clinical behaviour of these lesions. Current State of Things: Malignant breast cancer is manifested by a wide range of differentiation or phenotypic diversity that is based on engagement of various pathological molecular signalling pathways. There are lesions that are characterized with ambiguous histological picture and show malignant histomorphological changes, but have a significantly limited metastatic potential. Infiltrating Epitheliosis: Infiltrating epitheliosis (IE) is a rare complex sclerosing lesion (CSL) of the breast characterized by infiltrating ducts immersed in a scleroelastotic stroma.