The Lobar Concept in Imaging the Complex Morphology of Breast Carcinoma

Abstract

Breast carcinoma is a heterogeneous disease involving most often the structures of a single breast lobe that carries genetic aberrations and is more sensitive to oncogenic stimuli compared to the healthy lobes of the same breast. The disease begins during the embryonic development of the breast lobes and persists until the patients’ death or until the sick lobe or the tumor that originated in it has been surgically removed or destroyed with irradiation or drugs. The malignant structures may occupy a single focus or multiple foci within the sick lobe or may be spread over large parts of the lobe. While the subgross morphology of the unifocal disease is relatively simple, multifocal and diffuse cancers exhibit complex morphology that needs multiparameter characterization (assessing tumor size, disease extent, lesion focality, and heterogeneity). Proper preoperative radiological assessment of the complexity of the breast lesions is very important because the subgross parameters carry prognostic information and are related to molecular features of the tumor. As such, they guide both the surgical and oncological therapeutic decisions. Multimodality radiology is very accurate in this setting, but histopathology, especially if using large-format slides, is still a more sensitive method. The best results are achieved with detailed and systematic radiological–pathological correlation, especially if both radiologists and pathologists are aware of the fact that the structures of the cancer are most often clustered to the area of the sick lobe and explore the advantages of the lobar approach as the method of choice in diagnosing early breast carcinoma.