Marcus and Welling improved a method to study early phases of breast cancer development ( 6- 8). The relation between breast cancer and surrounding normal tissue was further studied in 1939 by Ingleby and Holly ( 5). Specifically in 1973, Wellings and Jensen analyzed cases of in situ and invasive ductal and lobular carcinomas, leading to the proposal that most breast carcinomas arise in the TDLU ( 4). Subsequently, several studies based on LS were performed leading to the hypothesis that breast cancer originate mainly from the terminal ductular-lobular unit (TDLU) ( 4). The first use of LSs in breast pathology was reported by Cheatle at the beginning of the 20 th century ( 1- 3), who aimed to study the relation between breast cancer and the surrounding tissue. The aim of the present paper is to review the basis of applications of LS, their current use in breast pathology, and to provide an overview on the history and applications of this technique. Tissue obtained by LS encompasses not only the lesions, but also the surrounding tissue, the resection margins and allows radiological-pathological correlation useful to a better understanding of the diseases.

Large sections (synonim: macrosections, large format sections) (LSs) consist of an entire histological section of the organ under investigation. Keywords: Large section (LS) histology breast cancer carcinoma in situ invasive carcinoma resection margin tumor extent (TE) tumor multifocality (TM) The aim of the present paper is to review the value of LS in breast pathology. In addition, LSs play an important role in cases treated with neo-adjuvant (NAD) chemotherapy, as they are useful to better evaluate the residual cancer burden and the degree of tumour regression. In the multidisciplinary era, LSs allow the correlations between radiological and pathological data. The presence and extension of in situ carcinoma is more completely observed, overcoming the difficulties of gross inspection at naked eye. LS in breast pathology is useful to a proper definition of stage disease, tumor size (TS), tumor extent (TE), tumor multifocality (TM) and resection margins. LSs are also employed in surgical pathology of various organs, among which breast is comprised. Immunohistochemistry or molecular studies are feasible by selecting areas of interest from LS and cutting them to obtain small conventional blocks.

It has been demonstrated that costs do not differ from conventional blocking and the turn-around-time could be no longer than 24 hours. Abstract: Large sections (LSs), (synomim: macrosections), are used in daily routine practice of breast pathology to better investigate the disease and to allow a thorough diagnosis.

Pathology cancer