Affiliation:
1. Division of Cancer and Stem Cells School of Medicine, The University of Nottingham Nottingham UK
2. Department of Histology and Cell Biology, Faculty of Medicine Suez Canal University Ismailia Egypt
3. Nottingham Breast Cancer Research Centre Biodiscovery Institute, University of Nottingham Nottingham UK
4. School of Veterinary Medicine and Sciences, University of Nottingham Nottingham UK
5. Department of Pharmacology Weill Cornell Medicine New York NY USA
Abstract
BackgroundEncapsulated papillary carcinoma (EPC) is surrounded by a thick fibrous capsule‐like structure, which is interpreted as a thickened basement membrane (BM). This study aimed to describe the geometric characteristics of the EPC capsule and to refine whether it is an expansion of the BM or a stromal reactive process.Material and MethodsIn all, 100 cases were divided into four groups: EPC, ductal carcinoma in situ (DCIS), normal breast tissue and invasive tumours, with an additional encapsulated papillary thyroid carcinoma (EPTC) control group. Representative slides from each case were stained with picrosirius red (PSR) stain and examined using polarised microscopy. Images were analysed using ImageJ, CT‐FIRE, and Curve align image analysis programmes.ResultsCompared to the normal and DCIS BM, the EPC group showed a significant increase of collagen fibre width, straightness, and density, and a decrease of fibre length. The EPC capsule showed less alignment of fibres with a more perpendicular arrangement, and it was enriched with disorganised collagen type I (stromal collagen) fibres. Compared to other groups, the EPC capsule showed significant variation in the thickness, evenness, distribution of collagen fibres, and significant intracapsular heterogeneity. Compared to BM‐like material in the invasive group, the EPC capsule showed a higher density of collagen fibres with longer, straighter, and more aligned fibres, but there was no difference in the distribution of both collagen types I and III. Conversely, compared to EPTC, there were no differences between both EPC and EPTC capsules except that the fibres in the EPC capsule were straighter. Although differences between normal ducts and lobules and DCIS BM collagen fibre density, straightness, orientation, and alignment were detected, both were significantly different from EPC capsule.ConclusionThis study provided evidence that the EPC capsule is a reactive process rather than a thickened native BM characteristic of normal and in situ lesions, which provides further evidence that EPC is an indolent invasive carcinoma based on capsule characteristics.
Subject
General Medicine,Histology,Pathology and Forensic Medicine