title: Second harmonic generation microscopy is a novel technique for differential diagnosis of breast fibroepithelial lesions.
abstract: Breast fibroepithelial lesions, including fibroadenomas and phyllodes tumours, are commonly encountered in clinical practice. As histological differences between these two related entities may be subtle, resulting in a challenging differential diagnosis, pathological techniques to assist the differential diagnosis of these two entities are of high interest. An accurate diagnosis at biopsy is important given corresponding implications for clinical decision-making including surgical extent and monitoring. Second harmonic generation (SHG) microscopy is a recently developed optical imaging technique capable of robust, powerful and unbiased label-free direct detection of collagen fibril structure in tissue without the use of antibodies. We constructed tissue microarrays emulating limited materials on biopsy to investigate quantitative collagen signal in fibroepithelial lesions using SHG microscopy. Archived formalin-fixed paraffin-embedded materials of 47 fibroepithelial lesions (14 fibroadenomas and 33 phyllodes tumours) were evaluated. Higher collagen signal on SHG microscopy was observed in fibroadenomas than phyllodes tumours on SHG imaging (p<0.001, area under the curve 0.859). At an automated threshold (2.5 million positive pixels), the sensitivity and specificity of the SHG microscopy for fibroadenoma classification was 71.4% and 84.4%, respectively. To corroborate these findings, we performed immunohistochemistry on tissue array sections using collagen I and III primary antibodies. Both collagen I and III immunohistochemical expressions were also significantly higher in fibroadenomas than in phyllodes tumours (p<0.001). In conclusion, label-free collagen quantitation on SHG microscopy is a novel imaging approach that can aid the differential diagnosis of fibroepithelial lesions.
authors.affiliation: Institute of Bioengineering and Nanotechnology, Singapore.
authors.forename: Wai Jin
authors.initials: WJ
authors.lastname: Tan
authors.affiliation: Institute of Bioengineering and Nanotechnology, Singapore.
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
authors.affiliation: Institute of Bioengineering and Nanotechnology, Singapore.
authors.forename: Shuoyu
authors.initials: S
authors.lastname: Xu
authors.affiliation: Department of Pathology, Singapore General Hospital, Singapore.
authors.forename: Aye Aye
authors.initials: AA
authors.lastname: Thike
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Boon Huat
authors.initials: BH
authors.lastname: Bay
authors.affiliation: Institute of Bioengineering and Nanotechnology, Singapore Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore Mechanobiology Institute, National University of Singapore, Singapore Singapore-MIT Alliance for Research and Technology, Singapore.
authors.forename: Hanry
authors.initials: H
authors.lastname: Yu
authors.affiliation: Institute of Bioengineering and Nanotechnology, Singapore.
authors.forename: Min-Han
authors.initials: MH
authors.lastname: Tan
authors.affiliation: Department of Pathology, Singapore General Hospital, Singapore Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore Duke-NUS Graduate Medical School, Singapore.
authors.forename: Puay Hoon
authors.initials: PH
authors.lastname: Tan
mesh_terms: D001706:Biopsy; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D003094:Collagen / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D018226:Fibroadenoma / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008853:Microscopy / Q000379:methods*; D003557:Phyllodes Tumor / Q000378:metabolism / Q000473:pathology*; D046888:Tissue Array Analysis
chemical_list: D003094:Collagen
keywords: BREAST PATHOLOGY; IMAGE ANALYSIS; IMMUNOHISTOCHEMISTRY