Underlining the complexity of the structural and chemical characteristics of ectopic calcifications in breast tissues through FE-SEM and μFTIR spectroscopy

Abstract

International audienceBreast calcifications, defined as calcium deposits within breast tissue, can arise from a vast number of aetiologies. Diffuse or scattered distribution is typically seen in benign entities. Approximately 95% of all Ductal carcinoma-in-situ, which represents 25–30% of all reported breast cancers are diagnosed because of mammographically detected microcalcifications. In this investigation dedicated to breast calcifications, we assessed at the micrometer scale their chemical nature through last generation micro-Fourier transform Infrared microspectroscopy and their structural characteristics through last generation field emission scanning electron microscopy. Several striking results have been obtained. Heavily mineralized deposits seem to be the result of the agglomeration of micrometer scale spherules and for the first time, we show that micrometer scale spherules display very different internal structure. Moreover, while Ca phosphate apatite and calcium oxalate dihydrate are the two chemical phases usually reported, we underline the presence of a third chemical phase namely amorphous carbonated calcium phosphate. In the case of duct carcinoma in situ (DCIS), the chemical composition as well as the carbonate level are very inhomogeneous even inside micrometer scale breast calcifications. Moreover, for some samples related to DCIS, special features at the micrometer scale seem to be related to this pathology because they were not found for the other pathologies

Elemental vs. phase composition of breast calcifications

“…The chemical composition within breast calcifications has been found to be very inhomogenous 15 , hence an area measurement over the whole cut surface of a calcification is an attractive option for measuring the average composition. However, as a result of fragmentation by the microtome blade, the calcification surface is not smooth and perpendicular to the beam.…”

“…Microstructure of other pathological calcifications has also been shown to have potential for determining aetiology 14 . Breast calcifications also exhibit microstructural variations, such as a spherulitic structure that appears be related to malignancy 15 .…”

Correlative imaging reveals physiochemical heterogeneity of microcalcifications in human breast carcinomas

“…To date, the majority of research focusing on materials properties of MCs in breast tissue, has been performed using either dissected mineral(Büsing et al, 1981; Frappart et al, 1986, 1984; Hassler, 1969) or otherwise fixed or dehydrated tissue samples(Ahmed, 1975; Baker et al, 2010; Ben Lakhdar et al, 2016; Haka et al, 2002; Poggi et al, 1998; Scimeca et al, 2014; Scott et al, 2017, 2016). These sample preparation techniques can often introduce artifacts and make interpretation of mineral-matrix relationships difficult.…”

Raman opportunities in the field of pathological calcifications

“…In the following paragraphs a selection of investigations performed on pathological calcifications developed in breast [102][103][104][105][106][107][108][109][110][111][112][113], kidney , gallbladder [140][141][142][143][144][145][146][147][148][149], prostate [150][151][152][153][154][155][156][157][158][159][160][161], skin [162][163][164][165][166][167][168], testicular microlithiasis [169][170][171][172][173][174][175][176]…”