Correlation of Histopathology and Radiological Findings Among the Diverse Breast Lesions in a Tertiary Care Centre.

Introduction Breast lumps in any age group are addressed cautiously to exclude the possibility of breast cancer. The clinical approach to breast lumps involves the "triple test" for cancer screening. The triple test includes clinical examination, imaging (mammogram or ultrasonogram), and tissue sampling (fine needle aspiration cytology (FNAC) and core needle biopsy). These tests happen in a sequential process, and it is important that their findings support the final diagnosis for accurate management of the patient. Aims and objectives This study aims to determine the correlation between the histopathological and radiological findings among the various breast lesions and describe the spectrum of breast lesions received in our center. Methods This is a retrospective observational study for a period of three years, from January 2020 to December 2022. The study included 400 patients who had undergone ultrasonography or mammograms for breast lumps, FNAC, core needle biopsy, or surgical resection. The data collected was analyzed for concordance and discordance status. Results A total of 400 cases were reviewed. There were 238 (59.5%) histologically confirmed benign breast lesions and 162 (40.5%) malignant lesions with their corresponding BI-RADS (Breast Imaging Reporting and Data System) scores. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for the imaging modalities (ultrasonogram and mammogram) in diagnosing breast lesions were 95.06%, 94.96%, 92.77%, 96.58%, and 95%, respectively, which were comparable with other similar studies. The biological and immunohistochemical factors of all the invasive carcinomas were studied in detail. Conclusions Imaging modalities (ultrasonogram or mammogram) have good sensitivity and specificity in diagnosing breast lesions and can be reliably used as a preliminary test in breast lump evaluation. The BI-RADS score is a reliable indicator and can be considered for the effective follow-up or intervention of the breast lesion. In discordant cases, a repeated core needle biopsy or excision has to be recommended, as pathological diagnosis is the cornerstone of effective management. A good rapport between the surgeon, radiologist, and pathologist aids in effective feedback and learning for achieving diagnostic accuracy.

Shear jamming and fragility in fractal suspensions under confinement.

Under applied stress, the viscosity of many dense particulate suspensions increases drastically, a response known as discontinuous shear-thickening (DST). In some cases, the applied stress can even transform the suspension into a solid-like shear jammed state. Although shear jamming (SJ) has been probed for dense suspensions with particles having well-defined shapes, such a phenomenon for fractal objects has not been explored. Here, using rheology and in situ optical imaging, we study the flow behaviour of ultra-dilute fractal suspensions of multi-walled carbon nanotubes (MWCNT) under confinement. We show a direct transition from flowing to SJ state without a precursory DST in fractal suspensions at an onset volume fraction, ϕ ∼ 0.5%, significantly lower than that of conventional dense suspensions (ϕ ∼ 55%). The ultra-low concentration enables us to demonstrate the fragility and associated contact dynamics of the SJ state, which remain experimentally unexplored in suspensions. Furthermore, using a generalized Wyart-Cates model, we propose a generic phase diagram for fractal suspensions that captures the possibility of SJ without prior DST over a wide range of shear stress and volume fractions.

Bimodality and re-entrant behaviour in the hierarchical self-assembly of polymeric nanoparticles.

We show that a film of a suspension of polymer grafted nanoparticles on a liquid substrate can be employed to create two-dimensional nanostructures with a remarkable variation in the pattern length scales. The presented experiments also reveal the emergence of concentration-dependent bimodal patterns as well as re-entrant behaviour that involves length scales due to dewetting and compositional instabilities. The experimental observations are explained through a gradient dynamics model consisting of coupled evolution equations for the height of the suspension film and the concentration of polymer. Using a Flory-Huggins free energy functional for the polymer solution, we show in a linear stability analysis that the thin film undergoes dewetting and/or compositional instabilities depending on the concentration of the polymer in the solution. We argue that the formation via 'hierarchical self-assembly' of various functional nanostructures observed in different systems can be explained as resulting from such an interplay of instabilities.

Re-entrant behavior in dynamics of binary mixtures of soft hybrid nanocolloids and homopolymers.

We present results of measurements of temperature and wavevector dependent dynamics in binary mixtures of soft polymer grafted nanoparticles and linear homopolymers. We find evidence of melting of the dynamically arrested state of the soft nanocolloids with addition of linear polymers followed by a re-entrant slowing down of the dynamics with further increase in polymer density, depending on the size ratio, δ, of the polymers and the nanocolloids. For higher δ the re-entrant behavior is not observed, even for the highest added polymer density, explored here. Possible explanation of the observed dynamics in terms of the presence of a double-glass phase is provided.