Ultrasound evaluation of subcentimeter suspicious breast lesions: Correlation with histopathological findings and...

Mammography is the routine screening modality for breast cancer detection, however has limitations in dense breast parenchyma and with small lesion size. In these cases, Ultrasound has the potential for early disease detection with lesion size even small than a centimeter, improving patient outcome Primary aim is to evaluate potential of ultrasound imaging in characterizing suspicious sub-centimeter solid breast lesions by using BIRADS lexicon descriptors and correlate with histopathology. Secondary aim is to evaluate differences in sonographic appearance of different molecular subtypes of invasive sub centimeter malignancy.

In this retrospective study sub-centimeter solid lesions diagnosed as BIRADS IV-V, between 2020 to 2023 were included at Dow Institute of Radiology, Karachi, Pakistan. Lesion shape, margins, posterior features, orientation, vascularity and calcifications were reviewed from database. Univariate and multivariable binary logistic regression analysis performed to determine significant malignant findings on ultrasonography. Morphological features specific to molecular subtypes was assessed. A p-value of ≤ 0.05 was used to report statistical significance.Differences in sonographic appearance of molecular subtypes of invasive malignancy were seen in 90 sub-centimeter lesions.

Out of 90 lesions, 51 were malignant, and 39 were benign. On multivariable analyses, irregular shape, hypoechoic echotexture and not parallel orientation were significant features to differentiate between benign and malignant disease. No meaningful difference in sonographic appearance of molecular subtypes was observed in sub centimeter lesions.

Ultrasound is a beneficial modality for detection of sub-centimeter breast lesions, allowing appropriate BIRADS categorization. With decreasing lesion size, morphological characterization becomes difficult and needs careful evaluation. Irregular shape and not parallel orientation were the predictive sonographic signs of malignancy in sub-centimeter lesions.