The Many Facesof Invasive Lobular Carcinoma: A Multimodality DescriptiveApproach

Abstract Background: Invasive lobular carcinoma (ILC) of the breast is the second mostcommon histological type of breast malignancy. Its mammographic appearance canbe subtle or even occult, leading to a higher rate of delayed or missed diagnosis. Theuse of ultrasound and contrast enhanced mam-mography (CEM) can greatly improvethe diagnostic accuracy and estimation of disease extent. Aim of Study: Review the appearance of invasive lobular-carcinoma (ILC) on multimodality imaging using acase-based approach to highlight the pearls and pitfalls of making this challenging diagnosis. Patients and Methods: This prospective cross-sectional study included all consecutive female patients with patholog-ically proven ILC referred to the Radiology Department from January 2018 to July 2022 who underwent digital mammog-raphy, breas tultrasound and contrast enhanced spectral mammography. Results: A total of 150 patients with pathologically proven breast invasive lobular carcinoma were included. Solid masses whether single or multiple were the most common finding in digital mammography, ultrasound and contrast enhanced spectral mammography representing 33.3, 67.3 and 35.3% respectively. The second most form form of presentation in mammography was breast asymmetry representing 30.7% of the total number of the cases, where in ultrasound altered echogenicity/focal adenotic tissue was the second most com-mon presentation. Non mass enhancement in its 3 different forms (segmental, regional or global) accounted for the second highest number of cases in the CESM. Conclusion: A frank mass is the commonest form of presentation of ILC in the used radiological imaging tech-niques, whether showing as a speculated hyperdense mass in digital mammography or an ill defined hypoechoic solid lesion in ultrasound. Asymmetry represented the second most com-mon form in the mammographic films. In cases with subtle mammographic or sonographic findings such focal architectural distortion of focal adenotic tissue, CESM enhanced the diag-nosis, expanding the role of CESM as an adjunct tool for proper diagnosis and hence management.