Imaging of radial scars on Digital Breast Tomosynthesis: a pictorial review.

Transcription

1 Imaging of radial scars on Digital Breast Tomosynthesis: a pictorial review. Poster No.: C-2114 Congress: ECR 2017 Type: Educational Exhibit Authors: E. Zanelli, I. Bednarova, A. Dallorto, A. Linda, C. Zuiani ; Udine, italia/it, Udine/IT Keywords: Breast, Mammography, Ultrasound, MR, Diagnostic procedure, Neoplasia, Developmental disease DOI: /ecr2017/C-2114 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 20

2 Learning objectives Goals: 1) to illustrate the various patterns of presentations on digital breast tomosynthesis (DBT) of pathologically-proven radial scar (RS) without associated atypia; 2) to emphasize that benign RS can mimic invasive carcinoma on DBT images; 3) to show mammographic, sonographic and Magnetic Resonance Imaging (MRI) correlation for each pattern of DBT presentation, focusing on differences between DBT and DM. Background Radial scar (RS) of the breast has been previously described in the literature under several different names such as radial sclerosing lesion, scleroelastotic lesion, indurative mastopathy, nonencapsuled sclerosing lesion, sclerosing papillary proliferation, and, if larger than 1.0 cm, complex sclerosing lesion. RS is a benign breast lesion characterized by a central fibroelastotic core with ducts and lobules radiating outward, living the lesion its characteristic stellate appearance (Fig. 1). Pathologic examination of a RS reveals the presence of a diverse array of pathologic entities located at the periphery of the lesion, including typical epithelial hyperplasia, adenosis, papillomatosis, atipica epithelial hyperplasia, ductal carcinoma in situ (DCIS), and early stage invasive carcinomas. The clinical significante of RS is threefold: first, at histopathologic examination, RS can be mistaken for a carcinoma (in particolar tubular histotype); second, discrete foci of carcinoma may be found within or adiacent to some RS; third, RS may be an independent risk factor for breast cancer. In particular, because of the peripheral location of malignant foci within some RS, percutaneous biopsy of RS is considered not to be reliable in ruling out malignancy, due to potential sampling error. Studies addressing the issue of invasive and/or intraductal carcinoma occurring at surgery after a percutaneous diagnosis of RS have reported very variable underestimation rates, ranging from 0% to 40%. Page 2 of 20

3 As a consequence, excisional rather than percutaneous biopsy has been generally recommended when imaging findings are consistent with RS, but controversy exists regarding the need for surgical excision after a percutaneous diagnosis of RS. Although most RS are found incidentally at microscopic evaluation of biopsy specimens of another lesion, the widespread use of mammography and tomosynthesis has led to an increase in radiologic identification of this lesion. Although the mammographic features of RS have been previously described, less is known about its presentation on tomosynthesis. Use of Digital Breast Tomosynthesis (DBT) is increasing in clinical practice thanks to its ability to reduce breast tissue overlapping. The ability to provide ''slices'' through the breast and reduce the noise contributed by the normal breast structures is the major benefit from tomosynthesis. DBT technology is essentially a modification of a digital mammography (DM) unit to enable the acquisition of a three dimesional (3 D) volume of thin-section data. Images are reconstructed in conventional orientations by using reconstruction algorithms similar to those used in computed tomography (CT). Sonography was initially considered to have no role in the imaging RS. However, it has been demonstrated that RS are visible on sonograms, and when they are seen, they are more conspicuous on sonography than on mammography. In addition, sonography can be helpful in women in whom mammographic findings are subtle or apparent on only one mammographic view to aid the localization of the lesion before percutaneous biopsy. On ultrasound, a radial scar, which disturbs the architecture of surrounding breast parenchyma, is often ill-defined round, oval or lobulated lesion with variable internal echoes. The role of sonography in differentiation between RS and breast cancer is still uncertain. RS are known to show very variable patterns of presentation also on MRI, including masses, non-mass lesions, architectural distortion and foci, with up to one third of RS being MR-occult, according to one study, and very variable kinetics characteristics. A few studies have tried to determine whether any of the MRI features of RS could be useful in differentiating benign and malignant lesions or not, with uncertain results. Images for this section: Page 3 of 20

4 Fig. 1: Photograph of a surgical specimen shows a typical radial scar (Hematoxylin-eosin stain [H&E]; original magnification, x1). A central nidus of dense fibroelastotic tissue with radiating fibrous bands (grey circle) is surrounded by a "corona" of glandular proliferation and cysts (white "corolla"). Linda A. et al. Spectrum of MRI presentations of radial scars of the breast: A pictorial review. Epos ECR 2010; C-0332 Page 4 of 20

5 Findings and procedure details According to our experience RS are better visualized and evaluated on DBT than DM (Fig. 2). DBT is also able to identify RS that are occult on DM, in particular in case of dense breast tissue (Fig 3,4). According to our experience RS show three DBT patterns (Fig. 5): Pattern 1: * Architectural distortion (Fig. 6-9), with or without associated microcalcifications. The most typical appearance of RS presenting as architectural distortion ("black star") on mammography has been described by Tabar and Dean, including: central radiolucency; radiating long, thin spicules; varying appearance in different projections; radiolucent linear structures parallel to the spicules and the absence of palpable lesion or skin changes. All these features are very well demonstrated by DBT because of the reduction of superimposed glandular tissue. The relative low density of the centre plays an important role in the differential diagnosis between RS and carcinoma, in which the centre tends to be more dense and the translucent area is characteristically absent. The presence of a radiolucent core is very well demonstrated by DBT. When sonographically visible, RS presenting as architectural distortions, are shown as focal areas of acoustic shadowing without a discernable mass. The same lesions are shown on MRI as stellate "architectural distortions", without mass effect; they usually show mild or no enhancement and are better appreciated on non-contrast-enhanced images. Pattern 2: * Stellate opacity (Fig 10,11), that is a tridimensional mass, having ill defined borders, featuring spiked linear extensions, or spicules, which lead out towards adjacent tissue and is indistinguishable from a breast cancer. These lesions are shown on sonography as irregularly-shaped, hypoechoic masses with ill-defined borders and posterior acoustic shadowing, virtually identical to carcinoma of the breast. MRI also reveals as an irregular or spiculated "tumor like" mass with morphology and enhancement kinetics that mimic those of invasive breast cancer. Pattern 3: Page 5 of 20

6 * Microcalcifications (Fig. 12,13), with round, punctuate and ill-defined morphology. They usually are not visible on sonography and MRI. Images for this section: Fig. 2: 50 year-old woman, follow-up after left mastectomy. Mammogram shows heterogeneously dense fibroglandular tissue (BIRADS C), with architectural distortion and associated amorphous microcalcifications at the supero-lateral quadrant of the right breast (a,b). The two-view (CC and MLO) DBT examination confirmed the lesion and better defines its spiculated margins (c,d). Page 6 of 20

7 Fig. 3: 50 year-old woman, callback after a screening mammogram (first examination). Screening mammogram shows heterogeneously dense fibroglandular tissue (BIRADS C), with faint architectural distortion at the outer quadrants of the right breast. A twoviews right DBT examination is performed: the architectural distortion detected on mammography is not confirmed (superimposed breast tissue); however a second area of architectural distortion is highlighted between the right superior quadrants (c,d). US examination was negative in both areas. A DBT-guided vacuum-assisted biopsy was performed, resulting in a radial scar. Page 7 of 20

8 Fig. 4: Same case as figure 3. MRI reveals an area of architectural distortion, hypointense in the T1w unenhanced sequences, with slight and progressive contrast enhancement. Radial scar was confirmed at surgical excision. Page 8 of 20

9 Fig. 5: Patterns of DBT presentation of radial scar. Linda A. et al. Spectrum of MRI presentations of radial scars of the breast: A pictorial review. Epos ECR 2010; C-0332 Page 9 of 20

10 Fig. 6: Example of DBT pattern 1: "Architectural Distortion". 64 year-old woman, spontaneous screening. Mammogram reveals a heterogeneously dense breast tissue (BIRADS C). As compared to previous examination, an area of architectural distortion is more evident in the upper quadrants of the right breast (a,b). A two-view DBT examination confirms the distortion, shows its radiolucent core and the presence of diffuse, amorphous microcalcifications (c,d). Sonographic examination was negative. A DBT-guided vacuumassisted biopsy was performed, resulting in a complex sclerosing lesion, that was confirmed at surgical excision. Page 10 of 20

11 Fig. 7: Same case as figure 6. MRI examination reveals an architectural distortion, better demonstrated in pre-contrast T1-w image (d), showing mild and heterogeneous nonmass like enhancement (e). "Signal void" artefact due to the presence of metallic clip placed after percutaneous biopsy is also demonstrated. Page 11 of 20

12 Fig. 8: Example of DBT pattern 1: "Architectural Distortion". 50 year-old woman undergoing her first screening mammography. Mammogram reveals heterogeneously dense tissue (BIRADS C) with an area of architectural distortion at the supero-lateral quadrant of the right breast (a,b). A two-views (CC and MLO) DBT examination was performed: the lesion was confirmed and its radiolucent core was better demonstrated (c,d). Page 12 of 20

13 Fig. 9: Same case as figure 8. The sonographic (US) examination reveals an area of acoustic shadowing without a discrete mass with peripheral vascularization (e,f). A USguided core-needle biopsy was performed, showing a complex-sclerosing lesion, later confirmed at surgical excision. MRI examination demonstrates an heterogeneous mass lesion, with irregular margins and a rapid enhancement followed by wash-out (g,h). Page 13 of 20

14 Fig. 10: Example of DBT pattern 2: "Stellate Opacity". 75 year-old woman, spontaneous screening. The mammography reveals heterogeneous fibroglandular tissue (BIRADS C); an irregular mass with ill-defined margins and associated linear microcalcifications are shown at the upper outer quadrant of the left breast (a,b). The two-views DBT examination better defines the spiculated margins of the lesion (c,d). Page 14 of 20

15 Fig. 11: Same case as figure 10. The ultrasonographic appearance is that of a hypoechoic, irregular mass with not circumscribed margins, without significant vascularization (e,f). An US-guided biopsy was performed, revealing a radial scar, that was later confirmed at surgical excision. MRI examination reveals an irregularly-shaped mass-like enhancement, with spiculated margins (g,h); small "signal void" artifact is present due to to the clip-mark left after biopsy. Page 15 of 20

16 Fig. 12: Example of DBT pattern 3: "Microcalcifications". 64 year-old woman, undergoing screening mammogram which revealed a group of fine pleomorphic microcalcifications in the right retroareolar region (a,b). The right two-views DBT examination confirms the microcalcifications and reveals the presence of a faint architectural distortion with a radiolucent core (c,d); no US correspondance is found. A DBT-guided biopsy was then performed resulting in a radial scar, that was confirmed at surgery. Page 16 of 20

17 Fig. 13: Same case as figure 12. MRI does not demonstrate any contrast enhancement in the area of the lesion ("signal void" artefact is present due to the metallic clip). Page 17 of 20

18 Conclusion RS detection increased dramatically over the past few years. In our experience DBT is better than DM in the detection of RS. This might depend on the planar configuration of RS, which may have varying appearances on orthogonal views. Benign RS can have several appearances on DBT. The spectrum of DBT presentations spans from occult lesions to spiculate opacities, indistinguishable from invasive carcinoma. Appreciation of these diverse appearances might help avoid misdiagnosis when evaluating DBT examinations. However, the differential diagnosis between RS and malignancy can only be solved by the histological examination after surgical excision of the entire lesion. Personal information Elisa Zanelli, MD Institute of Radiology, Departments of Medical and Biological Sciences University of Udine UDINE ITALY References 1. Baker JA, Lo JY. Breast tomosynthesis: state-of-the-art and review of the literature. Acad Radiol. 2011;18(10): Becker L, Trop I, David J, et al. Management of radial scars found at percutaneous breast biopsy. Can Assoc Radiol J 2006;57:72-78 Page 18 of 20

19 3. Brenner RJ, Jackman RJ, Parker SH, et al. Percutaneous core needle biopsy of radial scars of the breast: when is excision necessary? Am J Roentgenol 2002; 179: Cawson JN. Can sonography be used to help differentiate between radial scars and breast cancers? Breast 2005; 14: Cherel P, Becette V, Hagay C. Stellate images: anatomic and radiologic correlations. Eur J Radiol 2005;54: Cohen MA, Sferlazza SJ. Role of sonography in evaluation of radial scars of the breast. Am J Roentgenol 2000; 174: Farshid G, Rush G. Assessment of 142 stellate lesions with imaging features suggestive of radial scar discovered during population-based screening for breast cancer. Am J Surg Pathol 2004; 28: Fasih T, Jain M, Shrimankar J, et al. All radial scars/complex sclerosing lesions seen on breast screening mammograms should be excised. Eur J Surg Oncol 2005; 31: Kennedy M, Masterson AV, Kerin M, et al. Pathology and clinical relevance of radial scars: a review. J Clin Pathol 2003; 56: Lee JM, Liberman L, Morris EA, et al. MR imaging findings of radial scars. Am J Roentgenol 2003;180: Linda A, Zuiani C, Furlan A, et al. Radial Scars without atypia Diagnosed at ImageGuided Needle Biopsy: How Often is Associated Malignancy Found at Subsequent Surgical Excision, and do Mammography and Sonography Predict Which Lesions are Malignant? Am J Roentgenol 2010; 194(4): Linda A, Zuiani C, Furlan A, et al. Nonsurgical management of high-risk lesions diagnosed at core needle biopsy: can malignancy be ruled out safely with breast MRI? Am J Roentgenol 2012; 198(2): Linda A, Zuiani C, Londero V et al. Magnetic resonance imaging of radial sclerosing lesions (radial scars) of the breast. Eur J Radiol 2012; 81(11): Page 19 of 20

20 14. Myong JH et al. Imaging features of complex sclerosing lesions of the breasts. Ultrasonography 2014; 33: Park J.M, Franken E.A, Garg M, et al. Breast tomosynthesis: Present considerations and Future Application. Radiographics 2007; 27: S231-S Patterson JA, Scott M, Anderson N, et al. Radial scar, complex sclerosing lesion and risk of breast cancer. Analysis of 175 cases in Northern Ireland. Eur J Surg Oncol 2004; 30: Pediconi F, Occhiato R, Venditti F, et al. Radial scars of the breast: contrastenhanced magnetic resonance mammography appearance. Breast J 2005;11: Perfetto F, Fiorentino F, Urbano F, et al. Adjunctive diagnostic value of MRI in the breast radial scar. Radiol Med 2009;114: Shetty MK. Radial scars of the breast: sonographic findings. Ultrasound Q 2002;18: Tabar LPD. Teaching Atlas of Mammography. 3rd edn. Stuttgart: Thieme; 2000 Page 20 of 20