Benign breast lesions frequently encountered on MR

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1 Benign breast lesions frequently encountered on MR Poster No.: C-1385 Congress: ECR 2012 Type: Educational Exhibit Authors: J. R. Almeida 1, J. C. Marques 2 ; 1 Lisbon/PT, 2 lisbon/pt Keywords: Hemangioma, Cysts, Abscess, Education, MR, Breast DOI: /ecr2012/C-1385 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 17

2 Learning objectives Review the most common benign lesions of the breast and characterize their appearance on MRI Background The vast majority of the lesions that occur in the breast are benign. Much concern is given to malignant lesions of the breast because breast cancer is the most common malignancy in women in Western countries; however, benign lesions of the breast are far more frequent than malignant ones. With the use of mammography, ultrasound and magnetic resonance imaging of the breast, the diagnosis of benign breast disease can be accomplished without surgery in a majority of patients. The term "benign breast lesions encompasses a heterogeneous group of lesions that may present a wide range of symptoms or may be detected as incidental microscopic findings. Usually the use of magnetic resonance imaging is reserved for the clinical situations in which the probability of finding breast carcinoma is high, (MRI indications- Table 1), but there is still a greater probability of finding a benign breast lesion on breast MR than a carcinoma. ACR indications for Breast MRI Lesion characterization Response to neo-adjuvant chemotherapy Extent of infiltrating lobular carcinoma Extent of infiltrating ductal carcinoma Axillary node metastases- unknown primary Invasion deep to fascia Contralateral breast screening 5% synchronous occult cancers Residual disease post lumpectomy Page 2 of 17

3 Recurrence of breast cancer Surveillance of high risk patients Table 1 - ACR indications for Breast MRI. Imaging Findings Certain MR imaging findings are predictive of benign disease: Smooth or lobulated borders Homogeneous Absence of lesion enhancement Enhancement less than surrounding breast stroma The presence of nonenhancing internal septations Parallels Cooper's Ligaments In this review, the most frequently seen benign breast lesions of the breast are summarized as Mass lesions and Non-Mass lesions (table 2). Mass lesions Fibroadenoma Cyst Fat Necrosis Lymph node Hamartoma Abscess Seroma Hematoma Hemangioma Non Mass lesions Fibrocystic Disease Sclerosing Adenosis Radial Scar Parenchymal Scar Table 2 - Classification of benign lesions on MRI Imaging findings OR Procedure details 1. Fibroadenoma Most common benign neoplasm of the breast Page 3 of 17

4 2. Cysts They occur in all age groups - peak incidence 30y. Histologically - epithelial and stromal elements surrounded by a pseudocapsule. MR imaging features of fibroadenomas vary with their histologic subtype: Juvenile or myxoid On T2 WI exhibit a high signal intensity compared with the adjacent fibroglandular tissue Internal enhancement is homogeneous, or dark internal septations are visible. (high negative predictive value for breast cancer. Exhibit fast enhancement with a persistent time course Figure 1 Sclerotic (Fibrotic) Exhibit only weak enhancement or no enhancement at all Internal architecture is usually not evaluable because of the absence of enhancement. T2 WI - extremely hypointense signal darker than that of the pectoral muscle. The most common breast lesion seen on MRI True cystic disease occurs most often between the ages of 45 to 55 Histologically, a cyst is a focal dilatation of a duct - fluid collection surrounded by a thin layer of apocrin epithelium. T2 WI - High fluid signal, round, sharply circumscribed masses. T1 WI fat suppressed - signal intensity less than or equal to the surrounding breast tissue. With increasing proteinaceous content of the cysts, signal on TSE T2- weighted images decreases and that on precontrast T1-weighted images increases Do not enhance. Inflamed cysts - may have a peripheral rim of enhancement Figures Fat Necrosis Postoperative fat necrosis (oil cysts) Histologically, recent fat necrosis consists of a collection of inflammatory cells, lipid-laden macrophages and hemorrhage. As time goes by the necrotic tissue become surrounded by a giant cell granulomatous reaction and later fibrosis T1 WI non contrast show very low signal intensity mass of variable shape, surrounded by a rim of variable signal intensity Contrast enhanced T1 WI: the appearance is variable (depends on the various stages of development). When central fatty tissue is visible it facilitates the diagnosis Page 4 of 17

5 Sometimes is difficult to distinguish from recurrent breast cancer - history of trauma and mammographic features are helpful. Figure 5 4. Lymph node Normal anatomy of the breast Most commonly in the axilla and axillary tail, but may be seen in other quadrants (intra-mammary lymph node), less commonly in the lower inner quadrant Oval and circumscribed, <1,5 cm, classic reniform shape Contrast enhanced T1 WI with fat suppression: enhancing mass, with a nonenhancing central hilum. Kinetic analysis: rapid enhancement and washout (similar to malignancy, therefor misleading)) T1 WI - central fatty focus Inflammatory/ Hyperplastic lymph nodes cannot be distinguished from metastatic lymph nodes Figure 6 5. Hamartoma Rare, solitary benign malformations that resemble neoplasms, but result from faulty development of breast tissues. Circumscribed lesions containing varying amounts and combinations of normal breast tissue, mature fat, adipose tissue, muscle and connective tissue, surrounded by a thin fatty capsule. Diagnostic mammographic appearance Contrast enhanced T1 WI fat saturated: there may be slight enhancement if glandular elements are present T2 WI - a fatty capsule may be visible. Figure 7 6. Abscess Result from unresolved local infection, caused by obstruction of the duct near the nipple and acute/chronic or lactational mastitis. Palpable, associated with erythema, edema and induration of overlying skin and pain. T2 WI - focal moderate to high signal mass, shape and margins vary from round to irregular, thickened skin. T1 WI - Mass with central medium signal with a lower signal capsule surrounding the mass. Contrast enhanced T1 fat sat - non-enhancing central region surrounded by an early intensely enhancing rim. Kinetics similar to malignancy History and clinical examination are very helpful. Page 5 of 17

6 Figure 8 7. Seroma Tumor like collections of fluid in breast tissue that occur following excisional biopsy, lumpectomy, mastectomy and plastic surgery procedures (breast augmentation, breast reduction, etc.) Common complication in the immediate postoperative period. T2 WI - circumscribed collection with high signal intensity T1 WI with fat suppression - low signal intensity Contrast enhanced T1 WI with fat supression- does not enhance, sometimes rim enhancing Figure 9 8. Hematoma Collection of blood caused by trauma to the breast (injury, biopsy, surgery) T2/T1 WI - circumscribed mass usually hiperintense (variable according to age of blood products) Contrast enhanced T1WI with fat suppression - does not enhance Figure Hemangioma Benign Vascular tumors Histologically there are two types: the capillary hemangiomas and the cavernous heamngioma Hemangiomas of the breast can be divided into intra-lobular and extralobular types. Incidence of 1,2% to 11% T2 WI / T1 WI fat suppression - circumscribed mass hyperintense Contrast enhanced T1WI with fat suppression - usually slow enhancement Figure Fibrocystic Disease Most common bilateral disorder of the breast Results from distrortion and exaggeration of normal menstrual cyclic changes of ductal epithelium and stroma Not associated with an increased risk to breast cancer Consists of cysts of varying sizes, stromal fibrosis, and apocrine metaplasia T1/T2 WI non contrast - difficult to distinguish from normal parenchyma (variable appearance dependent on the water and collagen content of the tissues) Page 6 of 17

7 Contrast enhanced T1 WI - presence of stippled enhancement, occasionally this pattern may seem to coalesce and appear as a region of clumped enhancement or even heterogeneous large mass Generally patterns vary with menstrual cycle - less conspicuous in the midcycle. Figure Sclerosing Adenosis One of the benign causes of enhancement on MR Histologically consists of swirls of desmoplastic proliferation with variable amounts of epithelium and myoepithelium. The MR enhancement depends on the histologic pattern - may be patchy or diffuse. Figure Radial Scar Pathologically has a stellate configuration consisting of a central fibroelastic sclerotic core. Radiating from this core are proliferative elements consisiting of epithelial hyperplasia, pappilomatosis and sclerosing adenosis. Associated with malignancy -tubular carcinoma Contrast enhanced T1 WI with fat suppression - enhancing irregular or speculated mass that is indistinguishable from carcinoma Enhancement is usually heterogeneous and kinetic patterns are unreliable and can overlap Biopsy is required Figure Parenchymal Scar Scar versus recurrence of carcinoma in the conserved or reconstructed breast The MRI appearance of a normal scar evolves over time Immediately after surgery on contrast enhanced T1 WI with fat suppression there may be moderate enhancing surrounding the operative bed. Usually after 6 months the normal parenchymal scar has matured into dense fibrosis that doesn't enhance. Figure 15 Images for this section: Page 7 of 17

8 Fig. 1: T2 WI and Diffusion WI show a Myxoid Fibroadenoma Fig. 2: T2 WI and T1 WI with fat supression show a simple cyst (arrow) Page 8 of 17

9 Fig. 3: T2WI and T1WI with fat supression show a hemorrhagic cyst - hypointense on T2WI and Hyperintense on T1 WI (arrow) Fig. 4: T2 WI shows multiple billateral simple cysts Page 9 of 17

10 Fig. 5: T2WI and Contrast enhanced T1WI with fat supression show postoperative fat necrosis Fig. 6: T2WI and Contrast enhanced T1WI with fat supression show a small intramammary lymph node (arrow) Page 10 of 17

11 Fig. 7: T2WI and Contrast enhanced T1WI with fat supression show a hamartoma(arrow) Fig. 8: T2WI and Contrast enhanced T1WI with fat supression show a retroareolar abscess(arrow) Page 11 of 17

12 Fig. 9: T2WI and Contrast enhanced T1WI with fat supression show a seroma(arrow) Fig. 10: T2WI and Contrast enhanced T1WI with fat supression show a hematoma(arrow) Page 12 of 17

13 Fig. 11: T2WI and Contrast enhanced T1WI with fat supression show a large cavernous hemangioma(arrow) Fig. 15: T2WI and Contrast enhanced T1WI with fat supression show a post-operative scar with no evidence of recurrence Page 13 of 17

14 Fig. 13: T2WI and Contrast enhanced T1WI with fat supression shows Sclerosing Adenosis - confirmed by pathology(arrow) Page 14 of 17

15 Fig. 12: T2WI and Contrast enhanced T1WI with fat supression in a patient with fibrocystic disease. Page 15 of 17

16 Fig. 14: T2WI and contrast enhanced T1WI with fat supression show a radial scar Page 16 of 17

17 Conclusion Benign lesions of the breast are far more frequent than malignant ones, with the use of mammography, ultrasound and magnetic resonance imaging, the diagnosis of benign breast disease can be accomplished without surgery. It is important for radiologists to recognize many variable appearances of benign entities on MR, both to distinguish them from in situ and invasive breast cancer and to assess a cancer patient's risk of developing breast, so that the most appropriate treatment modality for each case can be established. Personal Information Dr. Joana Almeida Radiology Department Hospital Curry Cabral Lisboa/Portugal mjalmeida81@gmail.com References 1. Liberman, Laura; Morris, Elizabeth et al; Breast MRI: Diagnosis and Intervention, Springer; 1 edition (2005) 2. Guray, Merrih, Sahin, Aysegul; Benign Breast Diseases: Classification, Diagnosis and Management; The Oncologist May 2006 vol. 11 nº Kuhl, Christiane K., Concepts for Differential Diagnosis in Breast MR Imaging; Magn Reson Imaging Clin N Am 14 (2006) Schnall, Mitchell D. MD; Breast MR imaging; Radiologic Clinics of North America Am 41 (2003) Saslow et al. American Cancer Society Guidelines for Breast Screening with MRI as an Adjunct to Mammography. Cancer Journal for Clinicians 57 (2007) Kuhl, Christiane K. Current Status of Breast MR Imaging. Radiology (2007) 244: Fischer, U and Brinck, U. Practical MR mammography. Thieme, Tartar, M., Comstock, C. and Kipper, M. Breast Cancer Imaging: A multidisciplinary, multimodality approach. Elsevier Health Sciences, Page 17 of 17