Cystic lesions of the breast.

Cystic lesions of the breast. Poster No.: C-0411 Congress: ECR 2015 Type: Educational Exhibit Authors: K. Kubota; Bunkyo-City Tokyo/JP Keywords: Cysts, Cancer, Diagnostic procedure, Ultrasound, MR, Mammography, Breast DOI: 10.1594/ecr2015/C-0411 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. www.myesr.org Page 1 of 37

Learning objectives The purpose of this educational exhibit is to: 1. To understand the basis of cystic lesions of the breast on mammography, ultrasound, and MRI. 2. To determine appropriate management recommendations for cystic lesions based on BI-RADS 2013 assessment. Background Cystic breast lesions include a wide spectrum of breast diseases ranging from benign to malignant. For the appropriate diagnosis, it is very important to understand the characteristics of each modality and the pathological characteristics of each lesion. Mammography Mammography displays the differences of tissue X-ray attenuation in gray scale. Since the X-ray attenuation coefficient of either normal breast tissues, tumors, or cystic lesions are very similar, it is difficult to distinguish them with the density of the lesion on mammography only (Fig. 1). Page 2 of 37

Fig. 1: Only a part of the mass is identified on this mammography, but it is difficult to determine whether a cyst or a solid mass. Ultrasound: A simple cyst was found on ultrasound. References: Radiology, Medical Hospital of Tokyo Medical and Dental University Bunkyo-City Tokyo/JP X-ray attenuation coefficient at 20KeV is shown below. Fat 0.40(cm ) -1 Mammary gland 0.80(cm ) Tumor 0.85(cm ) Water 0.90(cm ) Calcification 12.5(cm- ) -1-1 -1 1 Composition of the breast affects the detection of the lesion. Thus, the lesion is often obscured in the dense breast. Page 3 of 37

It is difficult to judge cystic or solid on mammography, even if a lesion was found. Ultrasound Ultrasound is thought to be the most useful modality for cystic lesions by taking advantage of ultrasonic characteristic and its high spatial resolution. Color doppler / power doppler images and elastography is also useful for the diagnosis of cystic lesions, and they are included in BI-RADS lexicons. By ACR BI-RADS lexicons, complex cystic and solid mass is a suspicious lesion and it requires biopsy. Other benign cystic lesion (such as simple cyst, clustered microcyst, complicated cyst) must be distinguished. Ultrasonic characteristics of cysts Scattering does not occur in the cyst, and showing anechoic feature. Attenuation does not occur in the cyst, and posterior enhancement is seen due to the effect of mechanical amplification by STC (sensitivity time control). Page 4 of 37

Fig. 2: Scattering or attenuation does not occur in cysts. References: Radiology, Medical Hospital of Tokyo Medical and Dental University - Bunkyo-City Tokyo/JP Recently, compound Imaging has come to be used. It eliminates artifacts by averaging several overlapping angles of US images, but the posterior enhancement may be less apparent. Pitfall: Lesion with high cellularity tumor (i.e. malignant lymphoma) shows very low echoic feature, and it often mimics cyst. New technologies of Ultrasound Contrast-enhanced ultrasound (Fig 3) Intravenous injection of Sonazoid (perflubutane, Daiichi-Sankyo Pharmaceuticals) consists of perflubutane gas microspheres stabilized by hydrogenated egg-phosphatidylserine membrane. The collapse of the intravascular microbubbles is depicted on the US image. SMI (Superb Micro-Vascular Imaging) (Fig 4) Low blood flow can be shown without motion artifacts. MRI Page 5 of 37

MRI has high contrast resolution and good spatial resolution. The sensitivity of breast MRI for the detection of breast cancer is approximately 95% and it is higher than other modalities. By MRI, contrast enhancement is helpful in detection of solid part and some other signal assessment is useful. Pitfalls: Many of the cysts shows high signal on T2 weighted images and low signal on T1 weighted images. On the other hand, some cysts exhibit high signal on T1-weighted images by concentrated component or bleeding component. Inflammatory cysts or complicated cysts sometimes show rim enhancement and mimic invasive cancer. These cysts contain fluid and there is no enhancement inside the cysts. High signal on Diffusion weighted image is sometimes seen due to T2 shinethrough artifact. Images for this section: Fig. 2: Scattering or attenuation does not occur in cysts. Page 6 of 37

Fig. 1: Only a part of the mass is identified on this mammography, but it is difficult to determine whether a cyst or a solid mass. Ultrasound: A simple cyst was found on ultrasound. Page 7 of 37

Fig. 3: Contrast-enhanced ultrasound of intracystic papillary carcinoma. The ultrasound contrast agent Sonazoid (perflubutane) was injected intravenously. The blood flow of a tiny solid part in the cyst was identified. Page 8 of 37

Fig. 4: SMI (Superb Micro-Vascular Imaging) Low blood flow of the intracystic tumor could be detected. Page 9 of 37

Findings and procedure details In BI-RADS US 2013 (BI-RADS atlas 5th), these types of cystic lesions are classified. Simple cyst Complicated cyst Clustered microcyst Complex cystic and solid mass 1. Simple cyst A mass that shows no echo or almost no echo inside it can be diagnosed as a cyst. Fig. 5: Simple cyst. This cyst shows no inside echo and shows posterior enhancement. References: Radiology, Medical Hospital of Tokyo Medical and Dental University Bunkyo-City Tokyo/JP Page 10 of 37

On the elastography strain image, an aliasing artifact that appears as a blue-green-red (BGR) pattern can be seen in a simple cyst. Although blood flow cannot be found in the cyst in color or power doppler images, it must be noted that tiny blood flow in solid masses may not be detected neither. Fig. 6: Cysts. Strain elastography shows blue-green-red (BGR) pattern that suggests cysts. On a color doppler image, no blood flow is detected. References: Radiology, Medical Hospital of Tokyo Medical and Dental University Bunkyo-City Tokyo/JP BI-RADS assessement for simple cyst is Category 2. 2. Complicated cyst and other cyst Cyst with fluid level Page 11 of 37

Fig. 7: When high echoic collection is seen in the upper layer, it is oil cyst. Collection of hemorrhage precipitates in the lower side. References: Radiology, Medical Hospital of Tokyo Medical and Dental University Bunkyo-City Tokyo/JP Oil cyst: Oil is lighter than water. When a high echoic collection is seen in the upper layer, it is oil cyst. Collection of hemorrhage precipitates in the lower side. Concentrated cyst: Cyst containing high viscous thing, milk state or oil-like retention thing. Page 12 of 37

Fig. 8: Concentrated cyst with posterior shadowing. References: Radiology, Medical Hospital of Tokyo Medical and Dental University Bunkyo-City Tokyo/JP Internal echo is shown in the concentrated cyst. Posterior shadowing, enhancing, or no change. Well-defined tumor with posterior shadowing can be diagnosed as concentrated cyst since no breast cancer shows both well-defeined margin and posterior shadowing. Rim enhancement of cyst Page 13 of 37

Fig. 9: Inflammatory cysts or complicated cysts sometimes show rim enhancement. References: Radiology, Medical Hospital of Tokyo Medical and Dental University Bunkyo-City Tokyo/JP Inflammatory cysts or complicated cysts sometimes show rim enhancement and mimic invasive cancer. These cysts contain fluid and there is no enhancement inside the cysts. BI-RADS assessement is Category 3 for these two cases Isolated, complicated cyst with uniform low-level echoes. Microlobulated or oval masses composed entirely of clustered microcysts. 3. Complex cystic and solid mass There are two types of complex cystic and solid mass Page 14 of 37

Fig. 10: Two types of complex cystic and solid mass. Intracystic tumor Cystic lesion in a tumor References: Radiology, Medical Hospital of Tokyo Medical and Dental University Bunkyo-City Tokyo/JP Intracystic tumor Solid part in a cystic mass. Though steep and pedicellation morphology suggests more benignity, whereas wide base and progression outside the cyst wall suggests more malignancy, it may be difficult to distinguish papilloma from cancer in many cases. Cystic lesion in a tumor A solid mass with cystic lesion in the mass. The diagnosis applies to the diagnosis of the solid mass. BI-RADS assessement for both tumors are simple, Category 4 (2-95% malignancy). Page 15 of 37

The recommended management is biopsy, and VAB (Vacuum assited biopsy) is generally recommended. 4. Representative cases Intracystic tumor Intracystic/intraductal papilloma (Fig.11-13) Small solitary intraductal papilloma: Tiny lesion, enhancing focus on MRI. Large solitary intraductal papilloma: Mass lesion, sometimes showing rim enhancement. Peripheral intraductal papilloma: Non-mass enhancement(linear / regional enhancement) on MRI. Distinction with cancer is often difficult. Intracystic/intraductal papillary carcinoma (Fig. 14) Rare intracystic lesions Ductal adenoma (Fig. 15) Adenomyoepithelioma (Fig. 16) Lactating adenoma (Fig. 17) Cystic lesion or confusing part in a tumor DCIS (ductal carcinoma in situ) (Fig. 18) Fibroadenoma (Fig. 19) Phyllodes tumor (Fig. 20) Mucinous cancer (Fig. 21) Triple negative breast cancer (Fig. 22) Metaplastic carcinoma (spindle cell carcinoma) (Fig. 23) Malignant Lymphoma (Fig. 24) Images for this section: Page 16 of 37

Fig. 5: Simple cyst. This cyst shows no inside echo and shows posterior enhancement. Page 17 of 37

Fig. 6: Cysts. Strain elastography shows blue-green-red (BGR) pattern that suggests cysts. On a color doppler image, no blood flow is detected. Page 18 of 37

Fig. 7: When high echoic collection is seen in the upper layer, it is oil cyst. Collection of hemorrhage precipitates in the lower side. Page 19 of 37

Fig. 8: Concentrated cyst with posterior shadowing. Page 20 of 37

Fig. 9: Inflammatory cysts or complicated cysts sometimes show rim enhancement. Page 21 of 37

Fig. 10: Two types of complex cystic and solid mass. Intracystic tumor Cystic lesion in a tumor Page 22 of 37

Fig. 11: Intraductal papilloma US: Intracystic tumor. MRI: Mass with rim enhancement, suggestive of invasive cancer. BI-RADS assessment: Category 4 Biopsy: Intraductal papilloma. Page 23 of 37

Fig. 12: Tiny intraductal papilloma. There was bloody nipple discharge. Tiny intraductal papilloma was depicted as a focus on MRI. BI-RADS assessment: Category 3 Biopsy: Intraductal papilloma. Page 24 of 37

Fig. 13: Intraductal papilloma. US: Complex cystic and solid mass. MRI: Mass with irregular shape and margin. BI-RADS assessment: Category 4 Biopsy: Intraductal papilloma. Page 25 of 37

Fig. 14: Intracystic papillary carcinoma with invasion. Ultrasound: Complex cystic and solid mass. High blood flow was detected on solid part. BI-RADS 4. MRI: invasive lesion was detected. BI-RADS 5. Page 26 of 37

Fig. 15: Ductal adenoma US: Cystic lesion (complex cystic and solid mass, intracystic tumor), BI-RADS 4. MRI: irregular mass, BI-RADS 4. Ductal adenoma is a rare benign cystic lesion, but a lesion which can mimic carcinoma. Page 27 of 37

Fig. 16: Adenomyoepithelioma US: Irregular cystic and solid mass, BI-RADS 4. MRI: irregular mass, BI-RADS 4. Adenomyoepithelioma is a rare benign cystic lesion, but a lesion which can mimic carcinoma. Page 28 of 37

Fig. 17: Lactating adenoma of a pregnant woman in 30s Intracystic lesion was detected on Ultrasound. Elastography showed BGR sign. There was very high blood flow in the low echoic part. Thus, the low echoic part was the solid part whereas the high echoic part was the concentrated fluid collection in this case. BI-RADS assessment category 4. It was diagnosed by core needle biopsy. Page 29 of 37

Fig. 18: DCIS Mammography was negative. US showed complex cystic and solid mass at 5 o'clock. MRI depicted segmental clustered ring enhancement, which is characteristic in DCIS. BI-RADS assessment: Category 5 Page 30 of 37

Fig. 19: Fibroadenoma Oval shape, smooth margin, and almost heterogeneous echo. Sometimes there may be low echoic lesion which can not be distinguished with cystic part at a glance. It may also be accompanied by a small cystic component. BI-RADS assessment: Category 4. (Usual fibroadenomas can be Category 3, but this case was slightly heterogeneous and significantly hypervacular.) Page 31 of 37

Fig. 20: Phyllodes tumor A case of large tumor with cystic part. Phyllodes tumor was classically called cystsarcoma phyllodes and may contain an epithelial cystic lesion. Page 32 of 37

Fig. 21: Mucinous carcinoma A: Ultrasound. B: MRI, T2-weighted image. C: MRI, contrast-enhanced image. Mucinous carcinoma has cancer cells in mucous lakes, thus very high signal intensity is seen on T2-weighted images and cystic part is sometimes detected. Contrast enhancement pattern is persistent, and the differential diagnoses are intracystic tumors, fibroadenomas, and phyllodes tumors on MRI. Page 33 of 37

Fig. 22: Triple negative breast cancer (TNBC). TNBCs have some distinctive features such as oval or round shapes and cystic part (high signal on T2 weighted images, non-enhancing part on contrast enhanced images) through tumoral necrosis. BI-RADS assessment: Category 5 Page 34 of 37

Fig. 23: Metaplastic carcinoma (spindle cell carcinoma) The necrosis and the cystic part might be accompanied in metaplastic carcinoma and the squamous cell carcinoma. BIRADS assessment: Category 5 Page 35 of 37

Fig. 24: Malignant lymphoma. Malignant lymphoma is not a cystic lesion, but it mimics cysts due to the very low echoic lesion caused by very high cellularity. Page 36 of 37

Conclusion This presentation showed the basics of each modality, the classification of the lesion, and the representative cases about a cystic lesion. It is very important to understand Complex cystic and solid mass. By understanding the image features of many types of cystic lesions, a suitable assessment and management could be performed. Personal information References Westra C, Dialani V, Mehta TS, Eisenberg RL. Using T2-weighted sequences to more accurately characterize breast masses seen on MRI. AJR Am J Roentgenol. 2014 Mar;202(3):W183-90. Levine PH, Waisman J, Yang GC. Aspiration cytology of cystic carcinoma of the breast. Diagn Cytopathol. 2003 Jan;28(1):39-44. Rinaldi P, Ierardi C, Costantini M, Magno S, Giuliani M, Belli P, Bonomo L. Cystic breast lesions: sonographic findings and clinical management. J Ultrasound Med. 2010 Nov;29(11):1617-26. Berg WA, Sechtin AG, Marques H, Zhang Z. Cystic breast masses and the ACRIN 6666 experience. Radiol Clin North Am. 2010 Sep;48(5):931-87. Berg WA, Campassi CI, Ioffe OB. Cystic lesions of the breast: sonographic-pathologic correlation. Radiology. 2003 Apr;227(1):183-91. D'Orsi CJ, Sickles EA, Mendelson EB, Morris EA et al. ACR BI-RADS Atlas, Breast Imaging Reporting and Data System. Reston, VA, American College of Radiology; 2013 Page 37 of 37