The premammary layer at breast sonography imaging: normal appearance and disease with mammography correlation

The premammary layer at breast sonography imaging: normal appearance and disease with mammography correlation Poster No.: C-0250 Congress: ECR 2012 Type: Educational Exhibit Authors: A. Fariña; Bilbao/ES Keywords: Breast, Soft tissues / Skin, Ultrasound, Mammography, Efficacy studies, Pathology DOI: 10.1594/ecr2012/C-0250 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 31

Learning objectives Describe the ultrasound anatomy of the skin and subcutaneous fat. Recognize the ultrasound findings in dermal breast pathology. Correlate with mammography imaging findings. Background ANATOMY Breast sonography allows a direct visualization of the premammary layer. It represents the superficial layer, between the skin and the anterior mammary fascia behind which lye the mammary layer with the breast parenchyma. Fig. 1 The anterior fascia appears as an echogenic line, somewhat wavy. Fig. 2 Its posterior shift is useful in locating a lesion in the premammary layer. Fig. 3 It contains fatty tissue, Cooper ligaments, blood vessels and, sometimes terminal ductolobulillar units ( TDLU ) entrapped between the suspensory ligaments. Fig. 4 At US imaging we can recognize 3 layers Fig. 5 : - a thin echogenic line representing accoustic gel. Epidermis intefase. - a 2-4mm. strip, first hypoechoic and echogenic in depth representing the dermal layer. - a hypoechogenic layer or subcutaneous fat representing the hypodermal layer. This level remains consistently hypoechoic in all women, that is isoechogenic with fat. It thickness increases with glandular parenchyma involution. PATHOLOGY Fig. 6 Page 2 of 31

We can found any primary pathology arising in the skin and subcutaneous fat at the premammary layer and it is important to recognize their superficial localization at breast imaging because they usually represent benign lesions : sebaceous cyst, epidermal inclusion cyst, hematoma, fat necrosis, hemagioma, thrombosed vessel, lymph node. Secondarily the premammary layer can be affected in diseases that course with anasarca(chronic liver disease, chronic renal failure or right heart failure), in lymphedema or in mastitis or ductal carcinoma that infiltrates the subcutaneous layer. Images for this section: Fig. 1: BREAST US ANATOMY : premammary,mammary and retromammary layers separeted from each other by the anterior and posterior fascias. Page 3 of 31

Fig. 2: ANTERIOR MAMMARY FASCIA : POSTERIOR BOUNDARY OF THE PREMAMMARY LAYER Page 4 of 31

Fig. 3: DISPLACEMENT OF THE ANT. MAMMARY FASCIA : a usefull hallmark to assess the localization of a lesion. Page 5 of 31

Fig. 4: THE PREMAMMARY LAYER CONTENTS: Cooper ligaments are in continuity with the ant, mammary fascia. Page 6 of 31

Fig. 5: SKIN AND SUBCUTANEOUS FAT HISTOLOGY : THE US IMAGING LAYERS Page 7 of 31

Fig. 6: PREMAMMARY LAYER PATHOLOGY Page 8 of 31

Imaging findings OR Procedure details At mammography the lesions arising in the skin and subcutaneous fat could appear as masses not always circumscribed and sometimes increasing in size, as focal asymetry or as dermal thickening. In this way, the ultrasound findings improve the correct localization of a superficial breast lesion. DERMAL CYST : SEBACEOUS CYST : they arise in the dermis and can expand to the subcutaneous fat. The anterior fascia is pushed downward and displaced posteriorly and the "claw sign" is present Fig. 7 on page 12. This sign represents the hyperechoic dermal tissue invaginating around the margins. It is helpful to look for the " tract to skin" representing the extension of the hair follicle from the dermis up through the epidermis, confirming a dermal origin Fig. 8 on page 13. But with chronic course this tract closes and disappears. Their internal echotexture is variable ranging from cystic to hyperechogenic depending on its contents. They can become inflamed, showing thick walls, increased vascularization and hyperechogenicity of the adyacent tissue. Fig. 9 on page 13 EPIDERMAL INCLUSION CYST : They appear like the sebaceous cysts, but as opposed to them, they contain keratinous material with a characteristic lamellated or onion-ring internal appearance. The keratinous debris can create a central nodule surrounded by fluid (pearl aspect), that can calcificate (posterior shadowing) or with echogenic strands of keratine to the wall (fibrous aspect). CAVERNOUS HEMANGIOMA Fig. 11 on page 15 It is a rare vascular tumor in the breast. Usually they are not palpable because they are easily compressed. At mammography they appear as circumscribed macrolobulated masses, sometimes with amorphous calcifications (not round, like phleboliths in other anatomical locations). At ultrasound imaging they manifest as hyperechogenic masses, heterogeneous, that become compressed with transducer pression. HEMATOMA Page 9 of 31

It results from the extravasation of blood secondary to traumatic or iatrogenic injury or anticoagulant therapy. It may be subcutaneous or extend through the subcutaneous fat to the breast parenchyma depending on the extent of injury. The internal echotexture is variable within time ranging from cystic in acute to more solid and complex mass Fig. 12 on page 16. Usually it contains blood products in different phases of coagulation so, it is difficult to determine the different clot phases. The adjacent tissue can develop fat edema (chemical mastitis) Fig. 13 on page 17 or equimosis (cellulitis). FAT NECROSIS Usually a history of traumatism, surgery, radiation therapy, or an obese woman with pendulous breast is reported. Sometimes it can manifest as a clinically palpable mass or painful lump. There is a destrution of fat cells releasing fatty acids that act as chemical irritants, with inflammation of the surrounding tissue. With time, it can encapsulate and appear as a lipid cyst or a foreign body response develops with fibrosis. Imaging features depend on the time and form of progression. In this way, ultrasonography findings vary with the extent of the fibrotic response as follow : -increased echogenicity of the subcutaneous fat, with or without a small cyst. Fig. 14 on page 18 Fig. 15 on page 19 -anechogenic mass. -solid mass. -cystic mass with internal debris or mural nodules. The presence of internal echogenic strips adjustable with change in position is a characteristic ultrasound finding of fat necrosis, representing the lipidic-serosanguineous interphase. EDEMA, LYMPHEDEMA, MASTITIS AND INFLAMMATORY CARCINOMA There is a diffuse thickening of the skin and subcutaneous tissue, with increase of the echogenicity and loss of differenciation between dermis and hypodermis. The clear visualization of the Cooper ligaments decreases, and it is possible to find fluid sheets along them. Generally there is a global decrease in ultrasound wave transmission. Fig. 16 on page 20 Fig. 17 on page 21 Fig. 18 on page 22 MORPHEA Page 10 of 31

Uncommun disease representing a focal form of cutaneous sclerodermia, and sometimes in association with autoinmune disease and radiotherapy. A dermal infiltrate occurs activating fibroblastic reaction with connective tissue and fat subcutaneous atrophy. The epidermis may not be affected. At US imaging the atrophy of the subcutaneous fat is evident, identifying a hyperechogenic tissue that results indistinguishable from interlobular fibrous tissue, losing the characteristic laminate appearance of the layers premmary-mammary. Fig. 19 on page 23 Fig. 20 on page 24 MONDOR DISEASE It is a vascular disease representig an acute thrombosis of the superficial subcutaneous veins. History of surgery or direct injury is reported, and is typically associated with seatbelt injury. Also it is related with exertion and dehydration. At US the imaging of a tubular cystic structure not compressed under pressure is characteritic Fig. 21 on page 25, with more tortuous veins the US appearance is more nodular like a "string of pearls". FLUId SILICONE SUBCUTANEOUS INJECTION It is an unapproved modality for breast augmentation that impedes mammographic screening and ultrasound evaluation. The US imaging shows the silicone gel like a snowstorm due to a dirty hyperechogenicity. There is an important thickening of the dermis and loss of the subcutaneous fat with granulomas formation. Fig. 22 on page 26 SECONDARY INFILTRATION OF DUCTAL CARCINOMA The triangular shape of the Cooper ligaments represents a low resistance pathway for the growth of an invasive carcinoma located along the posterior aspect of the premammary fascia, and therefore the skin can be affected. Fig. 23 on page 27 ANATOMY Breast sonography allows a direct visualization of the premammary layer. It represents the superficial layer, between the skin and the anterior mammary fascia behind which lye the mammary layer with the breast parenchyma. Fig. 1 The anterior fascia appears as an echogenic line, somewhat wavy.fig. 2 Its posterior shift is useful in locating a lesion in the premammary layer. Fig. 3 Page 11 of 31

It contains fatty tissue, Cooper ligaments, blood vessels and, sometimes terminal ductolobulillar units ( TDLU ) entrapped between the suspensory ligaments. Fig. 4 At US imaging we can recognize 3 layers Fig. 5 : - a thin echogenic line representing accoustic gel. Epidermis intefase. - a 2-4mm. strip, first hypoechoic and echogenic in depth representing the dermal layer. - a hypoechogenic layer or subcutaneous fat representing the hypodermal layer. This level remains consistently hypoechoic in all women, that is isoechogenic with fat. It thickness increases with glandular parenchyma involution. PATHOLOGY Fig. 6 We can found any primary pathology arising in the skin and subcutaneous fat at the premammary layer and it is important to recognize their superficial localization at breast imaging because they usually represent benign lesions : sebaceous cyst, epidermal inclusion cyst, hematoma, fat necrosis, hemagioma, thrombosed vessel, lymph node. Secondarily the premammary layer can be affected in diseases that course with anasarca(chronic liver disease, chronic renal failure or right heart failure), in lymphedema or in mastitis or ductal carcinoma that infiltrates the subcutaneous layer. Images for this section: Page 12 of 31

Fig. 7: THE CLAW SIGN IN A SEBACEOUS CYST Fig. 8: THE TRACT TO SKIN SIGN IN A SEBACEOUS CYST Page 13 of 31

Fig. 9: INFLAMMATION OF A SEBACEOUS CYST : US IMAGING FEATURES Page 14 of 31

Fig. 10: EPIDEMAL INCLUSION CYST Page 15 of 31

Fig. 11: CAVERNOUS HEMANGIOMA IN A SUBCUTANEOUS LOCATION Page 16 of 31

Fig. 12: CHRONIC HEMATOMA at us imaging a solid mass in a superficial location is seen Page 17 of 31

Fig. 13: hematoma with chemical necrosis: surrounding fat appears hyperechogenic at US imaging Page 18 of 31

Fig. 14: FAT NECROSIS : subcutaneous fat appears hyperechogenic with a central nodule. Page 19 of 31

Fig. 15: FAT NECROSIS : subcutaneous fat is hyperechogenic Page 20 of 31

Fig. 16: SUBCUTANEOUS EDEMA IN CHRONIC RENAL FAILURE Page 21 of 31

Fig. 17: UNILATERAL LYMPHEDEMA in a woman with chronic renal failure and a arteriovenous fistula in her left arm. Page 22 of 31

Fig. 18: INFLAMMATORY CARCINOMA Page 23 of 31

Fig. 19: LOCALIZED CUTANEOUS SCLERODERMA ON THE RIGHT BREAST: complete atrophy of the subcutaneous fat. Page 24 of 31

Fig. 20: LOCALIZED CUTANEOUS SCLERODERMA ON THE RIGHT BREAST: complete atrophy of the subcutaneous fat. Page 25 of 31

Fig. 21: SUPERFICIAL VEIN THROMBOSIS : THE VEIN DON T COLLAPSE Page 26 of 31

Fig. 22: SUBCUTANEOUS SILICONE INJECTION : at US imaging the "snow storm" silicone characteristic appearance. Page 27 of 31

Fig. 23: CUTANEOUS SECONDARY INVASION FROM A INFILTRATIVE CARCINOMA IN THE MAMMARY LAYER. Page 28 of 31

Conclusion Breast sonography plays an important role in evaluation of mammographic lesions such as masses and focal asymmetries, identifying fairly accurately their location; so that lesions arising in the premammary layer may be managed within the diagnostic categories BIRADS 2 or 3, very confidently and can prevent more aggressive options. Fig. 24 on page 29 Fig. 25 on page 30 When there is an increase in thickness of the skin and subcutaneous fat the US imaging provides more information about extent, presence of cellulitis and other associated findings. Breast US remains a useful tool in staging an infiltrative carcinoma, allowing a direct visualization of the secondary cutaneous invasion for adequate therapeutic planning. Images for this section: Page 29 of 31

Fig. 24: MAMMOGRAPHY : SUPERFICIAL FOCAL ASSYMETRIES IN TWO DIFFERENT WOMEN ONE (case 1) ASYMPTOMATIC AND THE OTHER ONE (case2)with a palpable nodule Fig. 25: Case 1. = sebaceous cyst with air (BIRADS 2) Case 2. = infiltrative ductal carcinoma with subcutaneous invasion (BIRADS 5 ) Page 30 of 31

Personal Information References 1. A.Thomas Stavros. ECOGRAFIA DE MAMA.Ed.Marban 2. Dra Carolina Whittle P, TM. Gina Baldasare P. ULTRASONOGRAFIA DE PIEL Y ANEJOS 3. J.M.Fernandez Vozmediano,J.C.Armario Hita y A.Escribano Moriana. UTILIDAD DE LA ECOGRAFIA CUTANEA EN DERMATOLOGIA.Piel;18(10):564-73. 4. Hyeon Sook Kim,MD,Eun Suk Cha,MD,Hak Hee Kim,MD and Jin Young Yoo,MD.SPECTRUM OF SONOGRAPHIC FINDINGS IN SIUPERFICIAL BREAST MASSES.J.Ultrasound Med.2005.24:663-680. 5. Sun Yang Chung,MD and Ki Keun Oh,MD.MAMMOGRAPHIC AND SONOGRAPHIC FINDINGS OF A BREAST SUBCUTANEOUS HEMANGIOMA. J.Ultrasound Med.2002.21:585-588. 6. Jorge L. Taboada,Tanya W.Stephens,Savitri Krishnamurthy,Kathleen R.Brant and Gary J. Whitman.THE MANY FACES OF FAT NECROSIS IN THE BREAST.ajr 2009;192:815-825. 7. E.Operé, L.Oleaga,T.Ibañez y D.Grande.LOCALIZED SCLERODERMA OF THE BREAST.Eur.Radiol.(2002)12:1483-1485. Page 31 of 31