Women’s Imaging • Clinical Perspective

Vashi et al. Imaging of the Pregnant and Lactating Patient

Women’s Imaging Clinical Perspective

Breast Imaging of the Pregnant and Lactating Patient: Physiologic Changes and Common Benign

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Reena Vashi1,2 OBJECTIVE. The purpose of this article is to review key clinical, histologic, and imaging Regina Hooley1 features of expected physiologic changes within the breast and common benign Reni Butler1 in the pregnant and lactating patient. Jaime Geisel1 CONCLUSION. A thorough understanding of expected physiologic changes and common Liane Philpotts1 benign breast abnormalities of pregnancy and lactation is required to differentiate these entities from pregnancy-associated breast cancer and to appropriately guide patient management. Vashi R, Hooley R, Butler R, Geisel J, Philpotts L

he presentation of a pregnant or viding secretory capability to alveolar cells, lactating woman with a palpable which is required for milk synthesis [4]. is a scenario common- Despite the integral role of estrogen and T ly encountered in many breast im- progesterone in preparation for lactation, aging practices. The unique physiologic chang- both inhibit milk production. Colostrum is es that occur within the breast secondary to the secreted into the ductal system in the final hormonal changes of pregnancy and lactation days of pregnancy but at the rate of only a result in increased breast volume and increased few milliliters per day [4]. Milk production water content, with associated palpable nodu- at full capacity begins after childbirth when larity, firmness, and increased parenchymal the stimulatory effects of prolactin act un- density. These changes may make clinical and opposed by the inhibitory effects of placen- radiologic evaluations of the breast difficult. tal estrogen and progesterone [4, 5]. Secre- Eighty percent of patients presenting with tion of prolactin from the pituitary gland a palpable breast mass during pregnancy and steadily increases throughout pregnancy but lactation will have findings of benign disease returns to basal levels postpartum [4]. Milk [1–3]. Successful management of these pa- synthesis is sustained by each breast-feeding tients requires an understanding of expected event, which stimulates biofeedback resulting Keywords: breast imaging, lactation, pregnancy, clinical and imaging findings associated with in high-level intermittent prolactin secretion. pregnancy-associated breast cancer physiologic breast changes and with common Physiologic changes manifest clinically with DOI:10.2214/AJR.12.9845 benign breast disease. increased breast size, firmness, and nodularity, which make the physical examination progres- Received August 28, 2012; accepted without revision Physiologic Changes of Pregnancy sively more difficult as pregnancy advances. September 9, 2012. and Lactation These findings are maintained during lactation Alterations in circulating serum estrogen, and will steadily progress back to the prepreg- 1Department of Diagnostic Imaging, Yale University School of Medicine, New Haven, CT. progesterone, and prolactin levels are pri- nancy state approximately 3 months after ces- marily responsible for the major physiologic sation of breast-feeding. Therefore, a thorough 2Present address: Synergy Radiology Associates, PA, changes during pregnancy and lactation. Be- baseline clinical breast examination at the first 7026 Old Katy Rd, Ste 276, Houston, TX 77024. Address ginning in the first trimester and continuing obstetric visit is recommended [6]. correspondence to R. Vashi ([email protected]). throughout pregnancy, increasing estrogen Changes in breast physiology correlate with CME/SAM levels stimulate growth of the pre- histologic changes seen in the progression from Downloaded from www.ajronline.org by 174.99.42.138 on 01/31/16 IP address 174.99.42.138. Copyright ARRS. For personal use only; all rights reserved This article is available for CME/SAM credit. dominantly through the development and ar- the prepregnancy to postlactation state (Fig. 1). borization of the ductal system and, to a less- Although the histologic appearance of normal AJR 2013; 200:329–336 er extent, through increasing stromal adipose breast parenchyma varies with the menstru- 0361–803X/13/2002–329 tissue [4, 5]. Progesterone acts synergistical- al cycle, lumina are generally collapsed with ly with estrogen to contribute to ductal and the exception of minimal secretions in the lu- © American Roentgen Ray Society lobular growth and is responsible for pro- teal phase [5]. At the alveolar level, during

AJR:200, February 2013 329 Vashi et al.

the first trimester of pregnancy the two-layer nign. A proposed cause of bloody dis- margin, and with or without a few gentle lob- epithelial structure of the prepregnancy state charge includes unnoticed minimal breast trau- ulations [5] (Fig. 5). Fibroadenomas are often is maintained. During the second and third tri- ma in the setting of epithelial proliferation and multiple and bilateral. Ultrasound-guided bi- mesters the superficial layer differentiates into new capillary formation [11]. Although blood opsy should be considered for any new solid a colostrum cell layer with associated eosino- in may not always be clinical- mass in a pregnant or lactating patient despite philic cells, plasma cells, and leukocytes [5]. ly apparent, cytologic analysis showed RBCs a benign ultrasound appearance. Infarcted fi- Throughout pregnancy there is progressive en- were present in 20% of women with nipple dis- broadenomas may show internal cystic spaces largement of the lobules with increasing lumin- charge during pregnancy and 23% of lactat- and a more irregular border than typical fibro- al distention in the second and third trimesters. ing women [10, 12, 13]. Bloody nipple dis- adenomas [7], and these suspicious features Luminal distention is most marked during lac- charge without an associated mass is rarely should prompt biopsy (Fig. 6). In nonpregnant tation and will regress with shrinking lobules seen as a presenting symptom of pregnancy- patients, biopsy-proven fibroadenomas with in the postlactation period. associated breast cancer [10, 14]. slight growth of up to 20% may be safely fol- Several physiologic changes of pregnancy In cases of spontaneous, unilateral bloody lowed with a 6-month follow-up ultrasound and lactation show imaging correlates on ul- nipple discharge in the absence of a palpable examination and may not require rebiopsy trasound examination. Lobular growth is re- mass, ultrasound can be performed to evalu- [17]. The same criteria may also be applied to flected by increased echogenicity of normal ate the retroareolar ducts to exclude a papil- documented preexisting fibroadenomas that breast parenchyma throughout pregnancy. In loma or intraductal carcinoma [11]. Ductog- show growth during pregnancy, but meticu- the final days of pregnancy, tubular hypoecho- raphy can also be safely performed and can lous scanning is necessary to exclude suspi- ic structures are seen, representing colostrum- be considered if cytologic findings are suspi- cious features (Fig. 7). filled ducts (Fig. 2). Colostrum differs from cious and discharge originates from a single postpartum breast milk in that it contains al- duct [10, 11]. Postpartum contrast-enhanced Lactating Adenoma most no fat [4], thus explaining its hypoecho- MRI may also be useful for further workup in Lactating adenomas are seen primarily ic appearance on ultrasound. During lactation, selected cases if clinically indicated [15, 16]. during lactation and the third trimester of most breast parenchyma appears echogenic, pregnancy but may occasionally be observed resulting from the combination of glandular Fibroadenoma in the first and second trimesters of pregnan- enlargement and engorgement of breast tissue The most common benign tumor detect- cy [5, 7]. Lactating adenomas present very with milk rich in fat. In both pregnancy and ed during pregnancy and lactation is a fi- similarly to fibroadenomas as painless, soft, lactation, hypervascularity of the breast tissue broadenoma [11]. Fibroadenomas are usual- mobile masses [7]. They may also become can be observed [7] (Fig. 3). After cessation ly present before pregnancy but may not be infarcted and present atypically as a firm ten- of breast-feeding, the sonographic appearance clinically apparent until they grow under the der mass. A un ique feature of lactating ade- of the breast returns to the prepregnancy state. influence of hormonal stimuli [5] and present nomas is the tendency to regress after cessa- The primary mammographic manifesta- as a “new” or enlarging palpable mass. Fibro- tion of breast-feeding [18]. tion of the physiologic changes of pregnan- adenomas typically present as painless firm, Lactating adenomas differ histologically cy and lactation is increased breast size and mobile, and rubbery masses. Fibroadenomas from fibroadenomas in that they consistent density. These changes may be most pro- may occasionally become infarcted second- predominantly of epithelial elements with a nounced during early lactation and the late ary to rapid growth outpacing the vascular very minimal stromal component [5]. The ep- third trimester (Fig. 4). It may be helpful to supply. Infarcted fibroadenomas may differ ithelial component consists of mature tubules ask the lactating patient to nurse or pump be- from typical fibroadenomas and present as similar to those found in normal lobules. The fore mammography to decrease the density tender nonmobile masses [7]. tubules contain actively secreting cells result- of the engorged breast. Fibroadenomas arise in the terminal ductal ing in acini distended with secretions [7]. MRI performed during lactation will also lobular unit and contain both epithelial and stro- A lactating adenoma may be indistinguish- reflect expected physiologic changes. A case mal components [5, 7]. The epithelial compo- able from a fibroadenoma on sonography (Fig. report of a lactating patient without breast nent consists of glandlike ductal spaces, and the 8). Like fibroadenomas, lactating adenomas cancer and a case series of seven lactating pa- stromal component is made up of connective may be multiple and bilateral. Lactating adeno- tients, five of whom had biopsy-proven breast tissue [5]. Hyalinization, calcification, and os- mas typically appear as oval masses with a wid- cancer, described MRI findings of increased sification of the stromal elements may be seen er-than-tall orientation, posterior acoustic en- background enhancement and of diffusely in- in older lesions in postmenopausal patients but hancement, and a circumscribed margin [7, 18]. creased T2 signal in lactating patients [8, 9]. are atypical in lesions found in the pregnant and A microlobulated margin is often seen; inves- Increased and rapid diffuse breast enhance- lactating patient [5]. Fibroadenomas in preg- tigators have postulated that each microlobula- ment has been attributed to the increased vas- nant and lactating patients occasionally show tion represents an acinus distended with secre- cularity of the lactating breast, and the diffuse secretory hyperplasia or lactational change on tions [7]. The posterior acoustic enhancement increased T2 signal is thought to be second- histologic examination but are generally con- is presumably secondary to the large amount

Downloaded from www.ajronline.org by 174.99.42.138 on 01/31/16 IP address 174.99.42.138. Copyright ARRS. For personal use only; all rights reserved ary to the aqueous nature of breast milk. sidered to be distinct from lactating adenomas. of secretions. Increased lesion compressibility The most common sonographic appearance may be observed, perhaps for the same reason, Bloody Nipple Discharge of fibroadenomas in pregnant and lactating on application of ultrasound probe pressure [7]. Bloody nipple discharge is occasionally en- women is similar to that seen in nongestation- Infarcted lactating adenomas often show atypi- countered during pregnancy, usually during al patients: an oval or round mass with a wid- cal features including posterior acoustic shad- the third trimester [10], and is most often be- er-than-tall orientation, with a circumscribed owing and irregular margins and are thus indis-

330 AJR:200, February 2013 Breast Imaging of the Pregnant and Lactating Patient

tinguishable from other benign and malignant immediately postpartum, and the most like- clinical and imaging features of normal physi- entities [7, 18] (Fig. 9). ly infectious agents are Staphylococcus and ologic changes and of common benign entities Streptococcus bacteria [5, 20]. is required to differentiate these entities from Galactocele Clinically, patients may present with an pregnancy-associated breast cancer. A galactocele is the most common benign edematous, erythematous, and tender breast [5, breast mass in the lactating patient [11]. Ga- 7]. Uncomplicated is a clinical diagno- References lactoceles are most often seen after cessation sis that does not necessitate an imaging work- 1. Woo JC, Yu T, Hurd TC. Breast cancer in preg- of breast-feeding but can also be seen during up. The presence of a fluctuant mass should nancy: a literature review. Arch Surg 2003; 138:91– lactation and occasionally in the third trimes- raise suspicion of an underlying abscess [5]. 98; discussion, 99 ter of pregnancy [7]. Galactoceles most com- Ultrasound should be performed if response 2. Byrd BF Jr, Bayer DS, Robertson JC, Stephenson SE monly present as a painless palpable mass in to antibiotic therapy is poor or if abscess for- Jr. Treatment of breast tumors associated with preg- the weeks or months after cessation of breast- mation is suspected. Sonographic findings in nancy and lactation. Ann Surg 1962; 155:940–947 feeding [7]. In cases that present during lac- early mastitis may be limited to regional edema 3. Collins JC, Liao S, Wile AG. Surgical manage- tation, investigators have observed that the and skin thickening [7]. As tissue necrosis be- ment of breast masses in pregnant women. J Re- patient provides a history of decreased fre- gins in focal mastitis, skin thickening may be prod Med 1995; 40:785–788 quency of nursing [7]. accompanied by a focal hypoechoic mass with 4. Hall JE, Guyton AC. Guyton and Hall textbook of Galactoceles occur as a result of obstruc- surrounding hyperemia. In cases of focal mas- medical physiology, 12th ed. Philadelphia, PA: tion of a duct and inspissation of milk [11]. titis, a focal inflammatory mass may occur and Saunders/Elsevier, 2011 Histologically, the lesion represents milk-dis- mimic the appearance of a solid mass. Careful 5. Harris JR. Diseases of the breast, 3rd ed. Philadel- tended terminal ducts or ductules with normal clinical and ultrasound evaluation and follow- phia, PA: Lippincott Williams & Wilkins, 2004 associated epithelium and myoepithelium [5]. up are necessary to ensure proper diagnosis 6. Gemignani ML, Petrek JA. Pregnancy-associated Galactoceles contain varying amounts of wa- (Fig. 11). The sonographic features of a mature breast cancer: diagnosis and treatment. Breast J ter, protein, fat, and lactose. Enzymes may de- abscess are typically a thick-walled mass and 2000; 6:68–73 nature the milk over time, resulting in coales- posterior acoustic enhancement with or with- 7. Stavros AT. Breast ultrasound. Philadelphia, PA: cence of emulsified lipid droplets into larger out internal gas and debris (Figs. 12 and 13). Lippincott Williams & Wilkins, 2004 globules [7]. Ultrasound-guided aspiration should be con- 8. Talele AC, Slanetz PJ, Edmister WB, Yeh ED, Ko- The sonographic appearance of galactoceles sidered if an abscess is present to provide pain pans DB. The lactating breast: MRI findings and is correspondingly variable and depends on fat relief and to shorten illness duration [5, 7]. If literature review. Breast J 2003; 9:237–240 content and lesion age (Fig. 10). Galactoceles the abscess persists or recurs, repeat aspiration 9. Espinosa LA, Daniel BL, Vidarsson L, Zakhour are usually round or oval; may be anechoic, hy- should be performed for the same reasons [21]. M, Ikeda DM, Herfkens RJ. The lactating breast: poechoic, or echogenic; and may show wall Treatment also includes antibiotic therapy and contrast-enhanced MR imaging of normal tissue thickening in cases of chronic inflammation pain management [20, 22]. If an underlying and cancer. Radiology 2005; 237:429–436 [19]. Galactoceles usually show increasing in- mass is suspected, core needle biopsy should 10. Lafreniere R. Bloody nipple discharge during ternal echogenicity as the lesion ages, and a fat- also be performed [11, 20]. Patients can con- pregnancy: a rationale for conservative treatment. fluid level is occasionally observed [7]. Even in tinue breast-feeding after the biopsy procedure, J Surg Oncol 1990; 43:228–230 cases with internal complex echoes, vascular and it may be helpful to reduce milk stasis and 11. Sabate J, Clotet M, Torrubia S, et al. Radiologic flow should never be present; however, hyper- the likelihood of recurrent abscess [20]. Clini- evaluation of breast disorders related to pregnan- emia may be seen in the adjacent compressed cal follow-up to ensure resolution is required cy and lactation. RadioGraphics 2007; 27(suppl breast parenchyma [7]. in all patients. In atypical or refractory cases, 1):S101–S124 Most galactoceles will regress spontaneous- further imaging with follow-up ultrasound and 12. Kline TS, Lash S. Nipple secretion in pregnancy: ly and will not require aspiration. However, a mammography should be considered [23]. In a cytologic and histologic study. Am J Clin Pathol galactocele may have a sonographic appear- these cases, the decision to perform imaging- 1962; 37:626–632 ance of a complex mass or may be bothersome guided core needle biopsy or skin punch bi- 13. Kline TS, Lash SR. The bleeding nipple of preg- to the patient. In these cases, ultrasound-guid- opsy should be based on the presence of suspi- nancy and postpartum period: a cytologic and ed aspiration can be performed and will yield cious imaging or clinical features. histologic study. Acta Cytol 1964; 8:336–340 milky fluid (Fig. 10). Galactoceles may recur 14. Robbins J, Jeffries D, Roubidoux M, Helvie M. after aspiration and may also occasionally be- Conclusion Accuracy of diagnostic mammography and breast come superinfected; in these cases, aspiration Similar to nongestational patients, most ultrasound during pregnancy and lactation. AJR may be diagnostic and therapeutic [5]. pregnant and lactating patients presenting 2011; 196:716–722 for breast imaging are found to have benign 15. Morrogh M, Morris EA, Liberman L, Borgen PI, Mastitis disease. However, all palpable masses in a King TA. The predictive value of ductography Mastitis with or without abscess formation pregnant or lactating patient that persist for 2 and magnetic resonance imaging in the manage-

Downloaded from www.ajronline.org by 174.99.42.138 on 01/31/16 IP address 174.99.42.138. Copyright ARRS. For personal use only; all rights reserved is commonly seen during lactation and is less weeks or longer should be promptly evaluated ment of nipple discharge. Ann Surg Oncol 2007; frequently seen during pregnancy [5, 11]. The with ultrasound. Biopsy should be considered 14:3369–3377 proposed cause of mastitis is retrograde infec- for any new solid mass identified despite a be- 16. Orel SG, Dougherty CS, Reynolds C, Czerniecki tion through cracked and poor empty- nign appearance. If biopsy is not performed, BJ, Siegelman ES, Schnall MD. MR imaging in ing of milk [5]. The highest incidence of lac- then close imaging and clinical follow-up is patients with nipple discharge: initial experience. tation-related mastitis is during the 6 weeks necessary. A thorough understanding of the Radiology 2000; 216:248–254

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17. Gordon PB, Gagnon FA, Lanzkowsky L. Solid breast 19. Sawhney S, Petkovska L, Ramadan S, Al- es. Breast 2005; 14:375–379 masses diagnosed as fibroadenoma at fine-needle Muhtaseb S, Jain R, Sheikh M. Sonographic ap- 22. Scott-Conner CEH. Diagnosing and managing aspiration biopsy: acceptable rates of growth at pearances of galactoceles. J Clin Ultrasound breast disease during pregnancy and lactation. long-term follow-up. Radiology 2003; 229:233–238 2002; 30:18–22 Medscape Womens Health 1997; 2:1 18. Sumkin JH, Perrone AM, Harris KM, Nath ME, 20. Dixon JM. ABC of breast diseases: breast infec- 23. Trop I, Dugas A, David J, et al. Breast abscesses: Amortegui AJ, Weinstein BJ. Lactating adenoma: tion. BMJ 1994; 309:946–949 evidence-based algorithms for diagnosis, man- US features and literature review. Radiology 21. Eryilmaz R, Sahin M, Hakan Tekelioglu M, Dal- agement, and follow-up. RadioGraphics 2011; 1998; 206:271–274 dal E. Management of lactational breast abscess- 31:1683–1699

A B

C D Fig. 1—Photomicrographs (H and E; ×40). A, Normal breast tissue in 25-year-old woman who is not pregnant shows lobules with collapsed lumina, dense stroma, and mononuclear infiltrate. B, Normal breast tissue in 33-year-old pregnant woman shows extensive lactational changes. During pregnancy, lobules increase at expense of interlobular adipose tissue. Lumina are open with eosinophilic secretions. C, Normal breast tissue in 29-year-old woman 2 weeks postpartum shows lobules markedly distended with secretions and vacuolated cytoplasm in epithelial cells. D, Normal breast tissue in 27-year-old woman after cessation of breast-feeding shows lobules have begun to shrink; mononuclear infiltrate is commonly found in intralobular stroma. Downloaded from www.ajronline.org by 174.99.42.138 on 01/31/16 IP address 174.99.42.138. Copyright ARRS. For personal use only; all rights reserved

332 AJR:200, February 2013 Breast Imaging of the Pregnant and Lactating Patient

Fig. 2—30-year-old woman, 40 weeks pregnant, with bloody nipple discharge. Gray-scale ultrasound image shows prominent hypoechoic ducts filled with colostrum and no underlying mass. Because colostrum contains very little fat, ductal secretions are hypoechoic.

A B Fig. 3—37-year-old lactating woman with palpable breast mass. A, Gray-scale ultrasound image shows markedly echogenic breast tissue and no underlying mass. These findings are normal in lactating patients and are due to engorged, milk-filled breasts. B, Color Doppler ultrasound image shows generalized hypervascularity, also normal in lactating patients. Downloaded from www.ajronline.org by 174.99.42.138 on 01/31/16 IP address 174.99.42.138. Copyright ARRS. For personal use only; all rights reserved

Fig. 4—Bilateral mammograms of 36-year-old breast- feeding woman. A and B, Images show breasts are extremely dense. A B

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Fig. 5—37-year-old woman, 7 weeks pregnant, with new palpable right breast mass that was noted to be simple cyst on ultrasound image not adjacent to this solid well-circumscribed incidentally seen oval hypoechoic mass, consistent with fibroadenoma. Although this mass was not biopsied; short-interval ultrasound follow-up was advised because of benign ultrasound features and patient’s history of two prior palpable biopsy-proven right breast fibroadenomas.

A B Fig. 6—28-year-old pregnant woman in first trimester of first pregnancy with rapidly enlarging 7-cm palpable breast mass. A, Targeted gray-scale ultrasound image shows oval circumscribed heterogeneous mass with small cystic components. B, Color Doppler ultrasound image shows internal and predominately peripheral vascularity. These findings are consistent with infarcting fibroadenoma, but malignancy cannot be excluded. Ultrasound-guided core needle biopsy showed fibroadenoma without infarction. Lack of infarction was likely secondary to undersampling.

Fig. 7—29-year-old woman, 32 weeks pregnant, referred for short-interval follow- Fig. 8—37-year-old woman, 37 weeks pregnant, with palpable right breast mass. up of palpable biopsy-proven fibroadenoma in left breast. Gray-scale ultrasound Targeted gray-scale ultrasound image shows oval well-circumscribed hypoechoic Downloaded from www.ajronline.org by 174.99.42.138 on 01/31/16 IP address 174.99.42.138. Copyright ARRS. For personal use only; all rights reserved image shows oval predominately echogenic mass with indistinct margins. mass; these features are characteristic of fibroadenoma. Mass proved to be Mass had also increased from 1.9 × 1.1 × 1.9 cm to 2.7 × 1.7 × 2.5 cm. Because lactating adenoma on ultrasound-guided core needle biopsy. this increase is greater than 20% and margins was not circumscribed, surgical excisional biopsy was performed; results confirmed diagnosis of fibroadenoma.

334 AJR:200, February 2013 Breast Imaging of the Pregnant and Lactating Patient

A B Fig. 9—23-year-old pregnant woman who presented during third trimester with bilateral painful palpable masses. A, Gray-scale ultrasound image shows large (> 5 cm) oval heterogeneous hypoechoic mass in right upper outer quadrant. B, Ultrasound image of left breast shows heterogeneous predominately hypoechoic mass that is more irregularly shaped than but otherwise similar to mass shown in A. Although these findings may be seen with infarction, malignancy cannot be excluded. Ultrasound-guided core needle biopsy confirmed bilateral lactating adenomas.

A B

C D Fig. 10—Multiple galactoceles with variable appearances on gray-scale ultrasound images.

Downloaded from www.ajronline.org by 174.99.42.138 on 01/31/16 IP address 174.99.42.138. Copyright ARRS. For personal use only; all rights reserved A, 28-year-old breast-feeding woman who presented with painful new mass in left breast. Targeted ultrasound image shows lobulated predominately anechoic galactocele with high water content and small amount of echogenic fat (arrow). B, 31-year-old woman, 3 months postpartum, with new palpable right breast mass. Targeted ultrasound image shows predominately echogenic mass with fat-fluid level consistent with galactocele with high fat content. C, 33-year-old breast-feeding woman with anechoic galactocele with high water content and subtle fat-fluid level arrow( ). D, 28-year-old breast-feeding woman with recurrent painful mass 3 weeks after aspiration of galactocele. Ultrasound shows complex mixed echogenicity oval mass with thick wall, consistent with recurrent galactocele. Ultrasound-guided biopsy revealed lactational breast tissue with acute and chronic inflammatory changes.

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Fig. 11—37-year-old lactating woman with focally painful, palpable left breast mass. Gray-scale ultrasound image shows irregular heterogeneous mass with mixed echogenicity and indistinct margins (arrow). Diagnosis of focal mastitis was made, biopsy was not performed, and antibiotic therapy was instituted. Follow-up ultrasound performed 1 week after completion of antibiotics (not shown) showed resolution of mass.

A B C Fig. 12—37-year-old woman, 1 month postpartum and breast-feeding, who presented with left , palpable mass, and fever. A, Skin thickening and edematous hypervascular breast on color Doppler ultrasound as shown are consistent with mastitis. B, Palpable lump corresponded to this complex cystic mass on ultrasound, which is consistent with breast abscess. C, Thirty-five milliliters of thick fluid was aspirated under ultrasound guidance using 18-gauge needle. Patient was treated with antibiotics.

A B Fig. 13—18-year-old pregnant woman with right breast erythema and induration. A, Ultrasound image shows complex cystic mass. Note echogenic air with dirty shadowing (arrow) within mass. B, Color Doppler ultrasound image shows marked peripheral hypervascularity. These findings are consistent with abscess.

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336 AJR:200, February 2013