Silicone Granulomas

MLO mammographic view of the left breast shows diffuse, markedly increased breast density throughout from prior direct silicone injection for breast augmentation. 

Transverse view of ultrasound of the left breast shows a cystic lesion (arrow) and multiple several lesions that has ill-defined borders and posterior acoustic shadowing (short arrows), representing silicone granulomas.

Axial non contrast CT shows multiple isodense soft tissue nodules in both breasts, some with thin rim of calcifications. 

Breast Augmentation with Direct Silicone Injection

• Was done in the USA in 1950s to 1960s but later prohibited in 1970s by the US FDA
• Liquid form of silicone was directly injected into breast parenchyma
• Adverse effects include lymphadenopathy, infection, formation of granulomatous masses (siliconoma) and fibrosis
• They make cancer difficult to find on physical examination and mammography 

Imaging Appearance of Free Silicone

• Ultrasound: variable appearance including 1) classic = highly echogenic pattern of scattered and reverberating echoes or "snowstorm" appearance, 2) lesion with acoustic shadowing, 3) hypoechoic masses almost indistinguishable from cysts surrounded by echogenic noise
• Mammography: distortion of breast parenchyma with increase density of the breast
• CT: soft tissue nodules with rim calcification
• MRI: low signal intensity on T1W with fat suppression, high signal intensity on T2W with water-suppression

Reference:

Caskey CI et al. Imaging spectrum of extracapsular silicone: correlation of US, MR imaging, mammographic and histopathologic findings. RadioGraphics 1999;19:S39-S51

Screening Mammography Overdiagnoses Breast Cancer?

The recently published NEJM's original article describes effect of screening mammography on breast cancer incidence in the USA. Bleyer A and Welch HG. N Eng J Med 2012;367:1998 (22 Nov 2012)

Facts: Aim of Cancer Screening

• We expect cancer screening program to lower cancer-related mortality by a means of 1) earlier detection of disease destined to be fatal and 2) early Rx of screen-detected cancers
• A cancer screening program should 1) increase incidence of cancer detected at an earlier stage and 2) decrease incidence of cancer presenting at a late stage

What Study Is About And What It Has Found:

• Breast cancer rate from 1976 through 1978 (mammography was uncommon) ~ baseline incidence
• Breast cancer rate from 2006 through 2008 ~ current incidence
• Confounding effects of menopausal hormone therapy were minimized by not including transitory increase in incident breast cancers from 1990 through 2005. Underlying incidence of breast cancer assumed to rise by 0.25% annually
• Number of cases of early-staged breast cancer rises from 112 to 234 cases per 100,000 women
• Number of cases of late-staged breast cancer decreases from 102 to 94 cases per 100,000 women
• "With an assumption of a constant underlying disease burden, only 8 of the 122 additional early-stage cancers diagnosed were expected to progress to advanced disease." This was estimated that breast cancer was overdiagnosed. In 2008, the overdiagnosis would account for 31% of all breast cancer diagnosed

Other Studies Said?

Results of this study concur with other reports (references 2-3) and suggest that improvements in treatment are the main drive in reducing breast cancer mortality - rather than screening mammography. 

It is suggested that "pros and cons of mammography should be incorporated into the counseling that women receive as they decide whether an when to be screened". 

References:

1. Bleyer A and Welch HG. Effect of three decades of screening mammography on breast cancer incidence. N Eng J Med 2012;367:1998
2. Kalager M et al. Effect of screening mammography on breast cancer mortality in Norway. N Eng J Med 2010;363:1203
3. Autier P et al. Breast cancer mortality in neighbouring European countries with different levels of screening but similar access to treatment: trend analysis of WHO mortality database. BMJ 2011;343:d4411
4. Kaunitz AM. Screening mammography: does overdiagnosis overshadow prevention of advanced breast cancer? Journal Watch Women's Health November 21, 2012

PET/CT and Breast Cancer

A coronal fused PET/CT image shows a large right breast mass with a ring-like FDG uptake (arrows).

Performance of PET in Breast Cancer

• Sensitivity 89%, specificity 80%
• Sensitivity highly depends on tumor size and grade. Unlikely to pick up tumor less than 0.5 cm, low chance of detecting tumor less than 1 cm
• PET is less sensitive but more specific than MRI for characterizing and detecting breast lesions

Pearls

• Any focal abnormal uptake of FDG should undergo further work-up (irrespective of its standardized uptake value). Note that breast cancer, in general, has lower metabolic activity than most other malignancies
• Incidentally detected breast abnormality on PET has high likelihood of malignancy
• Delayed/dual time point imaging increases sensitivity and accuracy of PET. Tumors accumulate FDG over time (normal breast tissue will not)

Differential Diagnosis of Focal FDG Uptake in the Breast

• Inflammatory: abscess, soft tissue inflammation, TB, sarcoidosis
• Trauma: post-biopsy, hematoma, seroma
• Benign neoplasms: ductal adenoma, fibrous dysplasia, fibroadenoma (rare)

Our case: spindle cell sarcoma of the breast.

Reference:

Lin EC, Alavi A. PET and PET/CT a clinical guide, 2nd edition, 2008.

Ultrasound Features of Malignant Breast Mass

An ultrasound image shows an irregular solid mass with malignant features including ill-defined border, microlobulations, spiculations (seen as hyperechoic band around the mass), taller than wide and angular margin. This was confirmed to be invasive ductal carcinoma at biopsy.

US Features of Malignant Breast Mass

• Marked hypoechogenicity
• Spiculation: highest positive predictive value for malignancy
• Taller than wide
• Angular margin
• Shadowing
• Microlobulation
• Duct extension
• Calcifications
• Branch pattern

Reference:

Cardenosa G. Breast imaging companion, 2nd edition, 2000.

Mammography Quality Control

Facts

• In the US, the Food and Drug Administration (FDA) developed the Mammography Quality Standard Act (MQSA) requiring all mammography facilities to be "certified" (currently there are more than 10,000 facilities)
• The MQSA became effective since April 1999
• It is against federal law to practice mammography without certification by FDA
• To obtain "certification" by the FDA, the facility must be "accredited" by an approved body such as the American College of Radiology (ACR)

What Are Accreditation Requirements of the ACR?

• Requires combined effort of physicians, technologists and medical physicists
• Physician requirements: all interpreting physicians must participate in medical outcome audit, have documentation that they have interpreted at least 200 mammograms in the previous 24 months, ensure qualification of technologist training, assign one technologist to oversee Quality Control (QC) program, assign one physicist to perform annual testing and select one individual to oversee the radiation protection program
• Technologist requirements: QC program is performed on different aspects of mammography on a daily, weekly, monthly, quarterly and semiannual basis. For example, processor QC is performed daily.
• Physicist requirements: medical physicists must be trained in mammography, perform at least 6 annual medical physics surveys every 2 years and receive the required CME credits; image quality, equipments and patient dose are assessed by medical physicists
• ACR phantom is used to check image quality; to pass the test, the phantom image must show a minimum of 4 fibers, 3 speck groups and 3 masses (out of 6 fibers, 5 speck groups and 5 masses on the phantom) and image artifacts are minimal
• Average glandular dose (AGD) for a 4.2 cm thick breast should be less than 3 mGy per image with a grid. If there is no grid, AGD should be less than 1 mGy per image

Author's Notes

• In a new era of quality-minded health care, it is inevitable that medical practice will be increasingly overseen by the public, government and other non-medical authorities. In the case of MQSA, the FDA gives credits to the ACR for certification of each facility.
• It is important for us not only to do best at our routine interpretative work, but also to get involve in quality procedures in the department and professional society. This will help ensure that we serve our patients well and we are the one who will define our own destiny.

Reference:

Huda W. Review of Radiologic Physics, 3rd edition, 2009.

Image credit: www.gammex.com

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Multiple Well-Defined Soft-Tissue Opacities in the Breasts

Mediolateral oblique mammogram of both breasts show multiple, innumerable, well-defined soft-tissue opacities (arrows) and enlarged nipples in a 40-year-old woman.

Differential Diagnosis

• Cysts
• Fibroadenomas: 10-20% are multiple
• Skin lesions: such as neurofibromas
• Intramammary lymph nodes
• Metastasis: melanoma (most common), lymphoma (2nd most common), lung, ovary, soft tissue sarcoma (breast metastasis has a very poor prognosis)

Our case: neurofibromatosis

Reference:

Davies SG. Chapman & Nakielny's Aids to radiological differential diagnosis, fifth edition, 2009.

Ductal Carcinoma in Situ

Magnification mammography shows two separate foci of pleomorphic microcalcifications (arrows) in the left breast. There is no associated mass, architectoral distortion or lymphadenopathy.

Facts: Malignant Calcifications on Mammography

• Small -- less than 0.5 mm
• Clustered, segmental
• Character -- fine granular, fine linear, branching (casting) or pleomorphic

Ductal Carcinoma in Situ (DCIS)

• Malignant ductal epithelium without disruption of the underlying basement membrane; normal ductal architecture is preserved.
• Pathological distinguishing feature from lobular CIS is the presence of intercellular cohesion
• Thought to represent early stage of breast cancer
• Several types: comedo, solid, cribiform, clinging (flat-type), mixed
• Grading based on nuclear atypia and necrosis is predictive of prognosis
• Patients are usually asymptomatic

Mammographic Findings

• Cluster(s) of malignant microcalcifications
• If an area of calcifications is larger than 2.5 cm, high likelihood of microinvasion
• If seen with a mass, it could be an intraductal component of an invasive cancer that may require surgical removal and specimen radiography to ensure complete removal
• Mammography should be thoroughly evaluated for multicentric (tumors in different breast quadrants) and multifocal (same quadrant) disease

Our case: Ductal carcinoma in situ, multifocal disease

References:

1. Kopans DB. Breast imaging, 3rd ed, 2007.

2. Conant EF, Brennecke CM. Breast imaging case review series, 2nd ed, 2006.

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Posterior Acoustic Features of Breast Mass

Transverse ultrasound image of the breast shows an irregularly shaped hypoechoic mass (between calipers) with posterior attenuation of the acoustic transmission ("shadowing"). The shadowing obscures the posterior margin of the mass.

Posterior Acoustic Features

• Attenuation characteristics of a mass with respect to its acoustic transmission
• Four patterns: no posterior acoustic features, enhancement, shadowing and combined

Posterior Shadowing

• Attenuation of sound beam deeper to a mass
• Associated with fibrosis, with or without underlying carcinoma
• DDx: scars, fibrous mastopathy and cancer with desmoplastic response
• Helpful feature when present (suggesting above diagnoses)
• Should be distinguished from "refraction or edge shadowing" which is a thin shadow seen at the edges of curved masses that is of no significance

Our case: invasive ductal carcinoma

Reference:

Madjar H, Mendelson EB. The practice of breast ultrasound, 2nd edition, 2008.

An Expert's Response to the Recent USPSTF Recommendations for Mammography

A recent release of the US Preventive Services Task Force (USPSTF) recommendations for breast cancer screening has brought about so many controversies. Below is the summary view of Dr. Daniel B. Kopans, a Mass General radiologist and Harvard professor, internationally known as a breast imaging expert:

Mass General Imaging believes that the USPSTF recommendations are based on flawed analysis of the data and continues to support the scientifically based recommendations of the American Cancer Society for the early detection of breast cancer:

1. Annual mammographic screening should begin at age 40
2. Women at high risk for developing breast cancer should have annual MRI screening in addition to mammography

View full article by Dr. Kopans (MGH Radiology Rounds) HERE

Read more controversies in the New York Times and Washington Post

Read where the American College of Radiology stands

Additional opinions from the New England Journal of Medicine (November 25, 2009)
- Screening mammography and the "R" word
- On mammography - more agreement than disagreement

Updated Recommendation for Breast Cancer Screening

The update of the U.S. Preventive Services Task Force (USPSTF) recommendation statement on screening for breast cancer in the general population has been published today in the Annals of Internal Medicine.

The USPSTF Recommends

• Against routine screening mammography in women aged 40-49 years
• Biennial (every two years) screening mammography for women between the ages of 50 and 74 years

Based on the USPSTF review, the current evidence is insufficient to assess benefits and harms of ...

• Screening mammography in women 75 years or older
• Clinical breast examination beyond screening mammography in women 40 years or older
• Either digital mammography or magnetic resonance imaging instead of film mammography as screening modalities for breast cancer

What Has Changed from the Previous Recommendations, and Why?

• Recommendations against universal screening mammography for women aged 40 to 49 years, based in part on an updated systematic review of screening mammography randomized, controlled trials that showed lower yield of reduced breast cancer mortality and higher false-postive results with screening in this population
• Recommendation of biennial screening mammography for women aged 50 to 69. Based on statistical models, annual versus biennial screening showed similar degree of breast cancer mortality reduction and similar likelihood of late-stage disease at diagnosis.
• Extension of screening mammography to women aged 70 to 74 years. Models estimate that approximately 2 additional breast cancer deaths are averted per 1000 women screen at this age.

Read full text here (free)

Reference:

1. U.S. Preventive Services Task Force. Screening for breast cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2009;151:716-726.

2. Kerlikokowske K. Evidence-based breast cancer prevention: the importance of individual risk. Ann Intern Med 2009;151:750-752.

Unilateral Opacity of a Hemithorax

Figure 1: Supine chest radiograph shows a unilateral increased opacity in the left hemithorax, particularly at the mid to lower zones. There is no mediastinal shift. The left hemidiaphragm is in a normal position.

Differential Diagnosis

1. Lung: consolidation, mass, collapse
2. Pleura: effusion (layering or loculated), mass (metastasis, mesothelioma)
3. Chest wall: mass (breast, chest wall musculatures)
4. Extrathoracic: external structures

In this case, the opacity extends beyond the lung to the soft tissue of the chest wall, corresponding to the breast. It is unlikely to be a lung lesion because normal pulmonary vasculatures are visualized through it. Pleural lesion would not extend beyond the thoracic cage. Two main possibilities include a large breast mass or external structures (for example, nonradiopaque pads on the bed).

Comparison with the previous chest radiographs revealed that this is a new finding. Further query of patient's history confirmed the diagnosis of a large left breast mass. Chest CT scan (below) also shows the mass (invasive cancer).

Reference:

Chapman S and Nakielny R. Aids to radiological differential diagnosis. 4th edition, 2003.

Breast Hematoma

Fig. 1&2: Ultrasound of the right breast of a 79-year-old woman with a lump shows a mass with a fluid-fluid level (between arrows). The more dependent 'debris' appears to be more echogenic than the non-dependent fluid. There is no color flow within the mass.
Fig. 3: CT scan without IV contrast showed a large mass, again with a fluid-fluid level. The denser portion of the mass measured 60 HU, consistent with blood clot. The scan also revealed a markedly enlarged left atrium. The patient is on anticoagulant therapy for chronic atrial fibrillation.

Facts:

• Common causes: post procedure (biopsy, surgery), direct trauma, coagulopathy
• Breast hematoma occurs in approximately 2% - 10% after breast surgery
• Risk factors: use of some medications (aspirin, NSAIDs, anticogulants)

US Findings:

• Depends on stage of blood product
• Clotted blood appears echogenic, lysed blood (serum) appears cystic.
• No internal flow

Our case - follow up ultrasound was performed and the mass has evolved into a lysed hematoma and then disappeared. Diagnosis was breast hematoma related to anticoagulant use.

Reference:

Vitug AF, Newman LA. Complications in breast surgery. Surg Clin N Am 2007;87:431-451.

Breast Mass in a Pregnant Woman

Fig.1 Ultrasound at 4 o'clock of the right breast shows a 2-cm solid-appearing mass (arrows) with posterior acoustic enhancement (arrowheads) in a young pregnant woman who had breast tenderness for several weeks. 
Fig. 2 Color Doppler ultrasound of the mass reveals increased blood flow to the periphery of the mass within central flow. 

Discussion: In this case, a real-time ultrasound would be useful to observe if there are 'floating particles' within the mass or not. If present, it would indicate that the mass is not solid, but filled with echogenic materials. With a single gray-scale image (Fig. 1), differential diagnoses are broad - and of course, a real solid mass is not excluded. In Fig. 2, though, a peripheral rim of vascular flow is present without central flow. This finding would be supportive of an abscess or a complicated cyst (hemorrhagic, infected cyst).  However, further action would be needed to confirm it.

Diagnosis: Breast abscess confirmed by ultrasound-guided aspiration.

Points:

• Ultrasound is the primary method for evaluation of young women with breast complaints
  
• In pregnant women with a solid-appearing breast mass, differential diagnoses are fibroadenoma, breast cancer and solid-appearing abscess (like in this case). 
  
• Ultrasound is used to guide interventional diagnostic and therapeutic procedures of the breast.

Reference:

Yang W, et al. Diagnostic breast ultrasound: current status and future directions. Radiol Clin N Am 2007.

When to Perform Breast MRI?

ภาพด้านบน: MRI of both breasts (with gadolinium, subtraction image) แสดงให้เห็น irregular enhancing mass in the left breast ผล biopsy พบว่าเป็น invasive ductal carcinoma (สังเกตว่า เวลาอ่าน breast MRI, right breast จะอยู่ด้านซ้ายของภาพ และ left breast อยู่ด้านขวาของภาพเนื่องจากผู้ป่วยนอนคว่ำขณะทำการตรวจ)

คงเป็นที่ทราบกันดีนะครับว่าการทำ breast cancer screening ในปัจจุบันได้รวมการตรวจทางรังสีวิทยาด้วยการทำ mammography เข้าไว้ด้วย และถือเป็นองค์ประกอบที่สำคัญมาก ในการวินิจฉัย breast cancer พบว่ารังสีแพทย์มีบทบาทในการวินิจฉัย breast cancer มากขึ้นเรื่อยๆ เนื่องจากผู้ป่วยส่วนหนึ่งมาทำ mammogram และเมื่อพบความผิดปกติ รังสีแพทย์ก็ทำ biopsy เลย และในหลายๆ ครั้งก็เป็นหมอคนแรกที่ให้การวินิจฉัยแล้วจึงส่งต่อไปยังศัลยแพทย์ครับ ประโยชน์ของการทำ mammogram นั้นเป็นที่ประจักษ์อยู่ในบทความและหนังสือทั่วไปมากมายนะครับ

อย่างไรก็ตาม ทั้งการตรวจเต้านมและการทำ mammography ก็มีข้อจำกัดที่ไม่สามารถตรวจพบ cancer ได้ 100%. Sensitivity ของ clinical exam นั้นอยู่ที่ 50% ในขณะที่ mammography 68% ถ้ารวมกันจะมี sensitivity สูงขึ้นเป็น 77% ซึ่งก็ถือว่าสูงพอสมควร

ฺBreast MRI ได้เข้ามามีบทบาทมากขึ้นเรื่อยๆ เนื่องจากมี sensitivity สูงมากกว่า 90% ในการ detect breast cancer แต่ข้อด้อยอยู่ที่ specificity ที่ค่อนข้างต่ำกว่าวิธีการตรวจอื่นๆ ปัจจุบัน American Cancer Society (ACS) ก็ได้นำ breast MRI เข้ามาใน recommendation ด้วยครับ

Recommended Indication for Breast MRI Screening (as an Adjunct to Mammography)
1. >20% - 25% calculated lifetime risk of breast cancer (สามารถคำนวณได้จาก website ของ ACS แต่ข้อมูลปัจจุบันยังจำกัดอยู่กับคน Caucasian)
2. Documented BRCA mutation
3. First-degree relative with BRCA mutation
4. First-degree relative with premenopausal breast cancer
5. Radiation to chest between age 10 and 30 years
6. Li-Fraumeni, Cowden, or Bannayan-Riley-Ruvalcaba syndromes, or a first-degree relative with these syndromes

สิ่งควรรู้

• ไม่แนะนำให้ทำ annual breast screening with MRI ในบุคคลทั่วไปเนื่องจาก false positive เยอะ ทำให้อัตราการ biopsy ที่ไม่จำเป็นสูง
• อาจพิจารณาทำ MRI ในผู้หญิงที่ได้รับการวินิจฉัยว่าเป็น breast cancer ใหม่ เพื่อค้นหา additional lesion ใน breast ข้างเดียวกันและข้างตรงข้าม (พบว่าผู้ป่วยที่มี breast cancer มี second focus of cancer ใน breast ข้างเดียวกัน 10% ซึ่งอาจเปลี่ยนแนวทางการรักษาจาก lumpectomy เป็น mastectomy)
  
• แนะนำให้ทำ breast MRI ในกรณีที่พบว่าผู้ป่วยมีแต่ axillary nodal metastasis แต่ไม่พบ primary
  

Reference:
1. Miller JC, et al. When is breast magnetic resonance imaging recommended for cancer detection? J Am Coll Radiol 2008;224-226.
2. Saslow D, et al. American cancer society guidelines for breast screening with MRI as an adjunct to mammography. CA Cancer J Clin 2007;57:75-89.