The Spectrum of Non-neoplastic Changes Associated With Breast Implants: Histopathology, Imaging, and Clinical Significance

Breast implant-associated anaplastic large cell lymphoma has been recognized as a distinct entity in the World Health Organization classification of hematolymphoid neoplasms. These neoplasms are causally related to textured implants that were used worldwide until recently. Consequently, there is an increased demand for processing periprosthetic capsules, adding new challenges for surgeons, clinicians, and pathologists. In the literature, the focus has been on breast implant-associated anaplastic large cell lymphoma; however, benign complications related to the placement of breast implants occur in up to 20% to 30% of patients. Imaging studies are helpful in assessing patients with breast implants for evidence of implant rupture, changes in tissues surrounding the implants, or regional lymphadenopathy related to breast implants, but pathologic examination is often required. In this review, we couple our experience with a review of the literature to describe a range of benign lesions associated with breast implants that can be associated with different clinical presentations or pathogenesis and that may require different diagnostic approaches. We illustrate the spectrum of the most common of these benign disorders, highlighting their clinical, imaging, gross, and microscopic features. Finally, we propose a systematic approach for the diagnosis and handling of breast implant specimens in general.

Imaging of the Reconstructed Breast

The incidence of breast cancer and, therefore, the need for breast reconstruction are expected to increase. The many reconstructive options available and the changing aspects of the field make this a complex area of plastic surgery, requiring knowledge and expertise. Two major types of breast reconstruction can be distinguished: breast implants and autologous flaps. Both present advantages and disadvantages. Autologous fat grafting is also commonly used. MRI is the modality of choice for evaluating breast reconstruction. Knowledge of the type of reconstruction is preferable to provide the maximum amount of pertinent information and avoid false positives. Early complications include seroma, hematoma, and infection. Late complications depend on the type of reconstruction. Implant rupture and implant capsular contracture are frequently encountered. Depending on the implant type, specific MRI signs can be depicted. In the case of myocutaneous flap, fat necrosis, fibrosis, and vascular compromise represent the most common complications. Late cancer recurrence is much less common. Rarely reported late complications include breast-implant-associated large cell anaplastic lymphoma (BIA-ALCL) and, recently described and even rarer, breast-implant-associated squamous cell carcinoma (BIA-SCC). In this review article, the various types of breast reconstruction will be presented, with emphasis on pertinent imaging findings and complications.

Medical Imaging of Inflammations and Infections of Breast Implants

Breast implants are widely used for reconstructive and/or cosmetic purposes. Inflammations and infections of breast implants represent important complications in clinical practice. The proper management of complications is necessary: diagnostic imaging plays a key role in detecting sites of inflammation and/or infection. The present review aims to illustrate the radiological findings of these conditions with different imaging techniques, such as mammography (MX), ultrasound (US), magnetic resonance imaging (MRI), and nuclear medicine imaging. A knowledge of these findings is essential for radiologists and nuclear medicine physicians to provide helpful information for the clinical management of these complications.

Injection mammoplasty: Normal imaging appearances, complications, and implications for mammographic screening

BACKGROUND

The normal imaging appearances of the common agents used in injection mammoplasty and the challenges of mammography screening will be reviewed.

METHODS

The local database from a tertiary hospital was accessed for imaging cases of injection mammoplasty.

RESULTS

Free silicone is seen as multiple high-density opacities on mammograms. Silicone deposits can often be seen within axillary nodes due to lymphatic migration. Sonographically, a snowstorm appearance is seen when the silicone is diffusely distributed. On MRI, free silicone is hypointense on T1-weighted and hyperintense on T2-weighted images, with no contrast enhancement. Mammograms have a limited role in screening due to the high density of silicone. MRI is often required in these patients.Polyacrylamide gel and hyaluronic acid are seen as multiple collections on mammography. Polyacrylamide gel collections are of the same density as cysts, while hyaluronic acid collections are of higher density but less dense than silicone. On ultrasound, both can appear anechoic or show variable internal echoes. MRI demonstrates fluid signal with hypointense T1-weighted and hyperintense T2-weighted signal. Mammographic screening is possible if the injected material is located predominantly in the retro-glandular space without obscuring the breast parenchyma.On mammograms, autologous fat locules appear as lucent masses. Rim calcification can be seen if fat necrosis had developed. On ultrasound, focal fat collections can demonstrate varying levels of internal echogenicity, depending on the stage of fat necrosis. Mammographic screening is usually possible for patients after autologous fat injection as fat is hypodense compared to breast parenchyma. However, the dystrophic calcification associated with fat necrosis may mimic abnormal breast calcification. In such cases, MRI can be utilized as a problem-solving tool.

CONCLUSION

It is important for the radiologist to recognize the type of injected material on the various imaging modalities and recommend the best modality for screening.

MRI for Evaluation of Complications of Breast Augmentation

Breast augmentation is one of the most common aesthetic procedures performed in the United States. Several techniques of breast augmentation have been developed, including the implantation of breast prostheses and the injection of autologous fat and other materials. The most common method of breast augmentation is to implant a prosthesis. There are different types of breast implants that vary in shape, composition, and the number of lumina. The rupture of breast implants is the leading cause of implant removal. The rupture rate increases substantially with the increasing age of the implant. Most implant ruptures are asymptomatic. Implant complications can be grouped into two categories: local complications in the breast and adjacent soft tissue, and systemic complications associated with rheumatologic or neurologic symptoms. The onset of local complications may be early (infection and periprosthetic collections including seromas, hematomas, or abscesses) or late (capsular contraction, implant rupture, gel bleed, or breast implant-associated anaplastic large cell lymphoma). Although mammography is the imaging modality for breast cancer screening, noncontrast breast MRI is the imaging modality of choice for evaluation of the integrity of breast implants and the complications of breast augmentation, for equivocal findings at conventional imaging, and as a supplement to mammography in patients with free injectable materials. The fifth edition of the Breast Imaging Reporting and Data System (BI-RADS) provides a systematic outline for MRI evaluation of patients with breast implants. Silicone- and water-selective sequences provide useful supplemental information to confirm intracapsular and extracapsular rupture. Breast MRI for evaluation of implant integrity does not require intravenous contrast material. The use of MRI contrast material in patients with breast augmentation is indicated when infection or malignancy is suspected. Radiologists should have a thorough understanding of the different techniques for breast augmentation, normal imaging features, and complications specific to breast augmentation. An invited commentary by Ojeda-Fournier is available online. ^©RSNA, 2022.

The Value of Capsule Thickness on Breast Ultrasound as an Indicator of the Severity of Capsular Contracture and Its Correlation with the Baker Classification

BACKGROUND

We conducted this study to explore the value of the capsule thickness as an indicator of the severity of capsular contracture (CC) alternatively to the Baker classification system in patients who were treated with an implant-based augmentation mammaplasty.

METHODS

A total of 117 eligible patients (202 breasts) were included in the current study. We measured the capsule thickness using ultrasound and histologic examination in association with the Baker grades I, II, III and IV. Then, we analysed agreement of the capsule thickness between the two methods using an intra-correlation coefficient (ICC 2,1) with 95% confidence intervals (CIs). The CC of Baker grades II, III and IV (105 breasts), for which the capsule thickness could be measured using US, served as Model 1. Moreover, Model 1 including the CC of Baker grades I (97 breasts) served as Model 2.

RESULTS

The capsule thickness was measured as 0.58 ± 0.11 (0.4-0.8) mm, 1.07 ± 0.16 (0.8-1.31) mm and 1.89 ± 0.55 (1-4.1) mm on ultrasound in association with Baker grades II, III and IV, respectively. In addition, it was also measured as 0.28 ± 0.07 (0.09-0.41) mm, 0.58 ± 0.08 (0.42-0.75) mm, 1.06 ± 0.14 (0.79-1.34) mm and 2.13 ± 1.14 (1.38-6.98) mm on histologic examination in association with Baker grades I, II, III and IV, respectively. In Model 1 and 2, the ICC was calculated as 0.942 (95%CI 0.914-0.961) and 0.955 (95%CI 0.940-0.966), respectively. The cut-off values between the Baker grades I-II, II-III and III-IV were calculated as 0. mm, 0.8 mm and 1.2 mm, respectively.

CONCLUSIONS

In conclusion, the capsule thickness might be used as an indicator of the severity of CC alternatively to the Baker classification system. But further studies are warranted to establish our results.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

PET/CT Variants and Pitfalls in Breast Cancers

There are a number of normal variants and pitfalls which are important to consider when evaluating F-18 Fluorodeoxyglucose (FDG) with Positron Emission Tomography (PET) in breast cancer patients. Although FDG-PET is not indicated for the initial diagnosis of breast cancer, focally increased glucose metabolism within breast tissue represents a high likelihood for a neoplastic process and requires further evaluation. Focally increased glucose metabolism is not unique to breast cancer. Other malignancies such as lymphoma, metastases from solid tumors as well as inflammatory changes also may demonstrate increased glucose metabolism either within the breast or at other sites throughout the body. Importantly, benign breast disease may also exhibit increased glucose metabolism, limiting the specificity of FDG-PET. Breast cancer has a wide range of metabolic activity attributed to tumor heterogeneity and breast cancer subtype. Intracellular signaling pathways regulating tumor glucose utilization contribute to these pitfalls of PET/CT in breast cancer. The evaluation of axillary lymph nodes by FDG-PET is less accurate than sentinel lymph node procedure, however is very accurate in identifying level II and III axillary lymph node metastases or retropectoral metastases. It is important to note that non-malignant inflammation in lymph nodes are often detected by modern PET/CT technology. Therefore, particular consideration should be given to recent vaccinations, particularly to COVID-19, which can commonly result in increased metabolic activity of axillary nodes. Whole body FDG-PET for staging of breast cancer requires specific attention to physiologic variants of FDG distribution and a careful comparison with co-registered anatomical imaging. The most important pitfalls are related to inflammatory changes including sarcoidosis, sarcoid like reactions, and other granulomatous diseases as well as secondary neoplastic processes.

Imaging Spectrum of Augmented Breast and Post-Mastectomy Reconstructed Breast with Common Complications: A Pictorial Essay

Breast augmentation is becoming more common, be it for cosmetic reasons or post-mastectomy. Multiple articles in the literature describe the imaging findings of various types of cosmetic breast augmentation. Some articles describe imaging findings for different types of post-mastectomy reconstructions. This essay aims to serve as a comprehensive reference for the multimodality imaging of various types of breast augmentations in native breast and post-mastectomy reconstructions. Familiarity with these findings will facilitate the detection of complications and new or recurrent breast malignancies in patients. With the extensive illustrations provided in this essay on normal and abnormal imaging findings of augmented breasts, readers will receive exposure that will facilitate effective practice.

Understanding Silicone Breast Implant-Associated Complications for Radiologists

미용적 성형 및 유방암 수술 후 재건의 목적으로 사용되는 실리콘 보형물의 사용이 국내외에서 크게 증가함에 따라 진료 영역에서 실리콘 보형물 삽입술을 받은 환자들을 어렵지 않게 접하게 되었다. 기존에 알려져 있던 보형물의 파열이나 구축과 같은 합병증 외에 최근에는 유방 보형물 연관 역형성 대세포 림프종과 같은 악성 종양과의 연관성도 보고되면서 보형물 관련한 영상 검사가 증가하고 있다. 이러한 상황에서 영상의학과 의사들은 보형물 삽입술을 받은 환자에 대해 어떤 검사가 필요하고 어떤 영상 소견이 보형물 관련 합병증을 시사하는지에 관한 충분한 지식을 갖추고 있어야 할 것이다. 본 종설에서는 영상의학과 의사들이 알아야 하는 실리콘 보형물의 다양한 합병증과 이들의 영상 소견에 대해 다루고자 한다.

Primary High-Grade Angiosarcoma of the Breast in a Young Woman With Breast Implants: A Rare Case and a Review of Literature

Primary angiosarcoma (AS) of the breast is an extremely unusual variant of breast malignancies, and its incidence is about 0.05% of all primary breast tumors. In this article, we present a rare case of a primary AS that developed in a young woman with breast implants. This case report emphasizes importance of early investigation for accurate diagnosis and proper management of the breast AS, along with a correlation of histopathologic, radiologic, and clinical findings.

The skinny on skin: MRI features of cutaneous and subcutaneous lesions detected on body MRI studies

The skin and subcutaneous tissues are inevitably imaged as part of most body MRI studies. Incidental or even symptomatic skin lesions may, therefore, be detected and present a diagnostic challenge for the radiologist. We aim to provide a comprehensive review, with illustrative examples, of the skin abnormalities encountered on body MRI studies in our busy academic radiology department.

Sonography in capsular contracture after breast augmentation: value of established criteria, new techniques and directions for research

Capsular contracture or capsular fibrosis is the most common complication following breast augmentation with implants. Sonography is usually the initial imaging test performed to examine a suspicious implant. In contrast to the large number of patients developing capsular fibrosis there is only sparse literature reporting about sonographic findings. In this letter after a brief review of normal sonographic findings after breast augmentation, established ultrasound findings suggestive of capsular fibrosis (deformity, increased number of radial folds and thickening of the fibrous capsule) are discussed. The possible value of new techniques and possible directions for further research are addressed.

Imaging of common breast implants and implant-related complications: A pictorial essay

The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer.

The Effect of Breast Implants on Mammogram Outcomes

Breast cancer detection in women with implants has been questioned. We sought to evaluate the impact of breast implants on mammographic outcomes. A retrospective review of women undergoing mammography between March 1 and October 30, 2013 was performed. Demographic characteristics and mammogram results were compared between women with and without breast implants. Overall, 4.8 per cent of 1863 women identified during the study period had breast implants. Median age was 59 years (26–93). Women with implants were younger (53.9 vs 59.2 years, P < 0.0001), had lower body mass index (25.4 vs 28.9, P < 0.0001), and were more likely to have dense breast tissue (72.1% vs 56.4%, P = 0.004) than those without. There were no statistically significant differences with regards to Breast Imaging Recording and Data System 0 score (13.3% with implants vs 21.4% without), call back exam (18.9% with vs 24.1% without), time to resolution of abnormal imaging (58.6 days with vs 43.3 without), or cancer detection rate (0% with implants vs 1.0% without). Because implants did not significantly affect mammogram results, women with implants should be reassured that mammography remains useful in detecting cancer. However, future research is required to determine whether lower call back rates and longer time to resolution of imaging findings contribute to delays in diagnosis in patients with implants.

Magnetic resonance imaging of breast implants

Silicone breast implants have significantly evolved since their introduction half a century ago, yet implant rupture remains a common and expected complication, especially in patients with earlier-generation implants. Magnetic resonance imaging is the primary modality for assessing the integrity of silicone implants and has excellent sensitivity and specificity, and the Food and Drug Administration currently recommends periodic magnetic resonance imaging screening for silent silicone breast implant rupture. Familiarity with the types of silicone implants and potential complications is essential for the radiologist. Signs of intracapsular rupture include the noose, droplet, subcapsular line, and linguine signs. Signs of extracapsular rupture include herniation of silicone with a capsular defect and extruded silicone material. Specific sequences including water and silicone suppression are essential for distinguishing rupture from other pathologies and artifacts. Magnetic resonance imaging provides valuable information about the integrity of silicone implants and associated complications.

Breast reconstruction with a deep inferior epigastric perforator flap: imaging appearances of the normal flap and common complications

OBJECTIVE

The purpose of this essay is to illustrate the normal imaging appearance of deep inferior epigastric perforator (DIEP) flap breast reconstruction and common postoperative complications.

CONCLUSION

Familiarity with the anatomy and normal imaging appearance of a DIEP flap reconstruction will help the breast imager recognize normal postsurgical findings and common postoperative complications.

Three-dimensional thermoacoustic imaging for early breast cancer detection

PURPOSE

Microwave-induced thermoacoustic tomography (TAT) is a noninvasive modality based on the differences in microwave absorption of various biological tissues. In this paper, the feasibility of the early breast tumor detection by TAT system has been discussed and validated experimentally.

METHODS

A fast TAT system, which based on three 128-elements transducers, a 384-64ch switch and a parallel data acquisition system (DAS), was developed to reconstruct the three-dimensional (3D) image of a breast model with similar microwave absorption coefficient to breast tissue. A novel method to explore the ability of TAT system to distinguish absorption coefficient was introduced and the minimum absorption coefficient difference that can be distinguished clearly by our TAT system is 12 m(-1).

RESULTS

The potential applications of the TAT system were clearly demonstrated by successfully mapping breast model with mimicked tumors and microcalcification. An imaging experiment of human breast tumor embedding in the breast model was performed and the tumor was visualized by the 3D thermoacoustic volume.

CONCLUSIONS

The thermoacoustic images match well with the samples and achieve penetration depth of 6 cm. The experimental results indicate that TAT has a great potential to be used for detecting early-stage breast cancers with high contrast and high resolution.

Dual-energy CT for the evaluation of silicone breast implants

OBJECTIVE

The evaluation of breast implants for rupture is currently the domain of ultrasound and MRI, while mammography is of very limited diagnostic value. Recently, specific visualisation of silicone has become feasible using dual-energy CT. Our objective was to evaluate whether it is feasible to identify silicone in breast implants by dual-energy CT and to reliably diagnose or rule out ruptures.

METHODS

Seven silicone breast implant specimens were examined on dual-source CT at 100- and 140-kV tube potential with a 0.8-mm tin filter (collimation 128 × 0.6 mm, current-time products 165 and 140 mAsref with modulation, rotation time 0.28 s, pitch 0.55). Two patients scheduled for implant removal or replacement were examined with identical parameters.

RESULTS

The silicone of the implant specimens showed a strong dual-energy signal. In one patient, both implants were intact, while a rupture was identified in the other patient. Ultrasound, MRI, surgical findings and histology confirmed the dual-energy CT diagnosis.

CONCLUSION

Dual-energy CT may serve as an alternative technique for speedy evaluation of silicone breast implants. Specific clinical studies are required to determine the diagnostic accuracy and define indications for this technique.